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Productivity and diversity of rocky intertidal macroalgae in relation to a seasonally fluctuating environment Pecchioli, Joel Albert 1984

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PRODUCTIVITY AND DIVERSITY OF ROCKY INTERTIDAL MACROALGAE IN RELATION TO A SEASONALLY FLUCTUATING ENVIRONMENT By JOEL ALBERT PECCHIOLI B. S. , Southampton College  A THESIS SUBMITTED  o f Long I s l a n d U n i v e r s i t y ,  IN PARTIAL FULFILLMENT OF  THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES (Department o f Botany)  We accept t h i s t h e s i s as conforming to the r e q u i r e d  standard  THE UNIVERSITY OF BRITISH COLUMBIA April  1984  © J o e l A l b e r t P e c c h i o l i , 1984  1981  In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an advanced degree a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y purposes may be g r a n t e d by t h e head o f my department o r by h i s o r h e r r e p r e s e n t a t i v e s . It is understood that copying o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n permission.  Department o f  fYPt/vY  The U n i v e r s i t y o f B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date  //  Ap#-/t~  /^Y  ii  ABSTRACT  the  The p r o d u c t i v i t y , d i v e r s i t y and community s t r u c t u r e  of  intertidal  of  macroalgal  Bamfield, B. C , period  (June  examined exposure.  to August 1983).  representative Algal  and,  along  standing  weekly i n t e r v a l s ; these diversity  in  Canada were s t u d i e d over 1982  as  community  crops  a  vicinity  fifteen  month  Four study s i t e s were a  gradient  were  data were  the  of  estimated  wave  at semi-  used to c a l c u l a t e  algal  i n c o n j u n c t i o n with concurrent measurements  of p h o t o s y n t h e s i s , a l g a l p r o d u c t i v i t y .  Fucus d i s t i c h u s  most  of  abundant  at  the  upper  levels  s h e l t e r e d s i t e s where i t formed an lower  shore  series (  of  at  Leathesia  fenestrata  annual  difformis ,  F. d i s t i c h u s  extensive  the s h e l t e r e d s i t e s was  spring/summer  ,  etc.).  abundance  wave  levels  were  Standing crop of a l l s p e c i e s and  l e a s t i n winter.  very low greater  in on  those lower  The  species  woodii  ,  Ulva  increased,  Mid-shore l e v e l s at the an  by  was  canopy.  exposure  decreased.  dominated  more  ephemeral  Cryptosiphonia  As  three  c h a r a c t e r i z e d by a  and  exposed s i t e were c h a r a c t e r i z e d by lower  the  was  "algal  turf"  Hedophyllum  greatest i n  while  sessile  spring/summer  At the s h e l t e r e d s i t e s , d i v e r s i t y areas  levels  dominated of  the  by shore.  was  Fj^ d i s t i c h u s  and  Diversity  was  iii greatest  i n the mid-shore  exposed  site  H.  sessile  the  and  exposure) result  lower  (lower)  observed  vertical  the  in  dominated  and seasonal  of  "algal  (tidal  interactive  ) and t h e p r e s e n c e  distichus  and  was  was  positively  Photosynthetic  rates  that  daylength,  se  more  responsible  ,  was  differences  i n net d a i l y was  action  during  the f a l l / w i n t e r  It  proposed  wave stress  action during  observed  that  summer.  wave  for  a l l year, limited  and  scutulata  and  photosynthesis  in  and e a r l y  water  flux  the  year,  density  Positive but  summer  temperature.  observed  algal  and  the  were  per  seasonal net d a i l y  increased standing  productivity  and winter  (wave  action  throughout  the  that  canopy  and not photon  E\_ d i s t i c h u s  i n the f a l l the  little  photosynthesis.  productivity  was  with  the  d i v e r s i t y were  the spring  correlated  indicating  proposed  horizontal  of  daily  at  (upper) and  o f a F\_ d i s t i c h u s  during  varied  was  (by L i t t o r i n a  Net  greatest  It  effects  L.  F.  distichus  of a l g a l  Herbivory  influences.  assemblage  height),  patterns  stress.  secondary  the  zones.  desiccation sitkana  turf"  wave crops.  i s limited  by  nutrient/desiccation  iv  TABLE OF CONTENTS  Page  Abstract  1  L i s t o f Tables  1  v  L i s t of Figures  viii  Acknowledgements  xi  Chapter One: I n t r o d u c t i o n  1  Chapter Two: Environmental M o n i t o r i n g Program  8  Chapter Three: Biomass o f I n t e r t i d a l Macroalgae  37  Chapter Four: I n v e r t e b r a t e Abundances  99  Chapter F i v e : D i v e r s i t y o f the Macroalgae  . .  134  Chapter S i x : P r o d u c t i v i t y of t h e Macroalgae  165  Concluding  270  Remarks  Summary  275  References C i t e d  278  Appendix  A: P h o t o s y n t h e s i s - I r r a d i a n c e  Curves  299  V  LIST OF TABLES  Page 1.  Wave exposure r a t i n g s a t each study s i t e  2.  C o r r e l a t i o n matrix f o r selected a b i o t i c factors .  3.  4.  5.  6.  7.  8.  9.  10.  11.  12.  30 environmental 34  Per cent time exposed to a i r f o r each zone and s i t e f o r s e l e c t e d months Sampling i n t e r v a l s f o r each s i x - week o r two "sample month" L i s t of study  intertidal  macroalgae  study 44  - month 45  c o l l e c t e d d u r i n g the 48  Combined ( t o t a l ) a l g a l s t a n d i n g crop [g d r y wt m-2; ( s t d . dev.)] f o r each zone a t the study s i t e s averaged o v e r the e n t i r e study p e r i o d  50  A n a l y s i s of v a r i a n c e of combined a l g a l (g dry wt m-2) a t each study s i t e  51  s t a n d i n g crop  M u l t i p l e r e g r e s s i o n analyses of t o t a l a l g a l s t a n d i n g crop (g d r y wt m-2) at a l l s i t e s and zones on s e l e c t e d a b i o t i c environmental f a c t o r s , A n a l y s i s of v a r i a n c e of Fucus d i s t i c h u s s t a n d i n g crop (g d r y wt m-2) i n Zones I and I I a t each study s i t e  54  ,  61  Multiple r e g r e s s i o n . analyses of Fucus distichus standing crop (g d r y wt m-2) at a l l s i t e s and zones on s e l e c t e d a b i o t i c environmental f a c t o r s . . .  67  Multiple regression analyses standing crop (g d r y wt m-2) s e l e c t e d a b i o t i c environmental  68  of Fucus distichus f o r each zone on factors . . . . . . . .  A n a l y s i s of v a r i a n c e of L e a t h e s i a d i f f o r m i s s t a n d i n g crop (g dry wt m-2) i n Zone I I I a t Haines, Helby and Wizard f o r 1982 and 1983  75  vi Page  13.  14.  15.  Multiple regression analysis of Leathesia difformis s t a n d i n g crop (g d r y wt m-2) on s e l e c t e d abiotic environmental f a c t o r s  75  M u l t i p l e r e g r e s s i o n a n a l y s i s of Cryptosiphonia woodii s t a n d i n g crop (g d r y wt m-2) on s e l e c t e d abiotic environmental f a c t o r s  77  Summary of analyses species  79  s t a n d i n g crop data (g d r y wt m-2) and of v a r i a n c e f o r the common secondary  16.  A n a l y s i s o f v a r i a n c e o f Cladophora spp. s t a n d i n g crop (g d r y wt m-2) a t each study s i t e  17.  Analysis of variance of L i t t o r i n a s i t k a n a d e n s i t i e s (# 0.0625 m-2) i n Zones I and I I a t the study s i t e s  .  118  A n a l y s i s o f v a r i a n c e of L i t t o r i n a s c u t u l a t a d e n s i t i e s (# 0.0625 m-2) i n Zones I and I I a t the study s i t e s  .  1  18.  19.  20.  21.  22.  23.  24.  83  M u l t i p l e r e g r e s s i o n a n a l y s e s o f L i t t o r i n a s i t k a n a and L i t t o r i n a scutulata d e n s i t i e s on s e l e c t e d a b i o t i c e n v i r o n m e n t a l f a c t o r s and Fucus d i s t i c h u s s t a n d i n g crop Fucus d i s t i c h u s clearing experiment: standing crops (g d r y wt m-2) and d e n s i t i e s (# 0.0625 m-2)  1  9  121  macroalgal littorine 1  2  2  Fucus d i s t i c h u s clearing experiment: a n a l y s i s o f variance of Fucus d i s t i c h u s standing crop (g d r y wt m-2) i n the e x p e r i m e n t a l quadrats  ^  Fucus d i s t i c h u s clearing experiment: analysis v a r i a n c e of l i t t o r i n e d e n s i t i e s (it 0.0625 m-2) the e x p e r i m e n t a l q u a d r a t s  124  of in  M a c r o a l g a l s t a n d i n g crop and d i v e r s i t y d a t a f o r Cape B e a l e i n the summer 1983 . . . . . . . M u l t i p l e regression analyses o f s p e c i e s r i c h n e s s and d i v e r s i t y on s e l e c t e d a b i o t i c environmental f a c t o r s  1  .  3  2 3  9  ^ - ^ l  vii Page  25.  26.  27.  28.  29.  30.  31.  Ash-free (organic) d r y weight (g AFW g DRY-1) f o r s e l e c t e d macroalgae d u r i n g each six-week sampling interval Summary of m e t e o r o l o g i c a l d a t a on those days when d i u r n a l p h o t o s y n t h e s i s experiments were performed Summary o f t h e d i u r n a l f o r Fucus d i s t i c h u s  Analysis of variance of photosynthesis and r e s p i r a t i o n o f Fucus d i s t i c h u s from Zones I and I I at Helby  190  Results of multiple regression a n a l y s e s o f net and g r o s s d a i l y p h o t o s y n t h e s i s (mg C g d r y wt-1 d-^-1) of Zone I and I I Fucus distichus from Helby on s e l e c t e d a b i o t i c e n v i r o n m e n t a l f a c t o r s  197  Summary o f the d i u r n a l p h o t o s y n t h e s i s experiments f o r Hedophyllum s e s s i l e  206  M u l t i p l e r e g r e s s i o n a n a l y s e s of n e t and g r o s s d a i l y photosynthesis(mgC g d r y wt-1 d-1) i n Hedophyllum s e s s i l e on s e l e c t e d a b i o t i c e n v i r o n m e n t a l f a c t o r s  33.  Summary o f d i u r n a l p h o t o s y n t h e s i s experiments s e l e c t e d i n t e r t i d a l macroalgae  36.  37.  38.  39.  186  187  Ln s i t u b l a d e growth  35.  .  p h o t o s y n t h e s i s experiments  32.  34.  184  i n Hedophyllum  sessile  207 209  for  Daily and annual n e t p r o d u c t i v i t y f o r i n t e r t i d a l macroalgae a t Haines  selected  Daily and annual net p r o d u c t i v i t y f o r i n t e r t i d a l macroalgae a t Helby  selected  Daily and annual n e t p r o d u c t i v i t y f o r i n t e r t i d a l macroalgae a t Wizard  selected  Daily and annual n e t p r o d u c t i v i t y f o r i n t e r t i d a l macroalgae a t Nudibranch  selected  Summary o f d a i l y and annual marine b e n t h i c macroalgae  .  226  232  234  236  238  n e t p r o d u c t i v i t y by  Calculated and e s t i m a t e d parameters o f the PS v I r e l a t i o n s h i p o f s e l e c t e d i n t e r t i d a l macroalgae . . .  262  322  viii LIST OF FIGURES  Page  1.  2.  Schematic diagram o f the r e l a t i o n s h i p s between v a r i o u s a b i o t i c environmental f a c t o r s , biotic interactions, m a c r o a l g a l p r o d u c t i v i t y and m a c r o a l g a l s t a n d i n g crop Map o f the study a r e a i n the v i c i n i t y B r i t i s h Columbia, Canada  . 10  of Bamfield 12  3.  Monthly means o f a i r and water temperature, and d a i l y photon f l u x d e n s i t y a t t h e B a m f i e l d Marine S t a t i o n . . 19  A.  Monthly means o f s u r f a c e s a l i n i t y and seawater + n i t r i t e c o n e n t r a t i o n a t each study s i t e  5.  General  diagrams  of  the  intertidal  e s t a b l i s h e d a t each study s i t e 6.  7.  8.  nitrate 2  3  transects .  ^1  Mean s t a n d i n g c r o p (+ o r - one s t a n d a r d d e v i a t i o n ) of Fucus d i s t i c h u s i n Zones I and I I a t each study s i t e f o r each "sample month"  56  Mean s t a n d i n g crop (+ & - 1 s t a n d a r d d e v i a t i o n ) Hedophyllum s e s s i l e i n Zone I I I a t Nudibranch each "sample month"  65  of for  Mean standing crops of Leathesia difformis, C r y p t o s i p h o n i a w o o d i i , and C o r a l l i n a V a n c o u v e r i e n s i s at each semi-weekly sample time i n Zone I I I at Haines, Helby, and Wizard d u r i n g t h e s p r i n g and summer o f 1982 and 1983  7  1  2 9.  Diagram o f t h e 1 m experimental p l o t s Fucus d i s t i c h u s c l e a r i n g experiment  s e t up i n the 104  2 10.  Mean d e n s i t i e s (number p e r 0.0625 m ± one s t a n d a r d d e v i a t i o n ) o f L i t t o r i n a s i t k a n a i n Zones I and I I a t each study s i t e f o r each "sample month"  108  Mean d e n s i t i e s (number p e r 0.0625 m ± one s t a n d a r d d e v i a t i o n ) of L i t t o r i n a s c u t u l a t a i n Zones I and I I a t each study s i t e f o r each "sample month"  113  2  11.  I X  Page  12.  13.  14.  15.  16.  17.  18.  19.  20.  21.  Species r i c h n e s s and macroalgae a t Haines interval  diversity o f the i n t e r t i d a l f o r each six-week sampling  Species r i c h n e s s and macroalgae a t Helby interval  diversity o f the i n t e r t i d a l f o r each six-week sampling  140  142  Species r i c h n e s s and d i v e r s i t y o f the i n t e r t i d a l macroalgae a t Wizard f o r each six-week sampling interval  144  Species r i c h n e s s and d i v e r s i t y o f the i n t e r t i d a l macroalgae a t Nudibranch f o r each six-week sampling interval  146  Summary o f the cluster analysis s i t e - z o n e - t i m e biomass m a t r i x  152  P l o t of exp(H') stress  of  the  reduced  a g a i n s t wave exposure and d e s i c c a t i o n 158  D i u r n a l curves of n e t p h o t o s y n t h e s i s for Fucus distichus from Zones I and I I a t Helby (mean ± 1 standard d e v i a t i o n )  191  D i u r n a l curves of n e t p h o t o s y n t h e s i s distichus from Zone I a t Nudibranch standard d e v i a t i o n )  200  for Fucus ( mean ± 1  D i u r n a l curves of n e t p h o t o s y n t h e s i s f o r Hedophyllum sessile from Zone I I I a t Nudibranch ( mean ± 1 standard d e v i a t i o n )  203  D i u r n a l curves o f n e t p h o t o s y n t h e s i s for spp. ( mean ± 1 s t a n d a r d d e v i a t i o n )  212  Cladophora  22.  D i u r n a l curves of n e t p h o t o s y n t h e s i s f o r C o r a l l i n a V a n c o u v e r i e n s i s ( mean ± 1 s t a n d a r d d e v i a t i o n ) . . . . 214  23.  D i u r n a l curve of n e t p h o t o s y n t h e s i s f o r C r y p t o s i p h o n i a woodii  24.  25.  (mean ± 1 s t a n d a r d d e v i a t i o n )  . . . . . . .  216  D i u r n a l curves of net- p h o t o s y n t h e s i s f o r H a l o s a c c i o n americanum (mean ± 1 s t a n d a r d d e v i a t i o n )  218  D i u r n a l curves of net photosynthesis for Leathesia difformis (mean ± 1 s t a n d a r d d e v i a t i o n )  220  X  Page  26.  27.  28.  29.  30.  31.  32.  33.  34.  v.  D i u r n a l curves of n e t p h o t o s y n t h e s i s f o r NeorhodOmela larix (mean ± 1 s t a n d a r d d e v i a t i o n ) . . . . . . .  222  D i u r n a l curves of net photosynthesis f o r fenestrata (mean ± 1 s t a n d a r d d e v i a t i o n )  224  Ulva  P h o t o s y n t h e s i s - i r r a d i a n c e curves f o r Fucu9 d i s t i c h u s from Zone I a t Helby  .  P h o t o s y n t h e s i s - i r r a d i a n c e curves f o r Fucus d i s t i c h u s from Zone I I at Helby .  3  P h o t o s y n t h e s i s - i r r a d i a n c e curves f o r Fucus d i s t i c h u s from Zone I at Nudibranch Photosynthesis - irradiance s e s s i l e (21 May 1983)  curve  for  305  3  0  12  Hedophyllum 1  3  Photosynthesis - i r r a d i a n c e curve v a n c o u v e r i e n s i s (29 A p r i l 1983)  for  Photosynthesis - i r r a d i a n c e d i f f ormis  for  curves  P h o t o s y n t h e s i s - i r r a d i a n c e curve f o r U l v a (7 A p r i l 1983)  9  Corallina  ' .  4  316  Leathesia 3  fenestrata . . . . . . . .  1  8  320  ACKNOWLEDGEMENTS  I  would  first  R. E . F o r e m a n , work  of  research.  D. G l a s s ,  described  know  discuss  the research  on  staffs  B. C. B o t a n y  made  life  that  "superb".  comments  U.  the  much  Hawkes  assisted  with  algae.  I am a l s o  indebted  were  Julie  thanks  (especially  invaluable.  I  - can only  be  willingness  Marine  to  David  Island  Library  was a g r e a t  help i n  performed  Garbary  Band  study  fellow  Station,  Biomedical  Rimmer  to the Ohiat  would  i nt h e  f o r experimental  indentification  : your  was  R. E . D e W r e e d e ,  and  Bunting  Padilla  i t  believed  -  Bamfield  Oliveira,  t o a l l my  a t U. B. C .  and  help.  and L e s l i e  the  Dianna  also  a n d Woodward  t o use the Haines  Special  officemates  manuscript,  Barbara  analyses.  else  suggestions  the  nitrate  At times, the  a n d P. J . H a r r i s o n  of  easier.  and t h e freedom t o  interest.  committee  a great  i n the greenhouse  BMS  someone  were  Department  supervisor,  overwhelming,  Their  working  permission  was  research  advice,  personal  P. G. H a r r i s o n  design,  my  h i s support,  thesis advisory  as  The  thank  involved  to My  to  of great  work  encouraging  A.  for  on a p r o b l e m  amount  like  and  o f some  cooking,  like  of the me  site. students  and C h r i s t i n e Cooke)  also  Michael  f o rgranting  graduate  jokes,  the  to  and thank  at  a n d my  frienship Murray  xii Schneider  and  Catherine  p e r s p e c t i v e on the  for  helping  me  keep  my  research.  T h i s research was of  Tetu  U. B. C. Graduate  supported  directly  Fellowships  to  through  a  series  J . A. P e c c h i o l i  i n d i r e c t l y v i a Science C o u n c i l of B r i t i s h Columbia Grants  and to  R. E. Foreman. Finally, father:  I would l i k e to d e d i c a t e  thanks  watching . . . ) .  for  everything  this  thesis  to  my  (...and I know you've been  1  C H A P T E R ONE  Marine  ecosystems  North,  1971; J o h n s t o n Mann,  many  fish The  annual St.  Excretion  indicated  be  a  budgets Johnston  proportion  apparently  and n u r s e r y  o f Mann  producers agents.  grounds f o r  which  exceeded rrr  C  the grazed  the  1982).  2  the  (Khailov  vs  macroalgae  carbon  carbon  fixed in  and  energy  and Burlakova,  Eventually,  1969;  a l l of the  (see Chapter  areas,  macroalgal  herbivores  the 2  by  temperate  intertidal  of  in  190 g C m" ) .  c a n be s u b s t a n t i a l  by  primary  (1972b): the  that  (DOM)  of  of  In  as  by b e n t h i c m a c r o a l g a e  g  part  systems.  actively  Smith,  terrestrial  primary  the study  portion  ecosystems  of  in  plants  (603  and a major  biomass,  1963;  1981;  these  Scotia  e t a l . , 1977; Mann, plant  o f many  Ryther,  structuring  organic matter  considerable  enters detrital  small  of  by  three-fold  for coastal  part  species.  Nova  of d i s s o l v e d  photosynthesis  3),  a r e both  p r o d u c t i o n of o r g a n i c matter  phytoplankton  benthic  macroalgae  importance  Bay,  1957;  counterparts  provide the habitat  potential  Margaret's  may  their  spatial/temporal  beds  is  important  and H e l f r i c h ,  and i n v e r t e b r a t e  producers  a r e an  e t a l . , 1977; G u t e r s t a m ,  Like  benthic  important  Macroalgal  (Kuhn  1982).  communities, and  INTRODUCTION  benthic macroalgae  coastal  1981;  -  only  a  biomass  is  (Mann,  1973;  2 Hawkins is  and  Hartnoll,  incorporated into  1983);  food  webs  areas.  Smith  (1979)  has  litter  from  a  in the  into  coastal  thus  are  of  the  community ecological 1963;  and  1969). of  trophic  of  level  Studies macroalgae  have  of  studies  examined  Parker,  1981)  periods  and  productivity 1973).  1973; or  only  been  have  measured  ( e . g.  or  1966;  the  webs. of  a  other  Paine,  here, first  1966;  is  the  (producer)  productivity limited the  two  1973;  methodological  data 1969;  high  1982). (e. g.  Most Wassman  Schramm, over  and  include  changes  1976a;  short  estimate  Towle  problems  biomass  potentially  and  to  marine and  species  King  of  scope  1973,  productivity  these  on  food  community  (Mann,  Johnston,  measurements  and  productivity  used  of  indicated  Zavodnik,  waters  (Westlake,  primary  one  large  - ~  plants  extrapolated  Other  productivity  these  for a  It  the  into  generally  webs.  of  (or carbon)  the  but  of  plant  comprehension  as  examining  food  coastal  Margalef,  1965).  productivity  Ramus,  1964;  (Westlake,  applicability,  and  further  coastal  i s transported  account  primary  biomass  the  filter-feeding  productivity,  energy  have  have  to  Orias,  Primary  flow  the  energetic aspects  C o n n e l l and  Mann,  and  and  of  Georgia  p r o d u c t i o n of  of  i s fundamental  80%  macroalgae  detrital  plant  benthic  that of  the  i t enters detrital  primary  understanding  of  i n nearby  Strait  benthic  i n many  most  concluded  where  that  important An  rate  waters  appears  proportion  site  thus  time annual  Pearse, basing  (which  can  3 greatly  underestimate  Brinkhuis, part  1977c)  of  the  or  day  photosynthetic  and  1981).  Very  estimate  macroalgal  photosynthesis primary 1977; kelp  Hatcher  et  of  The various  been  1977;  intertidal  understood. et  a l . (1980)  species  of  shown  that  while  the  times.  may  limiting Lindley, perennial  1980).  macroalgae  are  between  Chapman  Gagne in  limit of  store  growth  during  part  (Chapman  ability may,  may  be  and  nitrogen  and  1972b;  be  in part,  Gerard  1973). and  species,  Craigie  (1977,  Lindley  (1980),  on  the  various  Arctic  of  limiting  or  and  long-term  few  carbon  Craigie, may  (Mann,  a l . (1982) and  ambient  and  and  Scotia  nitrogen  various  for a  Nova  nitrogen  a l . ,  productivity  and  of  of  (Zavodnik,  except  to  annual  et  and  macroalgal  are, of  rare  et  This  Hatcher  a l . , 1977;  and  respectively, growth  et  Chapman  availability  to  calculate  detail  in  Kremer,  programs  productivity  a l . (1977),  L a m i n a r i a may  when,  The  macroalgae  Laminaria light  to  1977a,b,c;  Johnston  work  only  changes  1980;  s i m i l a r comprehensive  The  during  sampling  year  i n some  factors  1972b;  c o n c u r r e n t measurements  complete  relationships  et  combined  with  studied  Mann,  diurnal  Rosenberg,  a l . , 1977).  However,  Hatcher  have  (Brinkhuis  environmental  1978),  use  has  et  a l . ,  1979).  studies  Mann  a  see  possible  and  biomass  productivity  species  poorly  studies  —  photosynthesis  ignoring  (Ramus  over  Johnston  Mann,  measuring  rates few  productivity  have  the  year  at  other  for  light  later  levels  are  Chapman  and  characteristic  of  1977;  explain  the  observed  4 high  productivity  and  North,  1980;  The  attached  habit  by  waves and  nutrients factor down  and  of  may  limit  and  Mann,  1979;  The  environmental studies  tidal  macroalgae exposed  been  t o a i r and et  1982).  submergence mechanism (Johnston  et  a l . , 1979;  they  are  to  by  that  t o be  1976;  breaking  around rates  the of  Parker,  water  the  and  motion (Gerard  exposure the  a l . , 1974; and  10-25%  has  the tidal  by  fluctuating cycle.  when  Schonbeck Brown,  plants a l . ,  a l . , 1979;  and  1982;  Norton, Oates  to  as  are 1974;  Dring  to  intertidal  may  intertidal  et  implicated of  uptake  the  photosynthesis  zonation  Recent  macroalgae  some  (Johnson et  been  intertidal  nutrient  greatest  of  with  intertidal  Quadir  response  Dring  By  of  of  important  productivity  complex  imposed  shown  influencing  an  1980;  levels  Photosynthesis  a l . ,  and  high  c r o p s and  desiccated  The  (Wheeler,  photosynthesis  cycle. has  Brinkhuis Brown,  of  be  enhance  demonstrated  adaptations  also  may  more  as  conditions  have  replenishment  motion uptake  washed  a l . , 1980). is  exposed  1982a).  productivity.  however,  et  Ramus,  layers  standing  Mann  Wheeler  continually  constant may  1978;  ( i . e . boundary  nutrient  situation  macroalgae,  a  g a s s e s , and  1982);  and  macroalgae,  macroalgal  algal  (Topinka,  Rosenberg  ensures  water  and  Gerard,  and  1982;  to d i f f u s i o n  thalli),  1981;  plants  benthic  dissolved  photosynthesis  et  Mann,  currents,  barriers  the  these  influencing  plant  show  of  and  periodic a  possible  macroalgae 1978; and  Quadir Murray,  5  1983).  These  plants  advantage  of  nutrients  (Thomas  The  the  main  increased  may  limited and  Turpin,  goal  of  macroalgal  productivity  number  workers  abiotic  periods  factors  rocky  intertidal  Lodge,  1950;  of  Menge,  Sousa,  1979;  Lubchenco,  Hawkins, 1981;  1981,  Underwood  Jernakoff, of can  algal be  Hawkins to  productivity  drawn  from  and  properly  these  plants.  1983;  et  1981;  limited  evaluate  the  seasonally  between  net  productivity,  determinations and  the  the  standing ecology  of crop  and  structuring and  Cubit,  1974;  Menge,  1978; 1980;  Sousa  et a l . , 1982;  However,  lack  and  the  which  Gaines,  studies are  1981; needed  between  intertidal  fluctuating  of  Kastendiek,  interactions strategies,  A  Burrows  and  algal  community  environment. as  estimated  The with  photosynthesis of  an of  the c o n c l u s i o n s  Long-term  growth  in  a l . , 1981;  a l . , 1983).  has  role  Underwood,  1983).  physiological  into  1980,  acquire  importance  1972;  Lubchenco  Hartnoll,  a  insight  1978;  (Lubchenco  structure,  respiration,  Connell,  up  communities.  1948;  studies  algal  relationship  data  these  productivity, and  1975;  take  take  and  the  (Lodge,  Jernakoff,  Underwood  to  interactions  S a n t e l i c e s et  and  1983;  intertidal  1976,  1983;  is  demonstrated  to  to  1983).  in rocky  1971,  1974,  Thomas,  magnitude  biological  Paine,  submergence  research  communities  Dayton,  of  adaptations  the  have  and  show  1980;  this  understanding  of  also  macroalgae  environmental  may  and provide  physiology  of  6 F i v e main o b j e c t i v e s this  the  course  of  research:  1) intertidal  to  quantify  macroalgae  and  environmental f a c t o r s , and  are approached i n  the  relate  productivity this  to  of  a  rocky  number  of  such as l i g h t , n u t r i e n t a v a i l a b i l i t y ,  herbivory; 2)  to  examine  the  relationship  p h o t o s y n t h e s i s , i n the form of net p r o d u c t i v i t y ,  between and  algal  standing crop; 3)  to  a l g a l photosynthetic  examine  diurnal  rates  and  and seasonal changes i n  relate  these  changes  to  problems 1 and 2 ; 4)  to study p a t t e r n s of a l g a l s p e c i e s d i v e r s i t y  along both the (wave  vertical  exposure)  diversity  (tidal  gradients  and  exposure) to  and  relate  horizontal  algal  species  to p r o d u c t i v i t y ; 5)  to  examine  macroalgal p r o d u c t i v i t y Although  this  the  relationship  and i n t e r t i d a l community  between structure.  study cannot provide d e f i n i t i v e answers  to each of the above-mentioned problems  —  the  limitations  imposed by geography and time are apparent — the information gained should provide i n s i g h t the  ecology  of  rocky  i n t o the r o l e of macroalgae i n  intertidal  i n t e r t i d a l organisms i n t e r a c t  communities.  i n a number  of  complex  Rocky ways  7 with  their  environment  concerning  such  understanding development  of of  and  with  each  interactions these  general  can  communites  ecological  other.  Any  only and  to  principles.  information add  the  to  our  further  8 CHAPTER 2 - ENVIRONMENTAL MONITORING PROGRAM  Photosynthesis  and  r e s p i r a t i o n , the primary metabolic  processes determining a l g a l p r o d u c t i v i t y , various ways.  environmental Ecological  factors  processes,  processes, may f u r t h e r  in  algal  Temperate l a t i t u d e s g e n e r a l l y number on  affected  from  physiological  productivity.  have seasonal c y c l e s  of a b i o t i c f a c t o r s which may be important  productivity.  herbivory  biotic  in a  influences  interactions,  such  as  competition,  may  l i m i t a l g a l standing crop  (thus reducing p r o d u c t i v i t y )  and  be  agent  in  and  Also,  by  complex and i n t e r a c t i v e  distinct  influence  are  the  intertidal  community.  understand the e f f e c t s of some of productivity,  selected  a  these  environmental  major In  structuring  order to b e t t e r  factors  on  algal  parameters  were  monitored throughout the study: 1)  light  2) a i r and water temperature 3) seawater n i t r a t e c o n c e n t r a t i o n 4)  salinity  5) wave exposure 6) i n v e r t e b r a t e 7) tidal Figure interactions  1  is a  between  abundances  cycle  schematic  diagram  of  those a b i o t i c and b i o t i c  the  possible  f a c t o r s most  9 likely  to  these  influence  factors  interactions changes  in  Variations  may  on  of  the  and  Norton,  The  Study  The  work  has  Gunnill,  Canada  (48°  also  be  Seasonal of  growth,  considered may  be  intertidal  completed  macroalgae  conducted Barkley  52' deep  30"  upwelling  of  spot"  important  tidal  range  datum;  Institute  a  major  community  on  this  aspect  (Lewis,  1977;  Hruby  Underwood  N,  water,  125°  et  a l . ,  during  highest  tides  i n December  sites  evaluations,  as  were  30'  the  chosen,  W; is  fishery 4.1  m  Sciences,  tides  vicinity  1983).  a  (-0.2  Sydney,  January. on  areas  2).  B.C., Due  "biological  to  and  Bamfield  Island,  (Thomson,  morning  based  the  Figure  early  representative  of  Vancouver  area  commercial  Ocean  the  07'  this  is approximately of  in  Sound,  low  Five  cycles  of  factor  effects.  with  and  1980;  and  individuals  been  intertidal  was  Station,  the  of  Each  Area  Marine  lowest  must  productivity  of  1979;  study  and  coupled  recruitment  little  ecology  productivity  recruitment,  algal  productivity.  synergistic-  factors,  the  but  algal  affect  produce  and in  structure,  may  these  reproduction  influence  intertidal  +3.9 B.C.)  in  the  initial along  a  1981). m  to hot The  Canadian with  the  summer  and  subjective gradient  of  10  Figure 1  Schematic  diagram  between  various  factors,  biotic  productivity,  of  the  relationships  abiotic  environmental  interactions,  and m a c r o a l g a l  macroalgal  standing  crop.  Tide Cycle Light Temperature Nutrients Water Motion Salinity  Net  Productivity  —* DOM  Herbivory  Excretion Wave A c t i o n Others  «—  • Standing Crop  12  Figure 2  Map of  of the study area Bamfield, B r i t i s h  i n the  vicinity  Columbia, Canada.  14 wave  exposure  consisted and  (Figure  of  solid  exposed,  Island,  (hereafter and  called  as  coast",  per  confines  of  breakwaters Channel. even  during  substrate L.  and  fairly  a l .  Channel  winter  storms.  this  the  small  affected  shelf  form the  winter  ways  of  tidal  bed  of  of upper 1983.  at  Beale  "Nudibranch",  four  sites  and  Beale  flat  shelf  can  as  be  "open  by  within  the  natural  heavy  swell  in Trevor  usually  minimal,  is  O f f s h o r e of a  the  bed  of  to  Haines  heavy  site,  Zostera  the  swell  strong  the  marina  of  past sand,  by  In the  shells  .  Human  above  the  shelf  (i.e.  i n the  a  winds  flow  clearing of  Cape  two  the  integrifolia  levels  Helby  behind  However,  consists  land  a  from  currents  substrate  on  similar  action  to  Bory.  protected  wave  and  "Wizard",  site  populated  breakwaters).  rapid  the  many  Island,  Haines  Point,  i t from  severe  is in  granodiorite  are  and  at  and  site  (1968).  is located  protect  increase  Offshore,  and  et  each  sheltered  coast"  action  flat  northwest  in  outer  grained  first  wave  natural  a  The  Macrocystis integrifolia  relatively  with  site  i s sandy  Helby  of  sites  at  From most  "Helby",  2).  Ricketts  which  The  study  "protected  Dodger  medium  1974).  "Haines",  Haines  substrate  Nudibranch  Figure  designated as  five  Islet,  "Beale";  The  (Muller,  the  Wizard  The  p l a t f o r m s of  quartz diorite  most  2).  a  series  from  the  addition, Helby and  site.  cobble,  disturbance, site,  may  have  fall  of  1982  15 Wizard  i s located at the juncture  Satellite  Passage,  tidal  wind-induced  and  blocks on  most  the  M.  protected  when  reduced than  when  that  the winds  at the three and  obtained  at Nudibranch  of  An  the  extensive  southwest  Beale  luetkeana  (Mert.)  Post.  et  of t h i s  site.  to  the  heavy south;  the north,  wave wave  action  action i s  but s t i l l  sites.  Due  lies  greater  to  1982 a n d  luetkeana  i s an e x t r e m e l y  entrance  the onshore  to Barkley  swell  occasions  in  the*  dominated  by  Postelsia  californianus most  Sound.  Beale  summer  Conrad,  exposed  exposed  shores  of  was  severe  could  be  late-March  just  offshore  1983.  an a s s e m b l a g e and  of land  at the  i s no p r o t e c t i o n  Ocean.  visited  palmaeformis  (Rigg  point  There  of the P a c i f i c  conditions,  1979).  of  December  bed o f N^  hazardous  the  beds  no q u a n t i t a t i v e d a t a  between  laid  Small  more p r o t e c t e d  conditions,  were  site.  Cape  from  sea  Island  Wizard.  from  a r e from  and  strong  Helby  and the t r a n s e c t s  i s exposed  are  Channel  to fairly  However,  of  offshore  site  weather  1983.  swell  side  swells  exposed  currents.  just  Nudibranch  oceanic  is  and N e r e o c y s t i s  are located The  thus  of the oceanic  integrifolia  Rupr.  and  of Trevor  Because on  only  The shore Rupr.  two  a t Beale and  characteristic Miller,  of the  1949;  is  Mytilus of  only  Paine,  16 Methods  and  Materials  Thrice PST,  of  water  daily  photon  cover,  Station.  depth  LICOR  PAR,  of  0.5  obtained At  was  m.  from  P.  least  study  once  measurements  of  the  measured  temperature more  complete  (BMS).  4)  wave  The  were data water  the  or  obtained  at  measured  with  a  Instrument  obtained using  study  parameters  data  a was  period were  (June  measured  temperature  nitrate  from  each  taken  mercury  concentration  action  taken  0.5  was  Marine  comm.).  water  seawater  of  depth  a i r and  3)  at  was  and  Beale):  salinity  at  a  Precipitation  during  2)  were  air  Bamfield  was  I600h  conditions  (Lambda  flux  following  (except  transects a  week  the  1)  All  photon  and  nm),  either  PFD  meter  (pers.  each  1983), site  with  Integrator.  Janitis  the  temperature  Quantum  LI-500  400-700  at  measured  daily  1200h,  meteorological  made  Water  0800h,  Instantaneous  Total  t o August  each  were  LI-185  Model  (PFD;  general  thermometer.  Model  LICOR  and  etc.)  Corporation).  at  density  Temperature  red-alcohol  1982  at  temperature,  (cloud  a  flux  measurements,  a  boat  site.  m.  The  at  temperature  to  Water v a l u e s of  for purposes  collected  10  the and  of  50  m  offshore  temperature air  and  comparison  Bamfield Marine salinity  data  was  water  with  the  Station for Beale  17 were  p r o v i d e d by t h e B a m f i e l d M a r i n e Surface  125  ml a c i d  for  washed  nitrate  chloroform, later  determined CDM  2e  plaguing  II  with  intertidal  difficult action  30  ml  the  a  or  Samples  few d r o p s  laboratory,  (1972).  of and  concentration  Auotoanalyzer  was  and  the  Salinity  was  a conductivity  meter  water  h a s been  (1981), action  relative At  t o one each  (Type  rankings",  It  meaningful Druehl  back  best  (1981)  methodology  (Muus,  method  and 1968;  In l i g h t  subjective  available  It  evaluated 1968)  lacking.  on a  years.  quantitative  Demetropoulous,  procedures  fallen  f o r many  a  of  measure of  t o rank  sites  another.  visit  shore,  exposure.  both  the  1 t o 10, b a s e d the  and  construct  I have as  obtain  (Jones  1971) a n d f o u n d  Druehl  to  movement  ecologists  and c u r r e n t s .  plaster-of-par is  travel  in  with  nitrite)  of nearshore  drogue-technique  Doty,  of  to  and Parsons  i n the laboratory  f o r wave  wave  (+  Technicon  of S t r i c k l a n d  extremely  data  of  a  preserved  returned  Nitrate  using  collected  polypropylene bottles.  were  when  measurement  problem  the  were  Radiometer).  The  the  analysis  analyzed.  methodology  samples  ( 1 0 % HC1)  frozen  determined  is  seawater  Station.  to each on  was  t o the study  site,  the sea s t a t e made  should  as severe  study  be  to  sites.  subjective  and degree  describe  noted  weather  a  that  conditions  the  of  rating  "pounding"  observed  these often  are  wave  "minimal  prohibited  18 Results  a)  Light  and  The the  light,  a i r and water  Bamfield Marine  three the,  abiotic  lowest  January) to  Temperature  Station  factors  values  data  a r e summarized  showed  a strong  recorded  and the highest  temperature  in  collected  in Figure  3. A l l  seasonal pattern,  the  winter  values recorded  at  with  (November  i n t h e summer  to  (June  August). Mean  monthly  November  1982 a n d  monthly  water  highest,  16.0° C  3.4°  C  less  1982).  similar  (June  than  daily to  site No  analyses,  1982).  mean  a i r  PFD p e r of 2  were  1983.  The  Water  temperature  each  and  2  month  water  data  data  other  differences  t h e BMS  a  1.0-  November  seasonal  temperature.  a i r temperature  between-site  was  temperatures  observed  to each  1983) a n d t h e  (except  r e c o r d e d i n June 1  mean  were  months.  showed  day"  6.0° C i n  lowest  (January  t h e summer  was  1  comparable  therefore,  between  a i r and water  day"  and  ranged  6.6° C  month  of 3 E i n rrr  water  was  a i r temperature  that  value  The  data.  temperature  o f 33 E i n r r r  minimum  i n August  constant during  Mean  study  18.3° C  Monthly  relatively  value  a i r temperature  will  were  pattern A  maximum  .1982  and  i n December collected and  to  apparent.  be u s e d  and  a  1982. at  each  the  BMS  In a l l assumed  19  Figure 3  Monthly means of  a i r and water  temperature,  and d a i l y photon f l u x d e n s i t y at the B a m f i e l d Marine S t a t i o n .  •  = A i r Temperature  •  = Water  Temperature  A = Photon Flux  Density  Month  o  21  to  be  representative  However,  the  during  the  1982-83,  April  air  and  Daily  variation  with  the the  the  JJE  ITT  April  to  mean,  1 2 0 0 h ) was  August  Seawater  The  September always and  1982  greater  usually  nitrate  1983. 220  slightly  lower  the  winter  averaged  3.8°  C  least  recorded  s"  daily  mean,  in C).  1.0° (3.0°  C C)  (0.1°C).  to  greater  August  recorded  i n December  1  1982  I200h)  i n June  C),  (0.6°  averaged  i n June 1982  (5.4°  variation  1983  temperature  lowest  2  1982  and  PFD  than  1982  and  (monthly  1982.  Concentration  data  collected  4a-d.  A  at  each  general  values  March  than  exceeded  1983.  2.5 6.0  concentration  were  yg-at  high  is  and  Nitrate  ug-at  NO^  l "  NO^l~ .  occurred  1  at  study  seasonal  nitrite) concentration  site, and  site.  during  January  recorded  rrr  pE  each  September  i n December  The  in Figures  each  water  (monthly  were  (+  in  variation  1  C),  (5.4°C);  surface  Nitrate  nitrate  At  1983  PFD  nitrate  presented surface  s"  2  was  higher  (5.5°  variation  1000  Beale  at  sites.  recorded  maximum  Instantaneous  B)  1982  was  minimum  at  in a i r temperature  August  in  conditions  and  other  i n June  temperature  and  1982,  variation  greatest  and  at  the  temperature  summer  than  Daily was  water  of  1  site  are  pattern  in  apparent. variable  between  concentration during A  these  marked  a l l sites  months  drop  in April  was  in 1983.  22 From  April  below 1.0  to August  2  pg-at  1983  pg-at NO^l" .  NO^  samples  exceeding  not  in  the  10  levels and  1  collected  concentrations included  1~  I t s h o u l d be  1  seawater  nitrate  noted, in  pg-at  consistently  usually  less  than  however,  that  three  June NO^l"  calculated  were  1983  had  nitrate  (these values  1  means p r e s e n t e d  in  were  Figures  4a-d) .  C)  Salinity  The in  salinity  Figures  month  4a~e.  observed  Salinity Haines  and  The from  was  salinities  period  were:  ppt;  for  Haines  basis,  Haines/Nudibranch to  September  the  rest  of  August  greatest  Nudibranch  seasonal  only  Nudibranch  surface  25.0  collected  Salinity  to another.  maximum  at  data  the  -  27.6 27.6  the and  1982 year.  tended  at  ppt;  over Helby  Beale  differences  greatest  and  were (and  — -  presented  greatly  1982  from  trend at  and  each  greater  Wizard. entire  25.7  ppt;  in  more  Mean study  Wizard  ppt.  On  salinities  least  a  site.  the  29.7  one  was  generally  to Helby  site  are  seasonal  Beale,  ppt;  site  to vary  to October  Helby/Wizard and  each  evident  compared each  —  at  during  variable)  — a at  August during  23  Figure A  M o n t h l y means o f s u r f a c e and  seawater  concentrations  nitrate  +  at each  A)  Haines  B)  Helby  C)  Wizard  D)  Nudibranch  E)  Beale  #  =  •  = N0  salinity nitrite  study  (salinity  Salinity 3  + N0  2  site,  only)  Month  28  29 D)  Wave  Action  The rating  data  scale,  evident, winter  action at  wave  based  the  on  degrees  and  was  very  Stronger  was  was  arc  The  following  used  -  open  a  subjective  seasonal  calmer  seasonal  trend i s  i n the f a l l  (April  to  change  and  conditions September). i n the  p a t t e r n s were  (1970)  wave  observed  to  for calculating  for this  between the  study.  wave  sea.  ( i n degrees  Haines  148; B e a l e  —  0;  -  182.  of  —  index  T h i s method i s  fetch the  o f a r c ) were Helby  an  exposure A  due t o t h e g e o g r a p h y  data  sites:  Nudibranch  and  seasonal  adapted  the r e l a t i o n s h i p  km)  1983)  little  A  occurring  a n d summer  of Baardseth  exposure  of  1.  on  Nudibranch.  method  7.5  study  exposure  spring  at Haines.  The of  in  based  in Table  1982 t o M a r c h  there  Wizard  exposure,  greatest  (October  that  wave  are presented  with  prevailing Note  for  of  and  1 km ( n o t  study  obtained  25;  the  area. f o r the  Wizard  —  81;  Discussion  The factors noted  values  recorded  monitored  during  by o t h e r  workers  for  the  the study  for Barkley  various  period Sound.  environmental  agreed  with  those  Table  MONTH  1.  Wave e x p o s u r e  HAINES MIN EXP  1982  1983  MAX EXP  ratings  HELBY MIN EXP  at  each  WIZARD  MAX EXP  MIN EXP  study  site.  NUDIBRANCH  MAX EXP  MIN EXP  MAX EXP  MEAN MIN  MEAN MAX  August  2  3  6  1. 3  3.0  September  2  5  6  1. 3  3. 5  October  1  3  8  1 .8  3.5  November  3  3  7  1. 5  3 . 5  December  3  6  7  2. 5  4 . 3  January  2  6  8  3. 5  4.3  February  3  4  8  2.0  4 . 3  March  2  3  4  1. 8  2 . 5  Apr i 1  1  4  3  1. 3  2 . 3  May  1  2  5  1. 3  2.8  June  2  2  5  1. 3  2. 5  July  1  4  5  i .0  2.8  August  1  3  4  1 .0  2.3  Mean  1.2  1.1  1.8  1.8  3.7  2.6  5.8  O  31 Thomson 8°  C  here:  This  27.6  was  recorded  (located  between  Emmet  showed  (pers.  higher  decreasing  waters  of Barkley nitrate  (pers.  comm.  nitrate  )  phytoplankton  chlorophyll phytoplankton 1982  bloom  nitrate  (28-32  water  bloom was  during  not  concentration  Figure  The  2) b y  however,  gradient  of  to Haines/Nudibranch of wind  with  observed  the  were  and  and t i d e estuarine  1983. July  (pers. at  Emmet  5  paralleled  1  by  4a-d).  to  R.E. Foreman decline in  with  comm.  )  meters  a  spring  noted  an  depth  in  i n mid-February to  also  and August  1982.  similar  The s h a r p  pg c h l 1~  (Figures  Anchorage  o f 5 m,  1983 c o i n c i d e d  (a+b+c)  i n October  levels  e t a l . , 1971).  B . Emmet  i n mid-March  Similar  Mackenzie  the result  levels  5  (25.0  .  a depth  Beale  reported  i n J u n e 1982.  ppt).  from  in April  from  levels  of values  L.D. D r u e h l  chlorophyll  1  Barkley  for  Islands;  f o rthe Bamfield area.  Anchorage  pg c h l l "  from  (Austin  bloom.  in  Mackenzie  Water  by  concentration  increase  Diana  + nitrite  recorded  at  and  coastal  Sound  summer  site  water  probably  salinity  of 6 to  oceanic waters  observed  was  of high  those  Helby  salinities  mixing  The  pure  comm.).  Helby/Wizard  each  surface  salinity  in the  temperatures  t o t h e range  at  below for  C  water  1983 a n d 1 6 . 0 ° C  salinity  ppt)  were  27  average  i s comparable  6.6° C i n J a n u a r y The  to  cited  i n t h e w i n t e r a n d 18-20°  Sound.  B.  (1981)  recorded  high  1982 a n d a  fall  However, a decline  the  October  i n seawater  32  Ammonium generally (<1.5  and  low  and  ug-at  pers.  NH  comm.).  nitrogen  Thus,  nitrate  1983  (>10  due  Although  been  very  subjective  importance"  at  Helby,  showed  whereas  wave  and  winter  sites  can  be  plus  number  of  than  the  exposed  was  type  sites  tank). site than  in  wave  Haines A  seasonal  at  least  this  Haines  be  the  Druehl, source  given  pulses  of  to  in  water  whose  the June were  column.  of  nitrate  growth  greater  may  be  was  Island.  exposure,  during  the  suggests  Beale  First  (wave  solids)  at  ranked  more  a as  (comparable  to  exposed  significantly Beach,  the  groups.  was  (probably  ranked  fall  that  scouring  suspended  sheltered  site  and  i n wave  relative of  "relative  Haines  exposure  Cape  very  Island  study)  This  two  i s of  sites,  change  the  Sound.  Island  Helby  major  exposure  sheltered  concentration  in Barkley  and  of  quantified  and  these  Nudibranch.  into  L.D.  concentrations of  plants  noticeably  and  ;  1  summer.  two  little  divided  exposed  "calm"  The  Wizard  (1980)  action  a  very  mixing  infrequent,  the  the  are year  sporadically  elevated  to  l "  4  Inlet  the  should  observed  ranking  best.  action  at  Craik  most  during  P0  Emphasis  important  Bamfield  throughout  storm-increased and  the  i s probably  These  1  to  in  yg-at  plants.  NC^l" ).  nitrogen-limited The  <1  nitrate  short-lived  have  ;  1  concentrations  ug-at  probably  levels  constant l "  for marine  high  could  phosphate  more  comparable  to  33 Wizard Helby  Islet, Island  The of  (1970)  and  the  supportive  A on  a  the  less  study  evidence  >  of  combined  method  other  workers  exposure  ranking  with  of at  the  Bamfield  given  > Helby  correlation  analysis  ( M I D A S ) was  at  on  environmental  the  light  the each  the  are  to  the  algal six  and salinity,  nitrate,  each  site.  The  performed  of  a i r and  factors  1200h,  and  water  temperature,  nitrate  during water  (e.  1600h),  and  wave  and g.  daily total exposure  site.  to  of  be  biomass  factors  salinity,  Haines  instantaneous  temperature  0800h,  >  monitored  means  various  and  results  factors  with  flux,  air  data  factors  i n c l u d e d monthly  at  in  collected  abiotic  light  PFD  and  study  then  Beale.  > Wizard  diurnal  precipitation,  to  the  the  exposed  Pt  daily  variations  analyses  Cape  (1980),  using  with  for  These  instantaneous  Based  than  Craik  sites  thirty-seven  temperature, integrated  of  Nudibranch  multiple  study.  reduced  exposed  more  sites:  Beale  set  significantly  discussion  study  Cape  and  ranked  observations  ranking  five  was  wave  this used  analysis, in  and  other  fifteen  future  in  and  Table  has 2  a i r exposure  factors,  number  of  correlation  productivity  presented exposure  the  which  been  and  the  data  for  involve  Table  2  Correlation  F 1 - m o n t h l y mean a i r temperature (°C)  matrix  environmental  factors  F2  F3  F4  F5  F6  1.0000  0.9151  0.9295  -.7841  0.6047  0.5999  1.0000  0.9564  -.9001  0.6990  0.6874  1.0000  -.8913  0.7043  0.7326  1.0000  .7192  -.6691  1.0000  0.5730  F 3 - m o n t h l y mean d a i l y 1 i g h t f 1 ux E i n irr ) 2  F4-monthly t o t a l r a i n f a 11 (mm) F 5 - m o n t h l y mean d a i l y variation air-T C O F 6 - m o n t h l y mean d a i l y v a r i a t i o n w a t e r - T (' C) significance  abiotic  F 1  F 2 - m o n t h l y mean w a t e r t e m p e r a t u r e (' C)  For  for selected  p<0.01, r=0.6411  1.0000  35 diurnal  variations  represented  in light  by t h e i r  Significant P<0.01) w e r e and  water  however, the  positive  found  between  and  t h emonthly  (Table  2).  Table  2).  nitrate  suggests  that  at  (r=0.8989,  significant  that  regimes.  Only  with  a l l of  correlated  study  site  with  with  (r=0.6439-  salinity.  significant  these  factor  Nitrate  Nudibranch likewise  one o t h e r  and two  site  and  affecting  This  source of  levels  correlated  at (r>  most 0.81,  and Wizard  c o r r e l a t i o n was  r=0.6617,  groups  may  positively  for Helby  were  in salinity  thus  algal  were  pairwise  Wizard,  The d i f f e r e n c e s  (25.0 v s 27.6 p p t )  positively  a  rainfall  d i r e c t l y or i n d i r e c t l y( v i a  and  p<0.01);  (Haines  suggesting  important  either  Haines  (r=0.8375, p < 0 . 0 l ) .  salinity  monthly  runoff).  Salinity correlated  system,  be  light, a i r  (r=-0.669l t o -0.9001,  a t each  may  of  correlated  b u t was n o t c o r r e l a t e d  for this  terrestrial  means  R a i n f a l l was p o s i t i v e l y  rainfall  adequately  (r=0.9151-0.9564,  Total  factors  concentration  are  means.  correlations  temperature  0.7976, p < 0 . 0 l ) ,  large  monthly  was s i g n i f i c a n t l y i n v e r s e l y  seawater  nitrate  respective  temperature  light  P<0.01;  and temperature,  not  p<0.0l),  indifferent were  have  not that been  an  productivity. sites p<0.0!  were  significantly  f o r a l lbut t h e  36 Haines/Helby each  site  correlation; was  r=0.6055,  exposed  to  a  0.01  < p  relativly  <  0.05).  similar  Thus, nitrogen  regime. Only  the  Nudibranch) the  wave  This  i s not  more  showed exposure  variation  exposure,  light  Nudibranch  vs vs  total  fairly  accurate,  abiotic  factors  storms  the  subjective as  i t  usually  (i.e.  rainfall).  correlations  exposure  and  Helby.  were  others  r =  correlated  decreased  with  light  and  -0.79). found  Wizard  These  quite  wave  -0.85;  were  at  wave  little  to  to  however,  of  factors.  correlated  -0.44  rainfall  rating  between  general,  = -0.54  p<0.0l).  associated  In  r  and  showed  negatively  others  monthly  (Wizard  environmental  correlations,  (r=0.6580-0.7376,  that  sites  other  wave  Haines  exposure  and  suggest  increased  for  exposure  exposure  and  temperature  positive  Nudibranch  and  at  and  maximum  Significant between  ratings  surprising,  minimum  study  significant positive  seasonal  (Wizard  exposed  and  correlations exposure  well  winter  with  was those  conditions  temperature,  and  37 CHAPTER  Basic  to  3 -  any  determination  of  Macroalgae  a  growth cent  show  forms.  cover  algal  study  primary  data  the  only  abundances,  addition,  per  biomass  other  areas  measure The  affect  plant  variety  cent  and  between  absolute  g.  algal  interactions  plant  factors  also  to  be  and  Mann  (1979) d e m o n s t r a t e d  on  the  thallus  Pyl. light,  limiting  l o n g i c r u r is  plant  with seasonal  nitrogen.  The  sheltered  site  site.  of turn  density  differing  different  exposed  in  end  growth result  was While  more  only  such  1977).  In  patterns with using  biomass.  in Chapter  For  Laminaria  2  may  crops;  factor  example,  Gerard  of  water  motion  longicruris  de  influenced competition at  one  site.  morphologies  that  productive  increased  as  importance  patterns was  i t measures  possible  standing  expected. the  morphology  T h a l l u s morphology  also  per  relative  Comparisons  discussed  and  using  different  1983). are  as  Neill,  show  abundance,  physiology  are  may  the  system.  about  misleading,  Thorn,  species  environmental  both  data  the  abudances  (see  is  three-dimensional  information be  cover  in  complex  dimensions  (e.  productivity  macroalgal  may  two  MACROALGAE  biomass  of  provides and  data  of  of  Estimating  in only  a  INTERTIDAL  wide  abundances  than  BIOMASS OF  and L^  water  also to  longicruris plants  motion  for  Laminaria  abilities  than  la  from may  showed take  up  from  a  a  more  enhance  38 rates  of photosynthesis  Parker,  1981;  limited  by  Mann  Gerard, the  environmental  1982),  same  e t a l . , 1980).  water  Multiple  factors,  physiology,  and  insight  the ecology  into  There quantified some  of  (Blinks,  Munda  and  macroalgal essential  chapter biomass to  (Gerard  algal  standing i n Chapter  of  macroalgae.  few  1976,  1982; C h o c k of  presents and  five  and  the  and  only i n any 1 977;  1983;  Thorn,  have  used  abundance. data  on  structure problems  regression analyses crop  have  Neill,  macroalgae  basic  community the  1977;  of a l g a l  the  which  differences  and Mathieson,  intertidal  further  macroalgae,  at seasonal  algal  produce  studies  be  1979;  crop,  may  looked  may  involving  productivity intertidal  1980;  a n d Mann,  standing  of i n t e r t i d a l  2.  crop  regression analyses  algal  addressing  Multiple  discussed  motion  a s an e s t i m a t e  1.  Chapter for  cover  (Wheeler,  standing  1955; B r i n k h u i s ,  studies  uptake  algal  relatively  have  Markham,  Most  This  been  the biomass these  percentage  algal  have  detail  1983).  and n u t r i e n t  intertidal which  is  presented  in  are also  environmental  performed factors  39 Methods  the  and  Materials  Three  parallel  lower  intertidal,  sites  (note: only  data  collected  Each  transect  neighboring  as  to  was  Each At  distichus species, Zones  noted  similar  for  by  Helby L.,  and  each  presented (2m)  wide  one  and  large  amount  in  species  workers  at  the  to  study  Beale;  the  Chapter  5).  separated  from  meter were  upper  of  in  transects  the  was  and  Zone  II  I I I by  are  their  divided  Wizard,  (1m).  used  at  of  Three  each  site  small-scale  distributions  (Jones  by a  and  "Beard  Zone  I  Pelvetiopsis  1imitata  consisting  of  a  species,  series  et  a l . ,  and 1979;  of  relatively Zone  with  by  Fucus  spring/summer  annuals.  "  to  II  by  the  (1961a), Fucus  large III  zones.  secondary  dominated Zone  three  dominated  equivalent  with  into  some  Stephenson  Gardn.,  and  I was  F\_ d i s t i c h u s  Zone" was  vertically  Zone  essentially  Stephenson  Nudibranch,  distributed  at  the  established  least  other  Zone  II  of to  be  from  1981).  I and  Z o n e  at  intertidal  transect  Haines,  by  was  meters  variability  Underwood,  established  will  two  transects  horizontal  extending  transect  Beale  account  abundances  were  one  at  representative so  transects,  by  F^  by  an  Main  with  Fucus  Zone  III  Outliers".  At  d i st ichus  and  number  "algal of  Hedophyllum  turf"  patchily sessile  40 (C.  Ag.)  similar  Setchell. to  that  Stephenson  and  difformis division  of  best  vertical  Mathieson, Tidal  "Rocky  been  (Rigg  winter)  heights  at  each  so  along  site a  five were  sampled  to  over  and  described  that  based  workers,  intertidal  by  Leathesia  on  and  This species  is  into  1949;  perhaps  meaningful  Stephenson  and  Hardwick-Witman  and  25  sampled The a  from  six-week Each  month".  Table  more  each than  25  was  cm  site,  zone  period, six-week 4  lists  during  of  the  month". the  one  course  tidal  the  per  to a i r . during  randomly  2  the  chosen  of  the  transects  in a  set  sequence  three  period  the  of  intervals  visited the  schematic  showing  m )  to  (Oceanographic are  exposed  using  reference  summary  (0.0625  were  "sample  once  5a-d  (monthly  each  transects  sampled.  for  x  each  site  intervals  seven  with  3 presents a  each  determined  Bamfield  Figures at  were  rod,  for  Table at  transect  stadia  B.C.).  etc. zone  site.  "sample  interval  each  each  transects  bi-weekly  were  seemed  Nudibranch.  zones  1977;  heights  the  zones,  that  at  Miller,  Neill,  level  of  quadrats  and  except  other the  Nudibranch  1983).  Sydney,  At  by  units  Institute,  time  done  at  Victoria"  rare  into  for dividing  1949;  Near  (1961b),  method  tidal  cent  Shores  intertidal  predicted  heights,  community  A r e s c h . was  has  surveyor's  diagrams  algal  Stephenson  the  Stephenson,  a  of  (L.)  distributions the  The  transects  has real No of  been  each  treated  time quadrat the  at  as  sampling area  study.  was  Figure 5  G e n e r a l diagrams  o f the i n t e r t i d a l  e s t a b l i s h e d at each study s i t e . are i n meters above  transects  Tidal  heights  lower low water.  A) Haines B) Helby C) Wizard D)  Nudibranch  C h a r a c t e r i s t i c Species Fd = Fucus  distichus  C l = Cladophora spp. Ld = L e a t h e s i a  difformis  Cv  Vancouveriensis  = Corallina  Cw = C r y p t o s i p h o n i a w o o d i i PI = P e l v e t i o p s i s Hs = Hedophyllum  limitata sessile  42  Haines  A-  » Cw | i  r"  4 Horizontal  1 12  r  1  20  Distanoe(m)  C-  Wisard  I I  6 Horizontal  IO Distance  (m)  Table  3.  Per cent  SITE :  time exposed  to a i r f o r each zone and s t u d y  HAINES  ZONE : TIDAL HT*  I .80  HELBY  II 1.90  III 0.90  I 2.40  II 1.80  site  for selected  WIZARD III 0.70  I 2.40  II 1.40  months  NUDIBRANCH III 0.80  I 2.80  II 2.00  III 1.20  86  53  21 18  MONTH 1982 : June  86  50  12  69  46  69  29  10  October  78  41  10  60  39  60  26  78  40  February  68  32  50  29  50  14  68  34  June  86  48  11  68  42  68  25  86  51  19  81  44  10  65  41  65  26  81  48  18  1983:  1982  Note:  Total  * meters  above  lower  low w a t e r ;  heights  are the lowest  8  vertical  extension  of  the zone  45 Table  4.  Sampling or  "SAMPLE  MONTH"  intervals two-month  f o r each "sample  DATES  six-week  month".  SAMPLES  COLLECTED  1982:  June August September November  6 18 31 13  June - 9 J u l y J u l y - 22 A u g u s t August - 2 October O c t o b e r - 13 N o v e m b e r  1983:  January March Apr i 1 May June August  10 5 18 27 10 22  D e c e m b e r - 23 J a n u a r y February - 5 March M a r c h - 19 A p r i l A p r i l - 31 May J u n e - 14 J u l y J u l y - 27 A u g u s t  46  All stored  the macroalgae were c o l l e c t e d in  separate  plastic  Bamfield Marine S t a t i o n  bags,  g  after  submergence  s u r f a c e water by b r i s k l y each  species  were  c o n v e c t i o n oven  for  0.5  then  quadrat, to  Fresh biomass to  the  of each  the  nearest  to 1.0 h and removal of  the  dried  each  returned  measured  shaking  f o r at l e a s t  were c a l c u l a t e d .  and  for analysis.  a l g a l s p e c i e s i n each quadrat was 0.1  from  plants.  at  105°C  Samples in  a  of  gravity  24h and f r e s h r d r y weight  ratios  Unless otherwise noted, a l l biomass values  are expressed i n terms of dry weight. The  biomass  variance  data  techniques  analyses  (MIDAS).  were  analyzed  (UBC*GENLIN)  and  using  analysis  multiple  of  regression  Those quadrats l a n d i n g on bare  rock,  in  t i d e p o o l s , or c o n t a i n i n g e x c e s s i v e l y l a r g e amounts of algae were  not  used  in  these  analyses.  contained a l g a l s p e c i e s d i f f e r e n t rock were  (see a l s o Lubchenco, usually  Tide pools generally  from those on the emergent  1978), while areas  of  bare  found only at the the top of the t r a n s e c t s and  above the Fucus zone.  O c c a s i o n a l l y , quadrats were c o l l e c t e d  which c o n t a i n e d 800-1000 g dry wt of p l a n t m a t e r i a l 16 kg dry wt i r r ) ; 2  analysis  because  the a l g a l because  rock  these  samples  were  not  used  (i.e. in  up the  they were o b v i o u s l y not r e p r e s e n t a t i v e of  assemblage.  The  UBC*GENLIN  program  i t can handle m i s s i n g data r e s u l t i n g  was  used  from u n s u i t a b l e  47 quadrats  or  conditions,  transects  not  being  sampled  due  to  weather  etc.  Results  A  total  during one  the  of  Table  5  distribution  each  the of  species each  macroalgal  site,  averaged  are  (ANOVA)  over  of  the  over  the  and  crop  entire  7).  The  only  found  for  Zone  and  three-way  (p<0.0l), on  algal  sites  standing  Haines  can  be  4)  the  placed  into  2)  abundant  rare  species.  abundances  i n groups  data  for  1-3  fifteen An was  each (15)  and  will  zone  month  a n a l y s i s of performed  interaction  be  (S-N-K) m u l t i p l e  divided  into  Helby,Wizard  >  of  study  variance on  this were  terms.  three  crop:  >  found  non-significant differences  Student-Newman-Keuls the  6.  month  (Table  Using  and  were  detail.  data  the  be  perennials,  species  in Table  zone,  generally  species,  of  standing  presented site,  can  macroalgae  collected;  degrees  Total  of  abundant  secondary  in various  period,  species  species  1)  common  lists  (60)  The  groups:  3)  discussed  sixty  study.  four  annuals,  of  Nudibranch  range  groups  tests based  48  Table  5.  List  of  intertidal  c o l l e c t e d during  Abundant p e r e n n i a l Fucus d i s t i c h u s L. Hedophyllum s e s s i l e Abundant annual  macroalgae the  study.  species: (C. Ag.)  Setch.  species:  C r y p t o s i p h o n i a woodi i ( J . Ag.) J . L e a t h e s i a d i f f o r m i s TL.) Aresch. Common s e c o n d a r y / f u g i t i v e  Ag.  species:  Ceramium pac i f icum ( C o l l . ) K y i . Cladophora columbiana C o l l . Cladophora s e r i c e a (Huds.) Kutz. Cladophora stimpsoni i Harv. C o r a l l i n a V a n c o u v e r i e n s i s Yendo ** Endocladia muricata (Post. & Rupr.) J . Halosaccion americanum Lee * I r i d a e a cornucopiae Post. & Rupr. M i c r o c l a d i a b o r e a l i s Rupr. * Neorhodomela l a r i x ("Turn.) Maruda * Pelvet i o p s i s 1imi t a t a Gardn. P o l y s i p h o n i a b r o d i a e i ( D i l l w . ) Spreng. P o l y s i p h o n i a hendryi Gardn. * Ulva f e n e s t r a t a Post. & Rupr. * Rare s p e c i e s : Phaeophyta: A l a r i a sp. A n a l i p u s japonicus (Harv.) Wynne Colpomenia b u l l o s a (Saund.) Yamada C o s t a r i a c o s t a t a (C. Ag.) Saunders Desmerestia v i r i d i s (Mull.) Lamour. E q r e g i a menziessi i (Turn.) Aresch. M a c r o c y s t i s i n t e q r i f o l i a Bory P o s t e l s i a palmaeformis Rupr. Sargassum muticum (Yendo) Fensh. Scytosiphon lomentaria (Lyngb.) J . Ag. Soranthera u l v o i d e a Post. & Rupr.  Ag.  *  49 Chlorophyta: Codium f r a g i l e ( S u r . ) Enteromorpha sp.  Harv.  Rhodophyta: A h n f e l t i a g i g a r t i n o i d e s J . Ag. B o s s i e l l a o r b i g n i a n a (Dec.) S i l v a C a l l i t h a m n i o n pikeanum H a r v . * Ceramium e a t o n i a n u m ( F a r l . ) D e T o n i C o r a l l i n a o f f i c i n a l i s L. C r y p t o n e m i a o b o v a t a J . Ag. Cryptonemia o v a f o l i a K y i . Cumogloea a n d e r s o n i i ( F a r l . ) S. & G. * G a s t r o c l o n i u m s u b a r t i c u l a t u m (Turn.) K u t z . = G^ c o u l t e r i ( H a r v . ) K y i . G e l i d i u m sp. G i g a r t i n a c o r y m b i f e r a ( K u t z . ) J . Ag. G i g a r t i n a p a p i l l a t a (C. Ag.) J . Ag. * Grateloupia setchelli i Kyi. Gymnogongrus p l a t y p h y l l u s G a r d n . Hymenena s p . I r i d a e a f l a c e i d a ( S . & G.) S i l v a I r i d a e a h e t e r o c a r p a P o s t . & Rupr. * L o m e n t a r i a h a k o d a t e n s i s Yendo M i c r o c l a d i a c o u l t e r i Harv. Nemalion h e l m i n t h o i d e s ( V e i l . ) B a t t . O d o n t h a l i a f l o c c o s a ("Isp. ) F a l k . * Odonthalia washingtoniensis K y i . * Plocarnium s p . Porphyra sp. P r i o n i t i s l a n c e o l a t a (Harv.) Harv. P r i o n i t i s l y a l l i i Harv. * P t e r o s i p h o n i a b i p i n n a t a ( P o s t . & Rupr.) F a l k . Rhodoglossum a f f i n e ( H a r v . ) K y i . Rhodomela l y c o p o d i o i d e s ( L . ) C. Ag. Schizymenia sp. /"  Note:  * fugitive species **obligate understory species as p e r D a y t o n (1975)  Table 6  Combined  (total)  each zone at  SITE:  algal  the study  standing sites  HAINES  crop  [ g d r y wt m-2;  averaged over  (std.  dev.)]  the e n t i r e study  HELBY  WIZARD  for  period.  NUDIBRANCH  ZONE I  1019 .6 (567 .7)  433 . 2 (386 .0)  509 .0 (394 .2)  162 . 2 ( 166 .0)  II  640..0 (558 ..0)  625 . 7 (402 .4)  600 .0 (429 . 2)  288 .6 ( 2 1 0 ..9)  III  288 ..5 ( 3 3 0 . 1)  239 .6 (236 .. 1)  4 1 0 ..2 (338 . 2)  532 . 5 (359 . 4)  O  Table 7  Analysis  of  variance for at  SUM OF  SOURCE  Si t e Zone Si t e * Z o n e Month S i te*Month Zone*Month S*Z*M Res i dua1 Total  Note:  SQUARES  1 . 1361E+05 74030 1.7686E+05 1.6386E+05 36323 25037 36658 6.7048E+05 ' 1.2430E+06  Zone mean s q u a r e  combined a l g a l each study  DF  3 2 6 9 25 16 46 1417 1524  tested against  MEAN  Site+Zone  crop  (g  dry  wt  m-2)  site.  SQUARE  37869 37015 29476 18207 1452.9 1564 . 8 796.91 473 . 17  standing  F-RATIO  80.034 1.2558 62 . 295 38.479 3.0706 3.3070 1.6842  mean s q u a r e  •PROBABILITY  0.00000 0.35029 0.00000 0.00000 0.00000 0.00001 0.00309  (fixed-effects  ** ns ** ** ** ** ns  model)  52 The  months  summer  can a l s o  1982  >  Further done  using  pattern Based  fall  S-N-K  N-K  over  very into three  t h e two-way one-way  analysis,  the following  Zone  II >  Wizard:  Zone  I,II >  Nudibranch:  Zone  III >  time.  Zone  I was  (p<0.0l), present  groups,  showed  i n both The  which  more  terms  was  site,  the  differed.  Zone I I I  I >  Zone I I I  Zone  Zone Zone  into  seven  I,III II >  of  f o r Zone  generally  Zone  I  standing  two  ( i . e.  found:  II >  different  groups  data  zones  Zone  divided  however  each  1982-83  p a t t e r n s were  Helby:  zone  At  over  I >  each  > winter  interaction  ANOVAs.  biomass d i s t r i b u t i o n  homogeneous).  groups  by  S-  the t e n "sample the groups  II were  can  crop  be  were  segregated reduced  to  groups:  summer  For  of  groups:  1983  Zone  were  five  three  Haines:  analysis  months"  into  1982,spring/summer  the respective  Likewise, levels  divided  analysis  of a l g a l  on  be  1982,1983  Zone  generally  III,  >  fall  the  g r e a t e r than  1982,spring  summer that  1982 of  1983  algal  the rest  > winter  1982-83  standing  of the study  crop  was  period.  53 At algal were  Haines standing  no w i n t e r  Wizard, of  the  (S-N-K A  1982-1983  data  algal  months.  fall  1982  There to  regression  total  environmental analysis  algal  factors  factors,  previous  are  partial  was  presented  are  23.8-33.9%  of the observed  the  minimum  both  A)  Water  Table  quite  temperature,  + maximum  wave  percent exposure  stepwise;  Results  on  of  ten this  of the factors  values  f o r the  The MULTIPLE-R a n d  for  the  low a n d t h e e q u a t i o n s variance  that  two s i t e s  2  8.  and  grouping  ( g d r y wt i r r )  measurements  coefficients  equations  a t these  months  there  than  (backward,  crop  in  A t Helby  differential  performed.  in  that  was g r e a t e r  analysis  standing  change  be n o t e d  1983 d a t a  (antecedent)  correlation  crop.  crop  was l i t t l e  f o r a) contemporaneous  b) t h e  little  for Nudibranch.  spring  multiple  was  i tshould  standing  p<0.01).  of  there  however,  analysis,  MIDAS)  and  crop;  t h e summer  the other  of  and Nudibranch,  account  in total time  algal  exposed  rating  regression  were  for  only  standing  t o a i r , and present  in  equations.  Abundant  Fucus higher  zones  and  II  also  present  Perennial  Species  distichus a t each  standing site.  are presented i n Zone  Standing  in Figures  i l l of  crop  the  was crop  6a-d.  greatest  data Fucus  sheltered  in  f o r Zones distichus  sites  the I was  buti t s  T a b l e 8.  Multiple at  a)  Contemporaneous  SOURCE R e g r e s s i on Error Total MULTIPLE  regression  all  sites  and z o n e s  DF  SUM OF SOUARES  5 102 107  3.5122E+06 6 . 8458E+06 1.0358E+07 SE  = 578 .8  - 28.4(PFD)  on s e l e c t e d a b i o t i c  crop  (g  environmental  dry  wt  m-2)  factors.  MEAN SOUARE  F-RATIO  PROBABILITY  7.0245E+05 671 16  10.466  0.0000  **  - 0 . .34465 0. 19571 - 0 . 21076 - 0 . 40426 0. 32772  (P (P (P (P (P  =0. . 0 0 0 3 ) =0. . 0 4 6 5 ) =0. . 0 3 1 7 ) = 0.. 0 0 0 0 ) =0. . 0 0 0 7 )  DF  SUM OF SQUARES  R e g r e s s i on Error Total  3 92 95  1 .. 9968E+06 6 ,3794E+o6 . 8 . 3762E+06  R  partial  =  + 61.6(H20-T)  -  0., 5 ( R A I N )  -  54 .0(WAVE  0.48825  SE  =  MEAN  SQUARE  +  6.6560E+05 6934 1  F-RATIO  PROBABILITYY  9.5989  0.OOOO  263.33  correlation coefficients:  Water T e m p e r a t u r e (*C) M i n + Max Wave E x p o s u r e Time Exposed t o A i r (%)  0.20626 -0.33691 0.28625  (P=0.0461) (P=0.0009) (P=0.0052)  VHIb:  Standing  EXP)  variables  SOURCE  EQUATION  standing  Villa:  Antecedent  MULTIPLE  algal  correlation coefficients:  S t a n d i ng C r o p  b)  total  = 259.07  PFD ( u E I N m-2 d a y - 1 ) Water T e m p e r a t u r e ( ' C ) Ra i n f a l 1 (mm) M i n + Max Wave E x p o s u r e Time Exposed to A i r (%) EQUATION  of  var iables  R = 0.58231  partial  analyses  Crop  = 265.59 + 21.0(H2D-T)  -  47.2(WAVE  EXP)  + 2.9(AIR  EXP)  **  55 distribution site,  the winter  The biomass  over  Fucus  the  At  each  decreases  of  F^ d i st ichus  I and I I ) , and time t h e ANOVA  for total  were  the  i s not surprising, three  standing  Averaged  crop  over  sheltered  decreased  zones  resolved  are algal  Zone  and  a s most o f sites  was  with  increasing  and time,  the following  S-N-K  analysis  by  g d r y wt m~ ) : 2  (820.5) >  It  sheltered  also  smaller sites  (532.1),Wizard  as  that  three  with  an e x t e n s i v e  F_;_ d i s t i c h u s  general  the plants  compared  and d i d not form the  (527.5) >  (65.8)  be n o t e d  in size  Seasonally, into  > Helby  Nudibranch  should  much  divided  at  was  Haines  were  in  This  seasonal  ANOVA  Zones  As  lower.  6a-d).  n o n - s i g n i f i c a n t terms  di st ichus  pattern  showed  much  .  exposure.  (p<0.0l;  (only  9.  biomass  di st ichus  crop  multi-way  interaction.  algal  biomass  (Figures  a  zone  Table  the only  three-way  of  site,  in  biomass,  wave  and  months  results  presented  F.  patchy  F_^ d i s t i c h u s s t a n d i n g  during  the  was  groups  biomass using  at Nudibranch those  at  the  canopy. data S-N-K  can  be  analysis  (p<0.01>:  summer  1982 > s p r i n g / s u m m e r  1983 > f a l l  1982,winter  1982-83  Figure 6  Mean  standing  crop  ( + or - one  standard  d e v i a t i o n ) of Fucus d i s t i c h u s i n Zones I and I I at each  study  site  for  each "sample month".  A) Haines B)  Helby  C)  Wizard  D) Nudibranch  •  = Zone I  • = Zone I I  (Zone 1 o n l y )  Month  1600  1200-  •o  800  O) CO  3  o  a u.  400 -  88  Jn  -I  A  1  S  i l ln 1  N  I  8 3  Ja  M  i  Ap  My  }  r  Jn  Month  00  -1  1  1  r——i  1  1  1  1  Jn  A  S  N  Ja M Month  Ap  My  Jn  83  r  A  D - Nudibranch  ^-i  Jn  1  A  1  S  1—ir>  N  Ja  1  M  i  Ap  1  My  1  Jn  r  A  Month o  Table  9  Analysis  of  v a r i a n c e of i n Zones  SOURCE  SUM OF SQUARES  Si t e Zone S i te*Zone Month S i te*Month Zone*Month S*Z*M Res i dua1 Total  Note:  8 .4501E+07 1 .9192E+06 1 .2S64E+07 3..2852E+07 1 .0136E+07 . 4 .1359E+06 . 5 .9770E+06 . 1 .3496E+08 . 2 . 7418E+08  Zone mean s q u a r e  Fucus di st ichus I  DF  3 1 3 9 25 9 25 995 1070  tested against  and  II  MEAN  at  each study  SQUARE  2 .8167E+07 1 .9192E+06 4 . 2212E+06 3 .6502E+06 4 .0545E+05 . 4 .5945E+05 . 2 .3908E+05 . 1 .3565E+05 .  Site*Zone  standing  crop  (g  d r y wt  m-2)  site.  F-RATIO  207.64 0.4547 31.118 29.908 2 .9889 3.3877 1.7624  mean s q u a r e  (fixed  PROBABILIT'  0.0 ** 0. 54844ns 0.00000** 0.00000** 0.00000** 0.00000** 0.01199ns  effects  model)  62 The as  lower  distichus  compared  with  Analysis seasonal than F.  of  observed  large  at  group  Haines  t h e summer by  1982-83,  S-N-K and  showed  i n Zone  the  i n Zone  decreases  II at each  standing  6a-d.  that  homogeneous of winter  1983  site  crop  in  I in  but  no  Zone  I  6a).  site;  site.  and N u d i b r a n c h ,  Wizard,  the result  seasonal  Haines  more  t h e summer in Figures  interaction  was  crop  a t each  at each  during  i s evident  F_;_ d i s t i c h u s  (see Figure  Significant  varied  was  standing  in the winter  Haines  were  This  crop  1982  the Zone*Month  II.  distichus  at  t h e summer  biomass d i s t r i b u t i o n  i n Zone  decline  standing  changes  i n F\  however,  the  There but  was  small  1982  data  analysis  spring/summer  degree  relatively  the  and  distichus  standing at  were  1983  crop  The  periods  change a t always  At Helby  into fall  were  change  was  Nudibranch.  (p<0.0O.  of  little  separated  biomass  a  distinct  1982,  less  and  winter  distinctly  segregated. Analysis significant but  than  that  (F=1.1684  1,300df;  Fj_ d i s t i c h u s i n Zone  irr , 2  in Helby,  Nudibranch,  Zone*Site between  Averaged crops  the  differences  Wizard  Nudibranch,  of  over  Zone  0  I I ; the reverse the e n t i r e  g  g d r y wt dry  wt  crop was  study  site irr , 2  irr . 2  I and  At Haines  i n Zone true  at  I was  were:  Haines,  Wizard,  245.0  site and  greater  Helby.  period,  In each  showed  II a t every  P=0.28061ns).  standing  I I I at each  159.4  Zones  interaction  the  standing  90.1  g d r y wt  g d r y wt  case,  the  nr , 2  standard  63 deviation biomass  exceeded  i n Zone  Analysis month  showed  produced  I I I was  two r e l a t i v e l y over  time  (200-285  during  the other  g  was  over  the  statistical  at  —  are  not  t h e mean  over  site  thus  but the  over  time  the changes i n  true  significant  during  the  summer  wt n r ) was  much  g r e a t e r than  (70-140  dry  wt  site  g  produced  two  and  (F=1.8516  (p<0.0l)  biomass 2  each  I and I I .  not. significant  groups  >  distichus  differences,  similar  Wizard,Helby  crops  III data  analyses  dry  Fucus  i n Zones  S-N-K  months  (p<0.0l)  Standing  that  and month  probably  However,  months  analysis  site  interaction  differences.  than  o f v a r i a n c e o f t h e Zone  P=0.03073ns).  biomass  standing crop.  lower  significant  Site*Month 14,334df;  t h e mean  irr ) .  that S-N-K  2  groups:  Helby,Haines  site  significance  were  also  highly  variable,  of the between-site  so  differences  is questionable. Results F.  distichus  factors air  are  almost  standing  multiple  presented were  twice  crop  MULTIPLE-R  the  standing crop  exposure  were  in  of  on s e l e c t e d  in Table  significant, those  regression  and p a r t i a l  the F^ d i s t i c h u s  regression  10.  analysis  abiotic Both  environmental  wave  exposure  but the c o e f f i c i e n t s  f o r these  factors  (Tables 8 and  correlation  coefficients  but  the  and  f o r each  i n the t o t a l  equations  regressions,  of  algal  10).  The  were  higher  equations  still  64 accounted in  for  less  ¥\_ d i s t i c h u s To  with  in  area, larger  some  and  was  11).  to  were  regression  coefficients, Mean  crop  the  separate  of  the  the  the  equations then  crop  higher  have  in  each  (Table  correlation  factors  present  magnitudes  Hedophyllum  by  month)  in  would  standing  with  the  throughout  regression analysis  and  presented  variations  by  regression  which  However,  is  seasonal  variance  of  in  their  greatly.  biomass  P=0.09470ns).  the  caused  crop  obtain  equations  7,90df;  of  "noise"  F\_ d i s t i c h u s  equations,  Nudibranch  (50%)  standing  obtained.  monthly  (standing  a  differed  cent  coefficients  value,  Regression  the  of  perhaps  correlation  coefficients  at  some  thus  subjected  per  crop.  distichus  predictive  zone  fifty  standing  eliminate  variability study  than  in Figure  was  Thus, the  not  7.  A  in  were  crop  Zone  one-way  significant  there  standing  sessile  no  III  ANOVA  (F=1.8110 significant  of  H_j_  there  are  sessile  at  Nudibranch. It  should  December year, Thus,  1982  in  to March  might these  statistically Evidence H.  noted,  terms  one  during  be  sessile  that  of  however,  1983. wave  expect  a  of  Nudibranch  at in  change  1982-83 comes  no  data  "roughest"  Nudibranch  might  seasonal  winter at  i s the  decrease which  significant  biomass  This action,  months,  the  that  1L  (Table  sessile  then  result  in standing did from  time  indeed the  for of 1).  biomass in  a  crop. reduce growth  Figure 7  Mean s t a n d i n g crop deviation) in  Zone  of III  (• + & - 1 s t a n d a r d  Hedophyllum  sessile  a t Nudibranch f o r each  "sample  month."  1400  E t  1000-  T3  01  Month  Table  Multiple  10.  at  Contemporaneous SOURCE Regression Error Total MULTIPLE  all  sites  analyses and zones  of  Fucus  d i st ichus  on s e l e c t e d a b i o t i c  standing  crop  (g d r y wt m-2)  environmental  factors.  var i ables DF  SUM OF SOUARES  4 103 107  6.9425E+06 6.8640E+06 1.3807E+07  R = 0.70911  partial  regression  MEAN SQUARE  F-RATIO  PROBABILITY  1.7356E+06 66641  26 .045  0.0000  **  SE = 2 5 8 . 1 5  correlation coefficients: PFD (uE i n m-2 d a y - 1 ) Water T e m p e r a t u r e ( * C ) M i n + Max Wave E x p o s u r e Time E x p o s e d t o A i r (%)  -0.29984 0.30627 -0.60717 0.53581  (P=0.0019) (P=0.0015) (P=0.0000) (P=0.0000)  EQUATION X a : Standing  Antecedent  Crop  = -3.3788  - 22.8(PFD)  + 80.3(H20-T)  EXP) + 6 . 0 ( A I R  EXP)  variables  SOURCE  DF  SUM OF SQUARES  MEAN  R e g r e s s i on Error Total  3 92 95  5.3205E+06 5.6725e+06 1.0993E+07  1.7735E+06 61657  MULTIPLE  - 9 3 . 2 (WAVE  R = 0.69569  partial  SQUARE  F-RATIO  PROBABILITY  28.763  O.0000  **  SE = 248.31  correlation coefficients: M i n + Max Wave E x p o s u r e S a l i n i t y (g k g - 1 ) T i m e E x p o s e d t o A i r (%)  -0.55784 -0.23492 0.53224  (P=0.0000) (P=0.0227) (P=0.0000)  EQUATION X b : 0> Standing  Crop  1198.4  - 72.8(WAVE  EXP) - 2 8 . 1 ( S A L )  + 5.8(AIR  EXP)  Table  11.  Multiple  regression for  ZONE a)  I  (all  Antecedent Standing  a)  11  Crop = 611.8  Crop  Antecedent Standing  a)  III  Crop  Standing  dry  wt  m-2)  factors.  SE  +  127.4(H20-T)  -  136.0(WAVE  EXP)  -  76.8(N03)  + 70.9(AIR  EXP)  = 268.8  108.9(AIR-T SE  VAR)  -  119.2(WAVE  EXP)  -11.7(AIR  EXP)  = 252.4  variabless  = 753.1  -  29.2(PFD)  -  SE  =  + 93.0(H20-T)  -  146.7(H20-T  VAR)  -  0.8(RAIN)  115.0  46.9(N03)  R = 0.80021  SE  =  148.2  Nudibranch) variables  Crop = -460.3  Antecedent  -  R = 0.91524  Contemporaneous  MULTIPLE b)  environmental  (g  Nudibranch)  = 477.2  (excluding  Standing  crop  variables  MULTIPLE  ZONE  67.5(PFD)  R = 0.77660  Contemporaneous  MULTIPLE b)  -  R = 0.77482  ( e x c 1 u d i ng  Standing  e a c h z o n e on s e l e c t e d a b i o t i c  standing  variables  MULTIPLE  ZONE  Fucus di st ichus  variables  Crop = -679.4  MULTIPLE b)  of  sj_tes)  Contemporaneous Standing  analyses  + 35.4(H20-T)  R = 0.65000  SE  + 45.0(WAVE  EXP)  = 93.5  variables  Crop = 842.7  MULTIPLE  + 23.0(PFD)  R = 0.87209  SE  + 38.9(WAVE  = 64.0  EXP)  + 62.1(N03)  -  63.5(SAL)  + 20.4(AIR  EXP) CO  69 experiments two  (2)  performed  of  sixteen  survived  into  May  holdfast  with  about  In  1)  was  of  still  irr ; 2  CV  =  for  B)  g  The  dry  June  (  Abundant  n r  wt  Annual  two  III  were  also  only  in  Neither  2  )  was  also  about  1982  of  (558.8  the  the  tissue.  most  abundant  i t s  407.6  ±  abundance  377.2  very  moist were  areas present  crop data  in  dry  g  dry  wt  t o August  mean nr  2  Figure  Leathesia  and  were  wt  1983  standing crop  ) .  i n Zone  II  (shallow i n any  8a).  These these  d i fformi s  and  8a-c  for  Both  abundant  at  sites,  and  at  species  in  but etc.).  Nudibranch. C_^ w o o d i i  (biomass  1982  and  macroalgae  depressions,  abundance  in Figures Yendo  of  d i fformi s most  Wizard.  for  presented  Vancouveriens is  shown  g  the  J . Ag.,  Helby,  sporadically  are  f o r March of  interest,  found  1983  55%  ( J . Ag.)  Haines,  species  Corallina  of  thallus  Nudibranch, =  1982  mentioned:  was  mean  Only  Species  species  at  Standing during  sessile  III at  consisted  eroded  s h o u l d be  6).  i n Sepetember  plants  standing crop  C r y p t o s iphon i a woodi i Zone  tagged  heavily  overall  mean  t o November  The  H_^  (see Chapter  92.5%); 2)  (304.7  of  i n Zone  patchy  these  points  Although  plants  plants  and  5 cm  two  algae  these  (16)  1983,  addition,  species  on  data  Haines behaved  for are as  70 spring/summer crop  annuals,  differed.  greatest peaked  in  At Helby mid-May  a month  Haines,  but C o r a l l i n a  crop  reached  i t may a  by J u l y  significant  for  14,-132df;  differences (F=5.8925  T h e week  Cryptosiphonia  was  8 g d r y wt n r to  2  )at  "replace"  in  ANOVA was  on  i n C_^ w o o d i i b i o m a s s P=0.00025).  that over S-N-K  two d i s t i n c t  ( 1 6 May  the  interaction  analysis  showed  and  performed;  Site*Week  biomass  year), 2  two-way  1983  of  this  the  only  time  were  analysis groups:  1 9 8 3 ; 116.1  d r y wt n r ) ;  Peak  mid-June  the  g d r y wt r r r ) ,  Further  produced  i n March  in  and Wizard  the  o f maximum 2  weeks  difformis  1983.  observed  A  ANOVAs  data  A l l other  Leathesia  was  6,35df;  of the Wizard  2)  recorded  crop  (40-116  Helby,  one-way  g  May  standing  earlier  P=0.00015).  significant  1)  i n May  term  using  early  difformis  first  present  Haines,  interaction  (p<0.0l)  was  than  (Figures 8b,c).  the  (F = 3 . 3 0 9 3  been  biomass  data  Wizard  less  w o o d i i was  biomass  at  biomass  Vancouveriens i s appeared  have  peak  disappeared  only  woodi i  8b,c).  always  standing  site.  Cryptosiphonia (although  p e r i o d o f peak  and  (Figures  (standing  at this  their  and Wizard,  1983  later  scarce  it  however  tested.  was  first  standing (96-130  observed  crop  of  in late this  April-  alga  was  g d r y wt rn" ) a n d r e m a i n e d a t 2  71  Figure 8  Mean s t a n d i n g  crops of L e a t h e s i a  Cryptosiphonia  woodii,  Vancouveriensis  at each semi-weekly sample  time  i n Zone I I I  Wizard d u r i n g  at  and  difformis,  Haines,  Corallina  Helby,  and  the s p r i n g and summer of 1982 and 1983.  A) Haines B) Wizard C) Helby  •  =  difformis  •  = Cj_ v a n c o u v e r i e n s i s  •  = C. woodii  Month  74 fairly  high  8a-c). crop L.  levels  The  in  results  1982  and  difformis  (as  would  be  was  of  at  than  that  Wizard.  and  within-site  lack  abundances  deviation).  The  results  of  d i f f o r m i s and  analyses  were  and i n any  the  1983.  Further  showed  that  standing  not  at  Helby  14,  significant  at was  probably of  due  crop,  was  greater  than  significant to  difformis  standing  crop  to  the  only  are  Larger were  data areas  abundance).  for  the  highly  ( i . e . mean  where  for  presented  in  MULTIPLE-R  and  obtained Zone  in  Haines  statistically  coefficients  (the  standing  in turn  respectively.  restricted  significant  multiple regression analyses  woodi i  Wizard  Site*Week  but  biomass  which  was  standard  correlation  time  The  difformis  difformis  of  than  partial  years,  over  ANOVAs  in  standing  both  statistically  in L^  differences  and  In  during  Wizard,  no  Helby,  The  13  12.  species).  one-way  changes  were  at  variable  found  annual  with  difformis  significantly  di fformis  that  Tables  in Table  (Figures  P=0.01185ns).  site  Helby  an  declining  for L^  varied  Haines  between  L.  ANOVAs  significant  1983  greater  less  of  differences  and  at  crop  there  between-site  before  shown  term  11,54df;  1982  are  significant  Although  both  month the  also  this  occurred  (F=2.5300  1983  expected  statistically crop  of  standing  interaction analysis  for a  III  these  when at  the  Haines,  plants  were  Table  12.  Analysis in  SOURCE  of  Zone  v a r i a n c e of III  SUM OF SQUARES  at  Leathes i a di fformi s  Haines,  DF  Helby,  MEAN  and W i z a r d  SQUARE  standing for  crop  1982 a n d  (g  dry  PROBABILITY  0.02849 O.OOOOO 0.18655  30518 3.7076E+05 68G44 3.9660E+05 8.7435E+05  2 7 12 96 117  15259 52966 5720.3 4131 .2  3.6936 12.821 1.3847  1983 : Si t e Week S i te*Week Res i d u a l Total  16787 1.5326E+05 1.3245R+05 4.0052E+05 7.0129E+05  2 1 1 18 159 190  8393.3 13932 7358.2 2519.0  3.3320 5.5310 2.921 1  m-2)  1983.  F-RATIO  1982: Si t e Week Si te*Week Res i d u a l Total  wt  0.03823 0.00000 0.00017  ns ** ns  ns ** **  Ul  Table  13.  Multiple (g  A11  5i tes a)  regression  dry  a n d Al1  wt m-2)  Crop  Antecedent Standing  a)  III  at  Crop  = 21.1  Standing  2.7(PFD)  Crop  +  SE  + 6.4(H20-T) =  1.2(PFD)  = 0.46403  Contemporaneous  Antecedent  -  crop  factors.  -  3.9(N03)  -  0.2(AIR  -  0.3(AIR  EXP)  20.3  SE  =  H e l b y and W i z a r d  2.7(H20-T) 13.7  Only  -  7.0(PFD)  = 0.88278  SE  +  16.7(H20-T)  = 22.0  variables  Crop  = 57.7 + 5.9(PFD)  MULTIPLE-R  EXP)  variables  = 114.4  MULTIPLE-R  b)  environmental  standing  variables  Haines,  Standing  on s e l e c t e d a b i o t i c  = 0.53249  MULTIPLE-R  Zone  Leathes i a di fformi s  variables  = 90.0  MULTIPLE-R  b)  of  Zones  Contemporaneous Standing  analysis  = 0.66529  SE  =  13.3(H20-T) 22.1  -  26.0(AIR  VAR)  -  11.1(N03)  Table  14.  Multiple crop  A1 1 S i t e s a)  (g  and A11  regression d r y wt m-2)  Crop  Antecedent Standing  a)  III  at  Crop  = 15.1  Contemporaneous Crop  Antecedent Standing  1.7(H20-T) SE  =  + 0.5(PFD)  = 0.42809  Helby  environmental  factors.  -  0.2(RAIN)  -  1.0(SAL)  -  0.1(AIR  EXP)  G.1  SE  =  1.7(H20-T)  and W i z a r d  +  Only  1,2(PFD)  = 0.74364  = 59.3  MULTIPLE-R  EXP)  6.3  SE  -  =  8.7(H20-T)  9.4  variables  Crop  - 0.1(AIR  variables  = 188.6  MULTIPLE-R  b)  on s e l e c t e d a b i o t i c  standing  variables  Ha i n e s ,  Standing  -  = 0.49210  MULTIPLE-R  Zone  C r y p t o s i p h o n i a wood i i  variables  = 57.5  MULTIPLE-R  b)  of  Zones  Contemporaneous Standing  analysis  + 2.1(PFD)  = 0.67647  SE  =  7.7(H20-T) 10.2  - 0.1(RAIN)  -  3.1(SAL)  78 C)  Common  Secondary  Those  intertidal  secondary  species"  distributed At  the  canopy.  of  then  three  restricted  Zone  the  "algal  macroalgae  were  tests  were  a .species  common performed showed  crops  were  also  Zone  II  species  significant  I  and  generally less  levels  cornucopiae  not  seasonal  1imitata,  Zones  up  a  ( e . g.  of  these  (1975)  as  either  (see Table 5). crop  data  A n a l y s i s of variance  zones  at each  sporadic  or  site  where  infrequent  s p r i n g o r summer m a x i m a i n every  species  showed  changes.  cornucopiae  muricata Post.  II a t Nudibranch. 10 g d r y  t o 29 g d r y wt m~  showed  crops i n  Most  species  Endocladia  than  Fucus  components  of the standing  showed  although  standing  Nudibranch  Dayton  species.  generally the  important at  patchily species".  were  under  spp.).  by  than  species  areas  f o r those  J . Ag., and I r i d a e a  biomass I.  only  "common  a n d more  had l a r g e r  a summary  more  Each crop,  in  to  a n d were  secondary  Pelvetiopsis  common  these  species  classified  as  perennial/annual  Polysiphonia  15 p r e s e n t s  statistically  Rupr.)  abundant  II  of  classified  or " o b l i g a t e understory"  occurrence. standing  and  turf"  spp.,  these  I  sites  Cladophora  Table  less  "abundant  of these  I I I of these  for  were  i n Zones  "fugitive"  macroalgae  sheltered sites,  Some  the  Species  statistically  2  wt were  &  (Post. & Rupr.  Their irr  2  ,  were  standing but  recorded.  significant  peak Only zonal  T a b l e  1 5 .  S u m m a r y  o f  s t a n d i n g  v a r i a n c e  p a c * f i  c u m  r t  d a t a  h  A  8  H  19  W Vancouver  i e n s i s  2  o n  i c a t a  e  a )  7  n s (  a m e r i c a n u m  A  15  8  N  B9  5  3  A  16 7  I_.  c o r n u c o p  e  o n l  b o r e a l i s  N ,  P  I  .  a  n  8  2  1 u r n t a t a  P o i y s i p h o n i  U.  f e n e s  se  A  a  s p p  t r a t a  2  1  U  5 5  3  J 4  8  J 1  o v e r a A » H A  ( 2 )  1 1 J N E  2  v a lu e s s e a s o n  10  5  12  1  H  8  'n  n o  (  )  < 3 >  n s  -  ( 4 )  n s  -  ( 5 )  s i g n i f i c a n t  1  1 8 - 5 2 1  IW  1 7 - 2 5 1  ( N  2 1 - 2 6 1  8 3  3  -  ( 6 7 1  n s  8 2  s o r i n g  8 3 ( 2 2 9 1  1 2 7 3 1  s u m m e r  s u m m e r  :  8  v  n s  1 7 - 1 0 1  1 18 - 2 J 1  8 3  -  s u m m e r  S u m m e r  0  n s  1  J  5)  3 : 1 2  n s  c r o p  (  ( 1 : 2 1 1  a  r  i  s t h a t  e m a x im u m  n s  s u m m e r  -  s p r , n g  -  (2 2 - 2 3 I  ( 1 0 1 - U 3 I  8 2  ( 1 0 5 1  8 3  1 2 6 - 2 9 1  8 2 / s p r m g  s o  r  i n g  8 3  (13  8 3  (18  1  r  y w t  m  (3 351 ( 1 6 - 2 2 I  ')  N = N U D 1 B R A N C H  o f  5 l a n o  m a x i m u m  d i f f e r e n c e s  m  n o  s i g n i f i c a n t  d i f f e r e n c e s  n o  s i g n i f i c a n t  d i f f e r e n c e s i  8 2  S u m m e r  s i g n i f i c a n t  d i f f e r e n c e s  8 2 8 3  Summer 82 I 2 2C I  7  r e c c o e d  p e r i o d  s u m m e r s p r , n g  S u m m e r  J  g d  -  n s  o n l y  W - W I Z A R D .  -  S u m m e r  o n l y  2  (39-60 1  8 2  8 2  ( 2 : 1 7 1  3 o n l , -  0  s 1a n d i n g  s t a t e d  -  1  o n l y  2  s e e  H « M E L B T .  n s  o n l y - 1 3  1 o n l ,  N  m e a n S.  g  -  2 \  I  o n l y ( 3  2  I I )  (18  8 2  s u m m e r  n s  i  o n l y  3  N  z o n e <  N o t e s :  m  E I O M A S S f  ( A . 1 3 - 1 3 1  2 : 3 7  1  N  w:  s p r  l o n e  o n l  1  e  7  N  .  3  s e e  z o n e ( 5 M_  y  o f  6  2 6  N  ia e  s u m m e r  I H .  1 * 2  H  -  G B E & T E S T  3 1  2 * 3  5.  N  n s  OF  1  n s ( H .  1 y  a n d a n a i > s e s  s p e e » e s .  1  13  N  m - 2 )  s e c o n d a r y  s u m m e r  n s (  m u r  g d r , w t  5  9  N  E .  l  e c o m m o n  MONTHS  e  3  N  C 1 a d o p h o r a s p p .  C.  c r o p  o  SITE! 1 )  S P E C I E S  C.  f  \n g  c ro p  s t a n d i n g  *r .  g  dr  c r o p  b v  m  s t a n d i n g  c r o p  b e t w e e n  m  s t a n d m g  c r o p  b e t w e e n  n s t a n d i n g  c r o p  b e t w e e n  •,  w 1  m  c r o p  s t a n d i n g  m o n t h  z o n e s  ( A N O V A t s i t e s  ( A N O V A I  ? o n e s  I A N D v f i )  ( A N D V A J  80 (F=6.8391 7,l95df;  dominated  by  biomass  and  2  (maximum  biomass  Halosaccion  fairly  =  spp.,  Significant for  Ulva  7,99df;  (p<0.0l)  7,99df;  Corallina H. a m e r i c a n u m in  Zones  mentioned  II  Analysis in  , N_^ l a r i x , and  III  of  C_^ v a n c o u v e r i e n s i s  (F=7.6327  (see  7,121df;  Post.  based  algal  and  on  crop  ,  Corallina  Polysiphonia fenestrata  S-N-K data  analyses for  Cladophora  Helby  significant  also  these  spp., found  and Wizard. to  III  analysis  As  "replace"  (Figures  seasonal  i n Zone S-N-K  were  seemed  I I I at Haines  crop  were  month.  C^ V a n c o u v e r i e n s i s  P=0.0000).  crops of  biomass  Ulva  However,  Haines,  standing  were  patchily  16),  and l h f e n e s t r a t a  showed  Rupr.,  & Rupr.  standing  Table  the standing  at  Maruda  boreali s  7,99df; P=0.00056),  woodi i i n Zone variance  (Turn.)  generally  in  Vancouver i e n s i s  previously,  Cryptosiphonia  changes  groups  biomass =  turf".  P=0.00003).  distinct  were  was  Cladophora spp.,  (maximum  P=0.00976),  d i d not segregate into  zone  spp.  spp.  (F=5.3553  fenestrata  an " a l g a l  (F=4.0846  (F=2.8358  l a r ix  Microcladia  seasonal  Cladphora  (maximum  Lee,  vancouveriensis  species  (F=8.4272  Nudibranch  2  These s p e c i e s  and formed  at  d r y wt n r ) .  in this  2  distributed  II  g  and  abundant  Zone  Neorhodomela 105  g d r y wt n r ) .  found  seasonal  Vancouveriensis  americanum  Polysiphonia  16-26  in  Corallina  g d r y wt i r r )  also  and  P=0.00000) c h a n g e s i n b i o m a s s .  Macroalgal  272  P=0.00962)  1,l95df;  8a-c).  variation at  Haines (p<0.0D  81 separated time  the A p r i l  of greatest  N.  of  larix  S-N-K  lar  and W i z a r d ,  analysis  crop  found  only  rarely  significant  the months.  III at  both  Helby.  An  i n Zone at  differences  P=0.00737).  d i d not d i v i d e  in  However,  t h e months  into  any  III  in  Halosacc ion  americanum  were  found  Haines  at Wizard.  site,  but  i t s greatest  Zones  III no  Wizard  with  Helby  significant Zone  (F=11.794  and  1,213-df;  III  at  Wizard  (p<0.0l)  the  Wizard,  with  Zone  U^  and  and  Wizard  Zone Zone  from Zone  at III  II a t  crop  in  Nudibranch  f o r Zone  fenestrata  from  not  intertidal  II at  Likewise  Significant at  did  standing  significantly  P=0.00624)  found  (F=3.0149  fenestrata  1,235df; P = 0 . 0 0 0 7 0 ) .  s t a n d i n g c r o p were  i n biomass  development in  differences.  differed  variance  throughout  II at Nudibranch.  I I I of Wizard  (F = 7 . 6 2 9 3  and  C o m p a r i s o n of U^ of  showed  II  found  and  of  analysis  was  showed  analysis  changes  b u t S-N-K  between  H a l o s a c c i o n americanum  An  fenestrata  Nudibranch.  in  7,215df;  Ulva  Helby,  Zone  found  between-site  seasonal  separate  Zone  the  2  occasionally  showed  as  rrr ) .  1,239df; P=0.00001).  P=0.00439),  at  only  Zone  7,239df;  each  also  differences in  (F=19.873  showed  a l l o t h e r months  groups.  standing  was  but  (p<0.0l)  Significant  Helby  was  (F=2.8467  analysis  from  ( 6 7 g d r y wt  ix  variance  biomass  distinct  month  biomass  Neorhodomela Haines  1983  II  at  biomass i n  that  at  II at  Helby Wizard  seasonal changes  (F=3.4994  9,235df;  82 P=0.00044), analysis  however,  (p<0.0l)  Cladophora distributed shows over  of  the  similar.  (F=2.7809  secondary  species".  Cladophora  III.  not  analysis  S-N-K  crop  were  very  interaction  the  16  analysis  showed  o f Zone I  I I (F=6.0181  of the Site*Zone  one-way  ANOVAs (F=6.3543  (F=12.140  2,402df;  P=0.00001)  2,306df;  P=0.00000),  biomass  (S-N-K  III .  Table  9,552df;  once a g a i n months  S-N-K  into  very  at  each  groups.  using  showed  widely  between-site  but they  However,  divide  a t Haines  II  found.  Zone*Month  differences  spp.  most  Significant  were  the  did  S-N-K  spp. standing  three groups,  b u t n o t i n Zone  Further site  the  and months.  of  by  seasonal changes i n the standing crops  (p<0.0l)  distinct  perhaps  9,498df; P=0.00346) a n d Zone  P=0.00000), analysis  for  produced  Analysis  significant  were  differences  by m o n t h  distinguished  similar.  "common  zones,  seasonal  groups  very  results  a l lsites,  (p<0.01)  were spp.  t h e ANOVA  and  the  at  test,  that  but  Wizard  p<0.0l).  Cladophora  interaction  showed  significant  2,434df; P=0.00191),  not  and at  and Nudibranch At Haines,  Nudibranch Helby.  standing crop  Wizard  (F=21.491 Cladophora  was g r e a t e s t  S-N-K  zonal  analysis  was g r e a t e s t  i n Zone (p<0.0) i n Zone  Table  16.  Analysis (g  SOURCE  Note:  21809 40843 56277 86785 68222 49756 1.1383E+05 2.1696E+06 2.6304E+06  Zone mean s q u a r e  variance  d r y wt m-2)  SUM OF SQUARES  Si t e Zone S i te*Zorie Month S i te*Month Zone*Month S*Z*M Res i dua1 Total  of  at  DF  3 2 6 9 25 16 46 1419 1526  tested against  of  C1adophora  each study  Site*Zone  standing  crop  site.  MEAN SQUARE  7269.7 20422 9379.6 9642.8 2728.9 3109.7 2474.6 1529.0  spp.  F-RATIO  PROBABILITY  4.7546 2. 1772 6.1346 6.3067 1.7848 2.0339 1.6185  0.00265 0.19457 0.00000 0.00000 0.01007 0.00905 0.00590  mean s q u a r e  (fixed  effects  ** ns ** ** ns ** **  model)  84 Di s c u s s i o n  Macroalgal  standing  exposure  and season;  between  summer  and  diversity  crop  there  varied  were  also  1982 a n d summer  (see Chapter  with  height,  differences  1983.  5) a l s o  tidal  Species  varied  in  wave  biomass  distributions  along  these  three  effect  on t h e  gradients. Wave  exposure  distribution  and  Significant were  found  varied  between-site  between of  this  study,  also  been  Southward Dayton,  t o have  abundance  (Table  abundance  appeared  7). the  Zonation  in  decreasing  with  noted  other  1976,  macroalgae. standing  crop  composition  also  (Figures  5a-d).  sheltered areas  increasing workers  1954; S t e p h e n s o n  1971; Menge  in algal  and s p e c i e s  sites  F_;_ d i s t i c h u s  and Orton,  intertidal  differences  study  by  of  a major  1978;  wave  The  observed  exposure,  (Burrows  has  e t a l . , 1954;  and Stephenson,  Lewis,  in  1977;  1961b;  Lubchenco,  1 980) . In crop  the  on  MULTIPLE-R relatively species, perennial, each  regression  selected and  abiotic partial  low ( T a b l e with  of t o t a l  environmental correlation  8).  different  competitive  responding  equations  This growth  dominant  differently  algal  standing  factors,  the  coefficients  i s not s u r p r i s i n g , strategies vs f u g i t i v e )  as  are many  ( e . g. a n n u a l were  to the environmental  vs  present,  factors.  85 In  both  exposed  to  analyses,  a i r , and  the  rating  were  negative  coefficient  cent  time  8). prove  the  of  remove  algal  exposed  to  Hardwickeffects  important negative algal Puget with  in  Sound.  negatively  their (Rigg  correlated  Miller,  Widdowson, The  in  vertical  using  1965a;  was  1949;  distribution  of  (Table  on  areas  also  and  and  community  in  correlated  (r=0.62), Thorn,  Druehl  algal  biomass  and  1980). of  the  comparable  with  Pacific  northwest  Stephenson,  1971;  small  time  strongly  the  very  a  heights)  of  time  regression  found  light  to  estuarine  emergence  were  the  significant  was  (r=-0.93;  area  of  an  algal  most  not  abundances.  found  (1980)  (tidal  Stephenson  Dayton,  per  cent  multiple  and  rainfall  in other  while  per  algal  between  (r=0.8l)  Bamfield  strong  disturbance  type  Thorn  abundance  the  a  effect  ( i . e.  intertidal  with  a  also  substratum  low  exposure  support  position  distributions  algae  as  height  (r=-0.33)  a  in  (1983)  and  time  r e g r e s s i o n a n a l y s i s do  intertidal  study.  temperature  distributions and  tidal  abundances  Algal  Vertical intertidal  for  cent  had  positive  (acting  height  correlation  per wave  exposure  evidence  Mathieson  their  maximum  small  the  are  However,  abundance  air  and  algal  techniques.  a  in determining  tidal  on  of  and  the  regression equations  exposure  biomass)  Witman  gradient  they  +  Wave  a i r had  results  wave  air)  of  minimum  i n the  to  causation,  importance  temperature,  significant.  exposed  Although  water  and  Green,  1961a; 1982).  v a r i e d along  the  86 wave  exposure  Nudibranch at  (most  Haines,  observed  Fucus  sites;  (II  III)  and  increased noted  a  standing and  (Table  reduction  abundance  with  Lubchenco  (1980)  found  abundant  addition, species  as  Dayton,  1971  Fucus  in  noted  Fucus  wave  an  wave  distichus  o f 1 kg d r y wt m" .  L.  in  ssp.  northwest edentatus  Spain,  to  those  area. canopy  at the three  Zone  and Stephenson increase  in  on  or  also  sessile  (1971)  and  abundance  fucoids  the  in "fugitive"  exposure  H^  fucoid  increased,  zones  (1961b)  Dayton  in  lower  most  area, 2  reported  for the  I a s wave  the  crop  to those  similar  and  became  shore.  In  "ephemeral"  (see Table  1 i n both  1980).  in  similar  study  abundances  seem  increased  macroalgae levels  the  was  data,  in  cover)  and Lubchenco,  and  i n the lower  exposure  exposure  Stephenson  exposure)  exposure.  increase  that  wave  changes  at  from  increased  and  similar  A s wave  was  algal  an e x t e n s i v e  Stephenson  (per cent  there  Island  crops  increasing  here.  of  and  decreased  6).  different  any q u a n t i t a t i v e  f o r the Bamfield  formed  assemblage  Although  not c o l l e c t  height  study  distichus  sheltered  distinctly  Wizard.  of Vancouver  in this  macroalgal  descriptions  (tidal  coast  The was  did  qualitative  southeast  more  and  (1961b)  distributions  as  exposed)  Helby,  Stephenson their  gradient.  at times  (1977) (1983)  (de l a P y l . ) P o w e l l  species  reaching  The v a l u e s  by N e i l l a n d Thorn  abundant  found  f o r Fucus f o r Fucus  i n Puget  Sound.  of  standing here  are  spiralis distichus Fucoid  87 biomass F.  in  Helgoland  spiralis  Fucus  kg  dry dry  wt wt  Ascophyllum converted  100-500  In  di st ichus  of  values  wt  nr  in  crop  (1983)  similar density factors  factors  neither  are  America and  also  of  is  their also  which 8  in  did and  the  10.  figure Water  a i r temperature  nor  to  the  for  range  estuarine  environmental  factors.  the  daily  In  for  cover  addition, and  a and the the  greatly.  those  environmental  regression was  factors.  values  equations,  differed  temperature the  found  F\_ d i s t i c h u s  F\_ d i s t i c h u s  note  into  and  coefficients  of  MULTIPLE-R  regression  important not  correlation  abiotic  coefficients,  of  Europe.  analyses  environmental  present  levels  and  selected  of  between  Chock  coastal  of  about  (values  ranges  for  low  Nova  dry:fresh  along  and  and  mean  spp.  1977c;  crop  L.  crops  mid-way  regression  reported  a  0.2  biomass  for  of  about  partial  selected  of  2  In  value  Fucus  1976,  rrr  1982).  found  ratio  standing  reported  the on  a  wt  standing  and  fucoid  analysis  on  Tables  using  the  study  North  mean  combined  dry  serratus  (1972a)  regression  magnitudes It  Thus,  this  in  a  (Brinkhuis,  2  kg  Markham,  Lejolis  weight  MULTIPLE-R  standing  in  fresh  throughout  found  the  0.5  Fucus  and  Mann  (L.)  previously  Low  Thorn  for  for  2  reported  and  2  2  irr  (Munda  (1952)  1983).  F.  wt  between  estuarine areas,  dry  Mathieson,  were  L.  nr irr  from  g  dry  nodosum  weight).  areas  kg  MacFarlane  kg  1.6  3  vesiculosus  Scotia, 3.4  and  ranged  equations  significant,  variation  in  air  but or  88 water of  temperature  the latter  showed  a  However, during  while  highly water  summer  crop  summer.  In a d d i t i o n ,  may  less  equations found air  strong  temperature An  (25%) in  i n Puget  crop  that  every  winter  and  analysis  standing showed  time  cover  standing crop o f t h e summer  Mathieson  (1983),  was  during  the  temperatures  These  differences  (1980),  per cent  in  the  however,  cover  and only  temperature  stable  increasing;  stable  Thorn  Sound,  and  small (and  (r=-0.39) and  a i r  (r=-0.33).  Fucus  density  were  also  correlated  with a i r  (Thorn,  seasonal I  at  levels  changes  and  biomass  I  1983).  were  a n d Thorn  in  F^ dist ichus  II of the sheltered decreased  Haines were  1982 l e v e l s .  abundance  relatively  to  Zones  b u t Zone  water  Table I I I ) .  temperature  algal  water  and  exposed  F^ d ist ichus  zone  fucoid  with  for neither  a i r  of water  of water  i n Puget  Sound  of  in  range  a i r temperature.  (r=0.8l)  of  was  relatively  between  significance  (r=0.9l51;  of a i r temperature.  correlations  distichus  also  correlations  amount  However,  a i r temperature  the yearly  that  not  temperature  the  were  of  understood,  temperature  f o r the inclusion and  opposite)  in  levels  than  account  easily  correlated  months,  standing  was  was  The l a c k  seasonal pattern.  were  the  important.  two f a c t o r s  strong  temperature  were  noted (1983).  during  (Figures  about  sites  the winter  6a~c) .  The  twenty-five per cent  Similar  seasonal  by N e i l l  (1977),  changes Chock and  89 While  increased  wave  reduced  di st ichus  is  that  doubtful  (Table  1).  hypothesis  d e c l i n e , perhaps  vigour,  still in  hypothesis, (1979),  based  is  that  submergence during plants  and  the at  does Zone  that  due  not  to  at  have F\  a  the  Schonbeck  seawater  resulted  in and  the  submerged  in  the  1983  to  nitrate the  1  ) ,  ).  cent  nitrate  effects  Haines; survived.  the  high of  i n F\ Zone  the  the  winter  (18.6  during  the  were  of  of  the  found  and  for  Zone  F^  long  II  that  spiralis periods  lower  concentrations  I  was and  at  a  large  Zone  (Table  3;  II  N0  l "  3  spared  Additional experimentation  plants  during 1  ) .  submergence winter  difference  February  Haines  d i s t i c h u s standing  I plants  periods  concentrations  pg-at  increased  Norton  nitrate  there Zone  of  second  and  (1979) Thur.  at  concentration  concentration decline  not  Haines,  time  a i r during  high  but  At  relatively  combined  to  NO^ 1"  the was  at  1  per  exposed Also,  d" )  et  a  concentrations  death  Norton  loss  A  longer  nitrate  when  decayed  Haines  seasonal  Haines.  of  i t  undergo  different  of  and  pg-at  may  work  senesced  (6.6  at  the  Dene,  1  so  on  Schonbeck  NO ^ 1 "  done  at  (L.)  pg-at  Wizard,  II  canaliculata  (33  and  Zone  combination  have  Helby  and  winter  may  post-reproductive  explain  elevated  hours  winter  di st ichus  Pelvetia  (20  the  I  the  Haines.  crop  action could  seasonal  patterns  during  standing  wave  The  action  may  have  crop these  in  1983). January  Thus,  and  were  the  elevated  contributed II  at  conditions  and  i s needed  Zone  to  evaluate  90 this  hypothesis  for  interacting  and  increased In  and  effects  appeared  to  play  community.  Many  of  Cladophora  spp.  and  understory  species  protected  sites.  spp.  community Chapter  was  to  the  of  most  concentrations  the  on  secondary spp.)  of  be  role  F^  also  only of  and  in  of  this  (e.  g.  found  as  the  appeared  more  to  be  abundance  distichus  discussed  in  species" were  distribution  species  F\_ d i s t i c h u s  intertidal  di st ichus  roles will  area,  structural  upper  the  abundant  study  Polysiphonia  in  an of  intertidal  more  detail  and  harmful  found  noted  that  the  the  exposed  absence  effects  of  in  III  in  Zone  after  at  distribution  of  moderate  sessile  sessile  increased  was  siltation  site.  sessile of  wave  sites  (based  sessile  growth  outcompeted (Farl.  Silva. from  this  degrees  f o r H_;_  littoralis  setchelli i of  Nudibranch;  II  removal)  sites,  Hedophyllum  at  "physiologically optimal"  Lessoniopsis  Laminar ia the  to  species,  Zone  also  shores  by  in  were  exposed  sites  perennial  only  recovery  most  attributed the  also  Although  rates  Reinke  "common  abundant  plants  (1975)  action.  these  the  dominant  limited  were  the  important  (the  other  occasional  on  nitrogen  responsible  5).  sessile,  was  the  an  Fucus  structure  The  Dayton  in  in  influence  Littorina  mechanism(s)  elevated  being  macroalgae to  important  of  the  submergence.  addition  intertidal  elucidate  et  Dayton sheltered at  these  at  Setch.) (1975) sites  to  sites  on  91 the  gametophyte.  problem  at Haines  present  in  evidence  of  of  III  there  i n the  winter  (see  Chapter  H.  winter  sessile  significant  thin  may  layer  sites),  have  of  there  been  sand was  a  was little  Wizard. no  significant  crop,  fall  this  may  1982  were  would  be  due  A l l but  to  two  the  of  the  to  survive  the  (1965b)  reported  that  damaging  to  H^  is  particularly note  distributed,  differences  been  failed  However,  differences  have  Widdowson  storms  seasonal  1982-1983.  of  6).  patchily  siltation  these  populations.  relatively  (a  f o r the winter  tagged  and  at  were  plants  fall  at  standing  data  while  Helby  siltation  H_;_ s e s s i l e  lack  and  Zone  Although in  However,  so  that  that  difficult  sessile  statistically to obtain  i n any  case. Mean ranged  H^  sessile  between  standing  crop  spring/summer during 1983.  the  have  and  severe  Widdowson,  L.  725  than  the  g d r y wt  375  g  summer/fall  irr ,  dry  1982,  but  H_;_ s e s s i l e been wave  the  rare  standing  result  action  of  during  while  2  wt  nr  during crop  the  abundant  spring/summer  during  reduced the  also  the  sessi le  during  2  were  PL  1982  1983  recruitment  winter  (see  may, that also  1965b).  Larger were  during  J u v e n i l e sporophytes  summer  therefore,  and  less  1983.  lower  year  450  was  The  biomass  obtained  difformis  MULTIPLE-R when  the  standing  and  partial  correlation  regression analyses crop  were  of  restricted  C\  coefficients woodii  to the data  and for  92 Zone  III  at  discussion equations  will  only  to  each  regression  were  temperature  that  twice  that  Except  antecedent),  the  f o r water There  is  difformis  have  intertidal  areas  1975) the (=  following  the  regression (Equations  been  the  sheltered  In  to  Zone  between  larix) were  Bamfield  and  .  a l .  that  there  nor  larix  distributed  does  not  studies Helby  has  and  studied C.  (Yendo) Zone  of  (1971,  ^(Turn.)  in  and  either  Dayton  (1983)  muticum  of  positive  Haines,  (1968)  Sargassum  reflecting  difformis,  ecological  Rhodomela  light.  i n f o r m a t i o n on  III at  for  equations  twice  were  DeWreede  patchily  Ag.  Fensh., III  at  sites.  observed  v a r i o u s times Puget  et  water  for  (  addition,  previous  Ricketts  (1980)  woodi i a t  12-2b  for light  In  any  similar  plants  Thorn  .  difformis  Neorhodomela  about  ecological  woodi i  those  L_^_ d i f f o r m i s  was  Equation  and  coefficients  woodi i e q u a t i o n s ,  biomass  little  (PFD)  (2-3x)  very  interactions  these  the  for  the  negative.  mention  study.  The  data  light  temperature  Neither  but  C.  to  III  i n the  coefficients  or  to  Wizard.  of  difformis  woodi i .  appear  Zone  times  about  L.  the  two-to-three  were  those  limited  with  coefficients  C.  be  significant,  respective  fact  Wizard.  equation,  The  the  and  13-2ab).  temperature water  Helby  therefore  pertaining  12-2ab and In  Haines,  Sound,  low of  the  Hurd  (<4.9%  cover)  year  during  (1917)  found  abundances a  two  of  year  tetrasporic,  93 carposporic R.  and "young"  E . Foreman  (unpublished  December  to  Georgia.  Maximum  slightly  lower  C.  on  but o n l y  tubes.  on a  of  Nova  was  ( 3 8 . 8 g d r y wt Scotia,  t h e demography  observed  in early  standing  Thus, in  crop,  Scotia  Chapman mortality  in  they  only  "exposed and  as compared  mortality one  t o heavy  wave  Goudey  increased  increase used  i s about  and  to  i n mid-July,  action  twenty with  Barkley  (1983)  with  that  much  during  Great  1958).  In data) As  Strait  of  in Bamfield. recently was  first  mid-September.  5.5  g d r y wt n r  (20x) l e s s  2  .  abundant  Sound.  attributed They  which  throughout  in  have  difformis  also  i n c r e a s e d wave  site  increased  the  into  times  May  epiphytic  The a l g a  about  crowding.  study  surf  was  Thus,  and October.  (1983)  survived  was  during  i t was  in  d ifformis.  and  study.  biomass  than  Goudey  of  June  difformis  Nova  and  which  (unpublished  crop less  2  Chapman  studied  Peak  n r ) was  ,  of  annual.  February  standing  2  (Conover,  E. Foreman  between  maximum  n r  where  i n June  from  i n the S t r a i t  difformis  shore  February.  plants  this  difformis  R.  JJ^ difformiS  in  finding  noted  Georgia,  location  spring/summer  sandy  to  collected  found  strict  December  2 3 . 5 g d r y wt  T h e maximum  C_^ w o o d i i ,  Georgia  was  reported  Massachusetts  collected  data)  that  n o t be a  June,  Strait  with  than  from  subtidal  biomass  (1969)  worm  the  at a  Harlin  Pond,  In  August  w o o d i i may  and  C. w o o d i i  they  noted  action,  however  described  of the study the  an  summer.  as  period", While  94 L.  difformis  Bamfield, Nova  was o n l y  i t  was  Scotia.  difference coasts.  abundant  apparently  This  in  may  di fformis  standing  L.  di fformis  biomass  exposure  gradient  The  "common  distributed (e.  g.  otherwise  these  species  in  Markham, but  species Spain  1982)  much g r e a t e r  (1983)  f o r a New  Because difficult  at  were  with  ).  comparable  a New  England  than  those  reported  physical  (such  the  sporadic  to  ,  Helgoland  Halosaccion crop  levels  for similar (Munda  (Conover,  by C h o c k  in  occurrences  those  estuary  area  and  and 1958),  Mathieson  estuary.  relatively  patchy  almost  conditions,  presence  widely  abundances  distributions,  t o make a n y c o n c l u s i o n s c o n c e r n i n g  particular  wave  and the study  The s t a n d i n g  and  species are  Bamfield,  either  Vancouveriensis  1977),  Hampshire  t h e two  differences in  maximum  (Neill,  of t h e i r  Some o f t h e s e  as  were  great  the increasing  intertidal  larix  the  Nudibranch.  times,  Corallina  , Neorhodomela  to  along  at  site in  between  found  o r showed  and/or  crop  species"  the  spp.),  areas ( e . g.  americanum for  secondary  Cladophora  particular  were  Haines  throughout  explain  between-site  d i d decrease  sites  a t an " e x p o s e d "  standing  crop  from  sheltered  partly  no s i g n i f i c a n t  L.  the  found  also  difformis  Although  at  of  certainly while an  these  i s  species.  restricted  biotic  algal  i t  by  interactions canopy)  are  95 also such  important. fine  some o f  of  this  study  d i s c r i m i n a t i o n s , but  more  general  these  The  species  Pelvetiopsis Nudibranch. associated exposed  Zone  II  at  permitting higher shown  case,  higher  zones  the  R i c k e t t s et a l . ,  the  "algal  turf"  in  in  (1981)  has  than  turfs  of and  were  and  may  have  action,  sand  II  long  at  resistant  at  major  and  to  at  the  former  N_j_  with  been  larix  longer  was  much  secondary  changes  reported  short  in  by  influences  the  Dethier of  wave  herbivory.  species"  Vancouveriensis II  In  between  r o p e - l i k e , with  axes.  the  Vancouveriens i s  understory  and  to  herbivores.  differed  Similar  have  due  to  larix  Nudibranch,  texture.  been  Hay  Nudibranch.  wiry,  species  abrasion,  Corallina  more  Zone  of  p h y s i o l o g i c a l damage due  Neorhodomela  but  softer  (1982),  are  number  elsewhere.  less  tough,  bushier a  found  suffer  branchlets  Zone  of  wave  species  this  in  1949;  more  large  of  turf"  presence  at  characteristically  relatively  Miller,  I  a  thalli  Bamfield,  of  Zone  of  morphology  "obligate  been  in  coexistence  Haines  of  only  phenomenon,  at  branchlets  and The  s t r e s s and  and  about  self-reinforeing  III  shorter  statements  for  a  morphology  secondary  allow  be  The  the  not  may  abundances that  found  the  1971).  the  was has  Nudibranch  desiccation  Zone  1imitata  (Rigg  does  possible.  alga  shores  Dayton,  are  This with  1968;  scale  by was  Nudibranch,  was Dayton found in  Zone  classified (1975). as  part  III  at  as  However, of  the  Haines,  an at  "algal and  96 under thus  the seems  s e s s i l e canopy erroneous  "obligate"  to  vancouveriensis Haines, the  the  onset  This heat  also  signs  with  as  overall  were  even  secondary  the beginning rainfall mm),  unusually  t h e summer  t h e summer. both  sites.  t o d e s i c c a t i o n or  the standing  lower  1982.  in  This  the  t h e two y e a r s . factors  slightly  crops summer  suggests  t h e two p e r i o d s was  at  plant.  environmental  during  At  some  However, monitored  (see Chapter  lower  and a i r  i n 1983. period,  many  of  however, 1983.  of these  o f t h e new for Bamfield  a n d i t seemed warm  to this  very  with  population  at  exposure  were  spring.  survived  observed  an  Corallina  disappeared  the  a n d H_j_ s e s s i l e ,  temperature  spring for  May;  It  as  t o be  stress.  virtually  still  species"  similar  water  crucial  recruitment  (660.3  with  appear  i n the early  d i f f e r e n c e between  higher  winter-early  record  harmful  F\ d i s t i c h u s  heat  in  limited  f o r the various  temperature  and  weather  were  relatively  The  abundant  of bleaching  climatic  although  or  but  compared  values  but i t does  declined,  that  III at Nudibranch. vancouveriensis  III population  s t r e s s c a n be v e r y  1983  2),  most  warmer  t h e "common  the  was  suggests  As of  species,  desiccation  Zone  of  Nudibranch Definite  to describe  understory  susceptible  i n Zone  and  may  This  i s  species  year's was  have  growth.  as i f the winter  rough.  In  the  ( e . g.  recorded  addition,  been  the late time  H_;_ s e s s i l e An  1982-83 there  )  all-time  i n February of  of  was  1983 was some  97 concern  that  Barkley were  the E l Nino  Sound.  "behaving  Loligo  I t was oddly".-  opalescens  literally  Chrysaora  melanaster  i t s environs.  year-to-year effects been  in  such  a contributing factor.  growth It  significant  be n o t e d  that  the  1982 a n d summer  stressed  that  been  found  f o r many  intertidal  such  variation  "baseline"  studies.  in  abundances this  and  departures  as  discussed  by  this  Inlet  observed to  the  may  have  of e l e v a t e d  water  the  a  from  influence.  no  recruitment  statistically  macroalgal Jones  the  a l .  crops (1979)  i n abundance They  value  noted  standing  et  organisms.  (1958)  to irregular  Falk  were  1983.  limited  in  of environmental  possible  but  yearly variations  Conover  attributed  number  the crops  disrupted  there  also  unusual  various  in Bamfield  periods  adversely  differences- in  summer  algal  Sound,  was  scyphomedusan  standing  Short  have  that  i n March,  the  found  squid  of s p o r e l i n g s .  should  between  run of the  attribute  algal  into  species  addition,  as  to  animal  occurs  In  were  i n Barkley  have  spawning  1983.  in  had extended  various  annually  hesitate  o f an E l N i n o  may  that  Brandt,  variation  temperatures and  which  species,  I  1982-83  The u s u a l  nonexistent oceanic  of  obvious  Berry,  typically  and  event  of  have  concluded short-term  yearly differences  Massachusetts  estuary,  factors  weather, e t c . )  (severe  the normal  factors. (1974),  Continuous  seasonal  and  values  of  Experimenter-induced must  also  sampling  bias,  be c o n s i d e r e d over  a  a  as a  fifteen  98 month  period  through  may  have  the i n t e r t i d a l  animals,  etc.  site,  visited  only  the  affected  can  However,  intervals,  minimum  number  variance  estimates,  should  induced  effects.  crops  emphasize  exceeding duration, of  one  year,  dislodge  have  for  any  variations  in algal  three  the  of  experimenter  studies, years  each  reasonable  minimized  and probably  macroalgae.  collection  to obtain  long-term  crush  transects at  t o p r o p e r l y and a c c u r a t e l y a s s e s s  intertidal  tramping  plants,  and the  of quadrats  observed  the need  transects;  the use of three  a t six-week  The  easily  the  standing certainly  or longer i n productivity  99 CHAPTER  Herbivores macroalgae small  FOUR -  may  in  a  INVERTEBRATE  affect number  s p o r e l i n g s , as well  the  productivity  o f ways. as  ABUNDANCES  By f e e d i n g  preying  upon  herbivores  could  severely  reduce  equivalent  rates  of  photosynthesis,  standing also  crop  the  lower  influence vegetative  on  growing  tips.  be  as simple  as  this,  may  productivity  at high  differentially expect  abundances may  (Hay,  1981;  restrict  invertebrates (Gunnill, A  Lodge,  1976;  may  be  1982; H a w k i n s  on  of  Lubchenco  by  At  lower  the  They  thus  species, feedback  may n o t back  maintain  example,  associated  have>  and  1961;  an  also algal "algal  distributions 1981),  other  with  macroalgae  the  impact  1983).  examined  macroalgae  between  while  abundances  and H a r t n o l l ,  may  a n d one might loops  may  feeding  addition,' herbivores  closely  Castenholz,  crops.  cropping  and  Jernakoff,  workers  the  and  plants,  of herbivory  and  intertidal  1950;  For  herbivore  Underwood  number  herbivores  negative  and h e r b i v o r e s .  turf"  In  mature  selective  self-shading  influence various and  by  herbivores,  levels.  on s p o r e s  standing  the effects  for  intertidal  productivity.  propagation  prevent  positive  algal  the algal  However,  macroalgae,  and  net  of  (Lodge, Dayton,  1980, 1983; U n d e r w o o d ,  of  1948; B u r r o w s 1971;  Menge,  1980; Underwood a n d  100  Jernakoff,  1981;  Petraitis, have  Bertness  1983;  been  et  a l . ,  Underwood  et  studies  which  relationships  between  herbivory  (1974)  Oregon algal  studied  coast  and  abundances,  algal  proper  may  The  of  Dahl,  Lubchenco Gaines,  1981;  Cubit  (1974)  were  most  and  possibly  intertidal of  algae This  those  between important  the  species  chapter  intertidal  previous community  general  that  herbivory  these  structure  be and  1980;  Lubchenco  Jernakoff,  and  1983).  interactions,  and  productivity,  algal  of  the  interactions. data  which  important  on  the  have  Although  no  feeding  were  reference  to  previous  also or  the  on  high  abundance  found  may  of by  intertidal  affect  caging  work  in  abundances  been  influences  may  abundance,  organisms  species  productivity. performed,  1978,  influenced  thus  of  (Castenholz,  factors  the  type  biological  composition,  presents  to  1983;  the  structure.  this  factors controlling  invertebrates  workers  community  1979b;  limit  "swamp"  Lubchenco,  Sousa,  the  conditions  to  that  on  could  occurrence  Hartnoll,  Physical  affecting  as  suggest  1978; and  herbivory  on  1975;  concluded  areas.  by  more  community  great  the  productivity.  environmental  influence  Dayton,  Hawkins  those  the  of  Menge,  especially  so  studies  be  1964; and  be  their  other  may  the  while  there  examined  algal  intertidal  under  limiting  phenomenon  high  1983;  However,  directly and  that  productivity  results  have  concluded  herbivores,  1961;  the  Jernakoff,  a l . , 1983).  no  Cubit  1983;  algal  experiments allow  an  101  estimation  of  productivity Fucus  the  i n the study  distichus,  examined  possible  experiment.  Methods  and M a t e r i a l s  conjunction  intertidal  macroalgal  invertebrates estimate  mussels)  of  this  of  and mussels competition  disseminules Nassichuk,  impractical  were  method for  algal  may  have  for  not of  was  column,  crop given  limpets).  filtering etc.  1976; H a w k i n s ,  purpose  of the p o s s i b l e  standing  and  to  barnacles,  main  influenced algal  space,  the water  idea  attention  (littorines  1975; Menge,  interactions The  from  on  some  The  3), the  sampled  amphipods,  are  estimate  (see Chapter  and counted.  to obtain  between  di st ichus  to  quadrats  (except  particular  gastropods  program  the  algal  and l i t t o r i n e s  and a Fucus  crops  of  crops  herbivory  herbivorous barnacles  i n each  was  thus  species,  standing  on  relationships  analyses  collected  sampling  of h e r b i v o r y  the sampling  standing  were  productivity,  through  present  algal  and  effects  with  The  algal  regression  clearing  In  area.  secondary  using  impact  of  to the Although  productivity reproductive  (Dayton,  1981),  and  these  1971; species  examined. collecting  estimating  amphipod  invertebrates  proved  d e n s i t i e s and  probably  102  slightly  underestimated  limpets.  Substratum  etc.)  to  Dayton,  should  littorine reduced  "natural  seasonal  therefore growth  an  than  the  at the study  d i st ichus  t h e summer  spring  levels.  in  F^ di st ichus  experiment  canopy  influence  of secondary  intertidal.  In  addition,  over  time  1 m  plots  after  crops  both were  appeared  the possible  and  secondary  this  to  natural was  test  stress  on l i t t o r i n e  macroalgae  that  littorines  designed  alleviated desiccation  important  presence/abundance  was  relative  This  resumed, and  field  sites.  standing  littorines  growth  quadrat  the true  of  i t  presented  i t was o b s e r v e d  F\_ d i s t i c h u s ,  when  This  distichus  with  i n each  c l e a r i n g " , and so t o e v a l u a t e  decline  modified.  lower  1982-83  made  densities  estimations  and Fucus  between  species  as  and  crevices,  of the gastropods  densities  winter  densities  interactions  II)  realistic  the  littorines  (barnacles,  invertebrate  viewed  i n comparison  be a  the  as  The be  of  a l l the i n d i v i d u a l s  of the species  During  algal  1971).  but  magnitude  F.  heterogeneity  collect  therefore  values,  to  densities  and the c r y p t i c c o l o r a t i o n  impossible (see  the  i fthe  and  was  abundances and  i n t h e upper  (Zones  changes  in  the c l e a r i n g  I and  species  event  were  studied. Experimental Wizard side levels  i n February of  the  2  1983.  set  approximately  of  Two  were plots  transects  i n the middle  established were  a t Haines and  cleared  at the sites, o f Zones  at  on  each  vertical  I and I I ;  there  103 were F.  thus  eight  d i st ichus  illustrated (0.0625  F.  removed  I n t h e two c e n t r a l  Figure  quadrats,  in  one  These  25 cm x 25 cm  in  di st ichus  were  and  experimental six  half other side  and each  as  The  described  sampling  algal  in  were  late-July.  experimental i n Chapter  program.  also were  Removal). by  a  "experimental were  made  on  crop and  normal  o f F\_ d i s t i c h u s  sampling  were  i n mid-June  One o f t h e 1 m sites  quadrats  secondary  were  in  qualitatively  determinations  plots  study  and  abundances,  followed  Quantitative  a t both  were  controls.  experimental  zone  understory  standing  the  was  plants  the  and i n v e r t e b r a t e d e n s i t i e s 2  the  measurements  during  as  x 25 cm  uninfluenced  considered  on  25 cm  i n height)  totally  A l l  plot  (Canopy-Only  invertebrate  quadrats  of the 1 m  time.  and  crop  as  development  months.  half  collected  each  understory  quadrat  were  Data  5 cm  site.  F^ distichus  quadrats  the  quadrats,  considered  species,  standing  other  only.  densities  Growth  next  while  from  canopy  these  and a l l q u a n t i t a t i v e  littorine  algal  the  canopy,  quadrats  program  of  Removal),  intact  these  a l l the  (plants approximately  (Total  quadrats"  9.  removed  each  in  left  F.  at  were  2  d i st ichus  plots  and l i t t o r i n e s  m )  removed;  experimental  was  2  the  algal  made  on o n e -  and  on  sampled  3 f o r the macroalgal  for  of  plots  sampled  the  and  the  from  each  at  each  analyzed  standing  crop  Figure  Diagram  of  p l o t s set up  9  the 1 m i n the  clearing  experimental  Fucus  distichus  experiment.  Hashed Area = c l e a r e d of a l l algae and i n v e r t e b r a t e s E x p e r i m e n t a l Quadrats (25 x 25 T o t a l C l e a r = a l l algae and removed  cm): invertebrates  Canopy Only = canopy |\_ d i s t i c h u s only and i n v e r t e b r a t e s removed; u n d e r s t o r y ]?\_ d i s t i c h u s l e f t intact  105  106 Results  Except  for  Littorina  scutulata  Gould  and  sitkana  Philippi  (herbvivorous gastropods),  invertebrate  abundances  at  study  low.  Limpets  were  in size  (less  each  only in  rarely  Deshayes  was  II  I I I . no  usually  mm  Dana  (hermit crab)  was  less  than  Adams, Gmelin  16 n r .  The  2  Thais  emarginata  found  sporadically  were  Amphipods  Haines  only  (overall  ochraceus  were  sites,  Nudibranch  (overall  Katharina  tunicata  of  11a-d).  Wood  were  sites Both  have  widespread densities  Dall  was  rarely abundant  density was  =  found  density  abundant  a n d i n Zone  in  2  i n Zone  ) .  found  The  at  i n Zones  only  i n Zones  Zones  I  2  s p e c i e s of L i t t o r i n a  were  ) .  three  'The  chiton  II and I I I  ) .  and  I at Nudibranch  III  II and I I I a t  n r  2  was  seastar  the  3.2  = 6.4 n r  limited  (gastropod)  larix  = 24 n r  density  mean  somewhat  Neorhodomela  was  mean  (overall  Littorines sheltered  mean  but  to  columbiana  with  Brandt  sheltered  Nudibranch  observed  Amphissa  associated  Pisaster  and  10  accurate e s t i m a t i o n of t h e i r  s p e c i e s were  distributions.  at  lamellosa  and but  averaged  than  found  possible. Three  at  hirsutiusculus  funebrali s  and T h a i s  occurrence,  small  but d e n s i t i e s  Tegula  Zones  relatively  usually  Pagurus  common,  gastropods  were  and were  length).  fairly  in  site  II  of  (Figures found  at  the I0a-d each  107 site,  but  L_j_ s i t k a n a  was  Wizard.  Results  of  littorine  density  over  only)  are  two-way  very  multi-way site,  presented  The  one-way only  significant  were,  analysis  (p<0.0l)  found  well-defined  Zone*Month  i n t e r a c t i o n was  The  d e n s i t i e s of  greatest were for  not  18).  during clearly  the  Littorina but  with  differences (Table  18.  rare  at  variance  The  I  of  and  II  significant  analyzed  using  the  the  scutulata  was  the  However,  mean  L_j_  changes  L_;_ s i t k a n a  at  L_;_ s i t k a n a ,  each the  scutulata general, summer  only  but  S-N-K  the  Zones  density. in  Zone  I. the  non-significant were  found  densities  these  and  Nudibranch*Month  most  abundant  Zone  at  were  differences (p<0.0l)  analysis  in  the  site.  scutulata  by  sitkana  reflected  abundance  months,  of  greatest  interaction  sitkana  into  Although  neither  was  S-N-K  months  1982.  in  sitkana  but  significant,  distinguished  Zone*Month  in L^  17),  divide  abundance  in In  changes  summer  Site*Zone  contrast  seasonal Haines  in  sitkana  significant  In  and  and  (Zones  (Table  groups.  greatest  site,  different  of  zone  further  not  i n d i v i d u a l seasonal  each  17  Haines  did  were  At  and  seasonal  at  densities  showed  Haines  ANOVAs.  abundance  particularly  were  at  analyses  month  in Tables  i n t e r a c t i o n terms  respective  abundant  interactions. I  at  each  site  Helby. Results  littorine  of  the  d e n s i t i e s on  multiple various  regression abiotic  analyses  environmental  of  factors  Figure  10 2  Mean d e n s i t i e s standard  (number per 0.0625 m  deviation)  i n Zones I and I I  of  Littorina  a t each study  each "sample month".  A) Haines B) Helby C) Wizard • D) Nudibranch  •  = Zone I  • = Zone I I  ± one sitkana  site  for  a) H a i n e s  Month  o  Month  Month  Figure  11 2  Mean d e n s i t i e s standard  (number per 0.0625 m  d e v i a t i o n ) of L i t t o r i n a  i n Zones I and I I  a t each study  each "sample month".  A) Haines B) Helby C) Wizard D) Nudibranch  •  = Zone 1  •  = Zone I I  ± one  scutulata site  for  L . s c u t u l a t a (No. -0.0625m~ ) 2  M  O J -  O i  « 1  w  O •  •  Month  L . s c u t u l a t a ( N o . • 0 . 0 6 25 m " ) 2  ill  Table  17.  Analysis  of v a r i a n c e  (# 0 . 0 6 2 5 m - 2 )  SOURCE  Haines*Zone Helby*Zone Wizard*Zone Nud i b r * Z o n e  a n d II  at  the study  MEAN SQUARE  F-RATIO  22899 1822 1 9085.8 4813.9 16273 4269.4 12551 1 .5617E+05 2.4429E+05  3 1 3 9 25 9 24 840 914  7633 .0 1822 1 3028.6 534.87 650.92 474 . 38 522.98 185.92  41.055 98.007 16.290 2.8769 3.5011 2 . 5515 2.8129  sites  PROBABILITY  0.00000 O.OOOOO 0.00000 O..00237 0 ..00000 O..00678 0 ..00001  ANOVAs  I*Month II*Month  Ha i n e s * M o n t h Helby*Month Wizard*Month Nudib'r*Month  I  densities  DF  SOURCE  Zone Zone  i n Zones  L i t t o r i na s i t k a n a  SUM OF SQUARES  Si t e Zone S i te*Zone Month S i te*Month Zone*Month S*Z*M Res i dua1 Total  Interaction  of  DF  MEAN  SQUARE  9,424 9,471  916.00 58 .867  266 194 251 166  1946.9 119.52 28.187 403.70  1 , 274 1 ,202 1 , 259 1 , 172  1936.2 878.99 276.80 7350.0  F-RATIO  2.1030 0.85S91  PROBABILITY  0.02816 0.56398  ns ns  1050 1803 6563 3307  0.00006 0.30950 0.10008 0.23876  ** ns ns ns  42.673 8.9488 16.873 27.580  0.00000 0.00312 0.00005 0.00000  ** * ** **  00  Table  18.  Analysis O  SOURCE  0.0625m-2)  i n Zones  DF  14772 17488 4790.4 10946 12491 3922 . 2 9826.9 1.1411E+05 1.8583E+05  3 1 3 9 25 9 25 838 913  L i t t o r i na s c u t u 1 a t a I  and  II  of  the  MEAN SQUARE  4924 .0 17488 1596.8 1216.2 499 .62 435.80 393.08 136. 17  densities  study  sites.  F-RATIO  PROBABILITY  0.00000 * * 0.00000 00000 00000 00000 * * 00081 00000  36. 160 128.42 11.726 8.9312 3.6691 3.2004 2.8866  ANOVAs  SOURCE  Zone Zone  v a r i a n c e of  SUM OF SQUARES  S i te Zone S i te*Zone Month Site*Month Zone*Month S*Z*M Res i dua1 Total  I n t e r a c t ion  of  I*Month II*Month  DF  MEAN SQUARE  9.423 9,471  1 100.00 466.60  Haines*Month Helby*Month Wizard*Month Nudi b r * M o n t h  9,265 9, 194 9,254 7 , 166  231 . 12 924 . 18 127.64 191.16  Ha i n e s * Z o n e Helby*Zone Wi z a r d * Z o n e Nudibr*Zone  1 , 273 1 , 202 1 , 259 1 , 172  3616.2 794.88 1603.0 2012.6  F-RATIO  PROBABILITY  5.0669 3.4474  0.00000 0.00039  ** **  5249 6518 0796 2421  0 . 13901 0.00031 0.00000 0.00299  ns ** ** *  25.557 2.8359 89.005 37.984  0.00000 0.09372 0.00000 0.00000  ** ns ** **  120 (see  Chapter  in  Table  F.  distichus  3)  19.  and  Both  only  L.  Per  sitkana.  cent  time  (biomass  littorine  densities)  ( Cladophora only  rarely  standing  crop  maximum  they  was F.  in  plants no  d i s t ichus  those were  1,14df;  crop  Recovery in  Zone  was  some  and  22,  at  greater  I I , and  at  20.  i n the  Secondary etc.)  were  quadrats.  of  The  not  these  of  littorine  crop  was  quadrats  was  was  Wizard  macroalgae,  probably  back  the  plants  ANOVAs  of  densities  greatest where  i n F\  greatest  are  in  There  were  biomass  at  distichus  Zone  II  (F=12.733  than  20).  understory  F.  much  Canopy-Only  Wizard  but  biomass  (Table  the  di st ichus  distichus less  at  Removal).  P=0.62889ns),  Fucus  clearing  respectively.  differences  quadrats  other  Results  (Canopy-Only  Wizard  for  highest  F\_ d i s t i c h u s  were  dying  and  was  analyses.  experimental  summer.  1,14df;  P=0.00309).  experimental  for  standing  zonal  I  species  crop  intact  (F=0.24415  standing  Zone  with  crop  the  , Gigartina papillata,  experimental  left  the  has  in Table  the  21  air  i n both  presented  these  standing  significant  Haines  for  to  from  shown  regression equation  are  i n the  in Tables  Fucus  exposed  are  standing  and  spp.  during  distichus  multiple  crop  regressions  E\_ d i s t i c h u s  achieved,  observed  presented  and  data  distichus  data  of  standing  significant  coefficients  experiment  found  F^  the  quantitative  species  show  but  in  correlation  The  di st ichus  species  biomass,  significant  partial  Fucus  the  i n the control  Removal  cleared means.  treatments,  Table  Multiple  19  regression  L i t t o r i na  of  densities  scutu1ata  environmental  MULTIPLE  analyses  L i t t o r i na on  selected  f a c t o r s and Fucus d i s t i chus  = -4.7  MULTIPLE Partial  -  Partial  r r r  SE  + 0.3(AIR  -  1.2(SAL)  P=0.0112 P=0.0000 P=0.0000  -  1.1(WAVE  SE  EXP)  + 0.2(AIR  = 7.8590  Correlation Coefficients: r r r  = -0.03258 = -0.27383 = 0.48808  P=0.0047 P=0.0182 P=0.0000  REGRESSIONS ON FUCUS DISTICHUS STANDING CROP ONLY LSITKANA  = 0.6  Note: Fucus  + O.OI(FUCUS)  = 0.38253  LSCUTULATA  EXP)  = 8.4281  = -0.29322 = 0.46694 = 0.61559  R = 0.57521  SALINITY WAVE-EXP AIR-EXP  r  standing  Correlation Coefficients:  = 33.4  MULTIPLE  + O.OI(FUCUS)  R = 0.68698  H20-T FUCUS AIR-EXP  LSCUTULATA  1.1(H20-T)  = 5.0  = 0.32588  1,74 +  df  p<0.0006**  SE =  10.57  SE =  8.96  O.OKFUCUS) 1,74  df  p<0.0041**  L i t t o r i n e v a l u e s i n numbers p e r 0 . 0 6 2 5 m ' s t a n d i n g c r o p i n g d r y wt m~ 2  and  abiotic  REGRESSIONS  LSITKANA  r  s i tkana  EXP)  crop.  T a b l e  2 0 .  F u c u s  d i s t ( g  i c h u s  d r y  D A T E  * t  m - 2 1  T O T A L  a n d  W I z a r d / 1 3  O t h e r  4 5 7  . 8  2 . 7  L e f t  6 7  1  6 . 0  R i  2 1 6  J u n e  g n t  %  C o n t r o l  H a l n e s / 1 0  J u n e  9 8 6  L e t t  5  5 5 9  J u l y  t  H a i n e s / 2 2 L e f t  7  i g h t C o n t r o l  R E M O V A L  O t h e r  L i t t o r ; n e s  8 0 0  6  4  3 8  2  4  0  0  8  0  0 0  .2  0  0 7  0  3  27  6  5 5 2 1 146  2  6 1 u  0  1  8  J  0  5 3  7  0  7  2  0  9  2 5 38  0  1 1 6  0  16  0  1  2 0  11.5  . 7  72  10  0  1 8 . 1  6 1  8  3 5  2 3 2  1  7 8 2  6 5 . 4  0  14  5 4 2  9  L e f t  1 2 9 .  5  R i g h t  148  4  2 5  .6  J u n e  C o n t r o l  i n e s /  1 0  J u n e  7 7 8 .  37  0 3  4  5  0  18. e  0  .  0  . 9 7  2  7  3 4 0  2  7 5  8  17  2  12  16  9  J u l y  L e f t R i g n t  24 1 2 0  7  H e i n e s / 2 2  J u l y  •  2 7  9 6 1 6 . 5  • • • • +  3  2  0 8 . 6 7  0  0  1  0  1  6  0  9  4 3 5  4  2  3 7  3 7 . 5 -  8  •  193  '.  8  2 31  3  9 7  3 9 2  0  0  3 0  3 2 0  0  15  6 3 7  9  10  8  5 5  6  125 146  9 4  2 6  18  8  192  37 2  5 6 7 2  0*  J  7 0 4  0 7 * «  1 1 1  8  5 . 6 - •  18  7  1  9  0  2  0 9 * «  51  .  f e n e s t r a t a  s p p s p o  C i a d o p n o r a d i f f o r m i s L  2  8  C ra d o p h p r a  4  0 *  0  4 0 14  0  8  1  1  C 1a d o p n o r a  1  1  2  C o n t r o l  ••  8 .6  2  7 2 4  481  17  6 4 0 2 0 4  L e f t R I g h t  2 2  9 6  8  33  10  1 3 . 6  36  C o n t r o l  6  2  5 7 . 7 - • •  0 4  17  7  6.0 35  1 , 3  C o n t r o l  W i z a r d / 2 6  3 5  3  6 14  L e f t R i g h t  N o t e  0 . 0 6 2 5 m - 2 l  1J.  W i z a r O / 1 3  7  f u c u s  3 2 5 6 7  7  0  2  0  R "I-  'A  ( »  c r o p s  . 0  2 7  0  3 . 9 J u l y  2 6  5  2 9  C o n t r o l  ZONE  18  1  0  R i grit  H  t o n n e s  6 "  0  W i z a r d / 2 6  X  d e n s i t i e s  s t a n d i n g  C A N O P y - O N L ' L11  .0  1 2 9  2 . 1  C o n t r o l  L e f  1  9 . 7  R i g h t  X  l i t t o r i n e  m a c r o a l g a l  I  Z O N E  V.  e x p e r i m e n t ,  R E M O V A L  f u c u s  H a  c l e a r i n g  d if f Qrrn is  .  .  c o r n u c o p i a e  r I  1  p a p i ) l a t a  .  s p p  p a p > C O r n u c o p  M a t a 1a e  .  ,  C O r n u c o p i a e P o i y s i p n p n » a S P D  C I a d o p n o r a  s p p  S_  U_  l o m e n t a r  i a  Table  21  Fucus d i s t ichus of  Fucus  clearing  d i s t ichus  experiment:  standing  experimental  SOURCE  Si te Zone S i te*Zone T i me S i t e * T i me Z o n e * T i me S*Z*T Remova1 S i te*Removal Zone*Remova1 S*Z*R T i me*Remova1 S*T*R Z*T*R S*T*Z*R Res i dua1 Total  SUM OF SQUARES  .1 .2571E+05 97583 69294 58.590 1 1389 2375.3 7966.4 1.1375E+05 6157.7 1 1389 4600.8 2027.3 19459 104.04 215.80 71909 5.4399E+05  DF  16 31  crop  A n a l y s i s of (g  dry  variance  wt m-2)  in  the  quadrats.  MEAN SQUARE  1.2571E+05 97583 69294 58.590 1 1389 2375 . 3 7966.4 1.1375E+05 6157.7 1 1389 4600.8 2027.3 19459 104.04 215.80 4494.3  F-RATIO  PROBABILITY  27.972 21.713 15.418 .013037 2 . 5341 0 . 52852. 1.7726 25.31 1 1.3701 2.5341 1.0237 0.45107 4.3297 .023149 .048017  0 . 00007 * * O. 0 0 0 2 6 * * O. 0 0 1 2 0 * * 0. 91052ns 0 . 13097ns 0.47773ns 0.20172ns 0.00012** O.25893ns 0.13097ns O.32670ns 0.51141ns 0.05388ns 0.88097ns 0.82932ns  Table  22.  Fucus  distichus  littorine  SOURCE  Si t e Zone S i te*Zone T ime S i t e * T i me Z o n e * T i me S*Z*T Removal S i te*Remova1 Zone*Remova 1 S*Z*R T i me*Remova1 S*T*R Z*T*R S*T*Z*R Residual Total  clearing  densities  (#  SUM OF SOUARES  1225 . 1 98.OOO 28.125 0.0 78.125 242.00 465.12 406 . 13 18.000 9 1 . 125 24.500 15.125 98.000 1.1250 60.500 2225.0 5076.0  1  1 1 1 1 1 1 1 1 1 1 1 1 1 1 16 31  experiment:  0.0625m-2)  in  Analysis  of  the experimental  MEAN SOUARE  F -RATIO  1225 . 1 98.000 28.125 0.0 78.125 242.00 465.12 406.13 18.000 91 . 125 24.500 15.125 98.000 1.1250 60.500 139.06  8 8099 0 70472 0 20225 0 0 0 56180 1 7402 3 3447 2 9204 0 12944 0 65528 0 17618 0 10876 0 70472 .0080899 0 43506  variance  of  quadrats.  PROBABILITY  0 0 0 1 0 0 0 0 0 0 0 0 0 0 0  00906** 41357ns 65895ns OOOOOns 46442ns 20568ns 08612ns 10679ns 72372ns 43011ns 68026ns 74583ns 42357ns 92945ns 51890ns  125 The was  only  significant  between-sites;  those  at  means,  littorine  the  Zone  littorine and  in  Total  22  (Table  July  Zone  with  20).  I,  13  Removal  quadrat.  quadrats  the  Canopy-Only  control densities.  Removal  were  Removal  quadrats  occasionally  greater,  than  Zone  were  control  At  Wizard,  treatments  quadrat,  when  densities in  while  not  than  i n a l l but  II  Removal  reduced,  the  Haines  Littorine  much  Canopy-Only  with  at  in  abundance  greater  reduced  greater  June  were  Compared  Canopy-Only were  littorine  Wizard  d e n s i t i e s were  abundances  the  compared  d e n s i t i e s at  Haines  I,  difference in  as  the  c o n t r o l means  other  intertidal  those low,  in  and  (Table  the the were  20).  Di s c u s s i o n  Compared  with  invertebrate much  lower.  spp.) 400 were low  Dayton  densities  nr  2  on  rare numbers  Lubchenco, been  densities  the  Australia,  680  Washington study  New  1980),  reported  (1971)  of  i n the in  in  but  Bamfield  maximum  irr  Thais  and  2  coast;  sites.  high  area  reported  England  (Menge  limpet  the  both Limpets  densities  (  limpet  spp.  were  d e n s i t i e s of 1978).  were  In  Cellana  Thais New  (  and  also  and  generally Acmaea  d e n s i t i e s of  limpets  (Lubchenco  1976,  communities,  thaids  present  in  Menge,  1978;  lapillus  have  South  tramoserica  Wales, )  were  126 between  65  and  Underwood large  et  and  a l . ,  in England,  structuring  Limpets  1948;  much  limited area.  on  Stephenson were  but  those  and  abundant be  (Lodge,  and  important  1948;  to  keep  only  when  in  this  Burrows  thaids  Stephenson  intertidal present study  1971;  1981).  intertidal  relatively  to  Dayton,  Jernakoff,  and  both  found  1950;  the  were  1981;  1964).  Lodge,  limpets  Jernakoff,  shown  reported  than  and  shores  algae,  and  impact  limpets  of  and  been  English  been  higher  numbers,  Limpets  Southward,  Underwood  small  (Underwood  have  on  clear  Borrows  1980;  and  have  substrates  2  1983).  agents  L o d g e , . 1950;  densities  irr  86  Considering had  community  in  unimportant  (Lodge,  Underwood,  probably  (1961a)  also  on  in  their  only the  study  suggested  Vancouver  a  that Island  shores. Nassichuk grazing  on  However, found  at  (1975)  Fucus the  the  in  small study  sites  d i s t i c h u s standing  in  Zone  Pisaster better  at  uneven  barnacles); combined limited  thus  with F\  on  the  may  have  barnacles.  lack  presence  di st ichus  (16  growth  of  the  (see  low  nr )  of  had  only  The been  hi rsut iusculus shore this  a  lack due  as  levels.  hermit  impact  of  distichus  E\  predation  generally that  barnacles "algal Nassichuk,  crab  small  to  Fucoids  (such of  and 2  levels.  substrata the  Pagurus  pools  probably  crop  Nudibranch  ochraceus on  tide  populations  F.  II  observed  this  turf", 1975).  by  survive  provided  in  on  may  by  zone, have  However,  127 the  low  standing  Nudibranch/Zone important Dayton  (1975) as  ability  Zones  a  II  the L.  near  algae  small  only  showed  (Tables  and  18).  by  Behrens  Bertness  et  a l .  combined  2100-8000  nr  and  low  ,  densities (maximum  have density  The  observed  been =  due  that  to  the  Although performed  no in  probably  assemblages  large  in  in  New  nr  2  highly  sites  Littorina (Petraitis, found  225  were  in  nr ; 2  on  nr  zones,  and  also  were  2  1ittorea 1983).  Dethier,  observed  similar Island  Lubchenco  in  the  L.  on  Lower  pools  in  1982),  and  of  high,  England  to  (1980)  densities  New  tide  and and  and  littorine 1-649  were  variable  Vancouver  England.  , and  numbers  scutulata  densities  for  respectively,  2  were  between  (1971)  of  4000 n r  in  i n t e r a c t i o n terms  4-847  densities were  site.  Katharina  herbivore  Littorina  total  intertidal,  Average shores  2  an  concluded  were  macroalgal  densities  (1983)  reported  of  in  had  that  animals.  this  present  differences  significant  found  the  at  macroalgae the  plants  also  also  grazing  gastropods  seasonally;  those  on  and  (1975),  invertebrates  significant  growth  on  the  action  densities  "swamp"  Dayton  Littorine  17  effect  of  Nudibranch.  herbivorous sitkana.  wave  tunicata  on  at  stature  Bamfield,  to  impact  III  that  similar  little  based  and  The  had  small  E\_ d i s t i c h u s  studying  study, only  on  the  experiments  had  suggested  found  of  and  reported  herbivore  this  I  effect  tunicata this  crop  mid,  shores.  Long  Island  littorine Washington in  a  New  128  Hampshire Witman  estuary  and Mathieson,  (maximum  density  Except abundant L.  2).  vertical  i n Zone  in  pools  and L.  Rigg  inhabit  1975).  heights  o f maximum  I began  of  desiccation F.  littorine Wizard  littorine  densities  than  quadrats.  alleviated  1981).  a t about  abundant (1975) and MLLW,  + 2.1-2.3  in  m  than the  this  related  canopy,  study  (Table  20)  a t Haines  at  show  but  that I at were  II experimental  a F^ d istichus  stress  from t h e  a n d i n Zone  canopy,  the  reduces  results  i n the Wizard/Zone that  to  which  The  F\_ d i s t i c h u s  desiccation  b u t on  Chow  lower  been  stress.  suggested  the  L^ scutulata  found  have  reduced  of a  in  Table 3).  experiment  were  (see Chapter  was m o r e  slightly  distichus  the controls This  may  predation  clearing  m;  most  due t o  1.0 a n d 4.9 m a b o v e  density  o r +2.8  Fucus  i n the absence  greater  have  a  was  been  sitkana,  that  scutulata  densities  and  d ist ichus  of  were  significant  have  and  L^ sitkana  between  Georgia  differentiation  noted  level  a t +2.4  Littorine presence  areas  This  may  1971; McCormack,  (1949)  densities  (Chow,  that  of a  and winter  scutulata  i t appeared  Miller  maximum  (Zone  of  littorines  a t Helby  little  of  1975).  The l a c k  the f a l l  reported  (Behrens,  and  sitkana  with  I during  zonation coasts  site.  Hardwick-  2  Strait  at Helby,  difference  (1971)  exposed tide  I at each  155 m" ;  and i n t h e  scutulata  zonal  Behrens  1983),  =  2  i n Zone  damage  density  = 300 rn" ; N a s s i c h u k ,  for  scutulata  log  (maximum  Haines  canopy  may  and  in  129 Wizard/Zone at  I , b u t was  t h e more  algal  wave-exposed  "whiplash" While  greater  by  i n Zone  gradient  noting  Site*Zone  the  HAIN-I  were  increasing differed. shores L.  wave  sitkana  Behrens ratio  of  increased. ability In  >  showed  however,  be  seen  (p<0.0l) f o r the  >  t h e most  greatest sheltered  found  that to  attributed  U  this  was  most  Zone  II  the p a t t e r n were  greatest  Wizard),  on.  most  the  (Haines)  result  I on  while exposed  shores.  exposure  sitkana  with  i n Zone  (Helby,  a s wave  to withstand  sitkana  in  densities  exposure  L^ scutulata  L.  best  NUD-I,HAIN~II,WIZ-II,NUD-II  abundances  scutulata  o f L_j_ s c u t u l a t a  addition,  >  lower  exposure;  (1971)  She  t h e wave  WIZ-II,NUD-II  a b u n d a n c e s were and  along  can  analysis  > HAIN-11,HEL-11  moderate  (Nudibranch)  the  o f S-N-K  This  consistently  sitkana  L i t t o r ina of  an  scutulata  > WIZ-I  species  to  II  term:  > NUD-I,HEL-I  Both  i n Zone due  I were  i n abundance  not as c l e a r .  > HEL-II,HAIN-I  Littorina  (perhaps  i n Zone  I I , changes  results  L i t t o r ina  site  densities  interaction  WIZ-I,HELBY-I  Wizard  to l i t t o r i n e s  effect).  littorine  than  exposure  detrimental  increased,  densities to  the  the pounding a b u n d a n t on  of  also  greater waves.  sheltered  ,  130 damp  beaches  was  most  shore,  in  the  most  the  species. indicate  Where  and  large  winter.  have  al.  and  (1983).  because^  (Castenholz, Mean  littorine  somewhat similar this  These  lower  lower  than  observations  supports  condition  the  during  are  during  the  also  of  and  this  study  between  these  numbers  in  hospitable does  two  Zone  II  to  these  not  occur  in  there  densities  and  may  the  to  active  1975;  Bertness  the  Bertness result  in et  spring/summer  1982.  standing that  In  of  the  et the  action winter  a l . , 1983). 1983  conjunction  crop  (see  some  general  winter/early-spring  fall  (1975),  i n c r e a s e d wave  less  a  abundances  Nassichuk  (1982) be  was  i n the  littorine  (1961),  due  summer  hypothesis  I  observed,  Dethier  algal  were  small.  declines  are  i n the  observations.  probably  were  Nassichuk,  of  Zone  is less  littorines  densities  broken  scutulata  low  densities  gastropods 1961;  and  Castenholz  (1980),  the  in  in l i t t o r i n e  Cubit  of  the  changes  by  in  competition  winter  very  (Nudibranch).  level  decrease  sitkana  and  (1971)  competition  populations  reported  dislodgement or  thus  Similar  been  Lubchenco  shore  seasonal  relatively  site  coexistence  snail  sheltered  relationships  this  study,  L_;_ s i t k a n a p o p u l a t i o n s  of  and  the  large  possibility  that  a  this  Behrens'  observed  gastropods, because  with  abundances  Their  In  Haines,  exposed  inverse  sitkana  suggest  at  relatively  at  crevices.  agreement  The L.  many  abundant  However, found  with  Chapter  1983  were with 3),  climatic was  131 deleterious In on  to the i n t e r t i d a l  evaluating  macroalgae,  1)  in  this  studies eat  , Cladophora Foster,  L.  scutulata  as  Pelvet ia  conditions  with  have  the  grazing  sources:  grazing,  has ,  been  same  performed,  and performed  studies  littorines  are able  present  that  types  ,  both  because of  of algae,  mainly  species  1982).  In  diatoms,  algae,  such  laboratory  these  ( F\_ d i s t i c h u s  Dahl,  addition,  under Thus,  and  1961;  to eat fleshier Fucus,  some  L^ sitkana  1971).  and  or  information.  , e t c . (Castenholz,  1964; D e t h i e r ,  and ephemeral  in part  the a v a i l a b l e  observed  Laminar i a  (caging  t h e F\ d i s t i c h u s c a n o p y ,  Behrens,  the dominant  environmental  manipulations  found  , Porphyra  Ecological  when  were  1964;  (Dahl,  affect  secondary  only  two  c l e a r i n g experiment  experimental  c a n be made  scutulata  that  from  of l i t t o r i n e  of l i t t o r i n e  i n t e r a c t i o n s with  Previous  may  studies  experiments)  conclusions  1964;  obtained  T h e F_j_ d i s t i c h u s  possible  Ulva  were  no d i r e c t '  exclosure  L.  data  effects  study.  Although  the  the possible  Previous  2)  community.  species  ) as well  as  algae. i n the P a c i f i c  in  conditions.  to reduce high  Northwest  algal  have  standing  d e n s i t i e s and under  Castenholz  shown  crops,  but  favorable  (1961) c o n c l u d e d  that  132 littorine the  densities  appearance  during  the  littorine Dahl  high  on  in  (465 New  nr ) 2  fucoids  herbivores,  and  Littorina  Enteromorpha  and  concluded  low  areas  clear  required Similar and not  to  of  directly  by  heavy not  extracts  was  increasing,  did  and  densities  L^  study  they  the  Although effects  d i d observe  grazing pressure abundant have  shown  at  by  the  that  that on  a  the  had  little  results  for  the  values)  a  sheltered  beach,  by  that  to  these  gastropods. fed  Petraitis could  higher  herbivory  sheltered  of  and  (1983)  keep  bare  by  rocky  alga.  Menge  (1978)  (1983) L^  were beach  analysis  contain  were  the  a l .  algae  Chemical  upon  densities  populations  et  the  littorine  readily  Lubchenco  but  1971).  concluded  1ittorea  plants  prevent  field  a l l erect  site).  to  (twice  Bertness  of  cover.  (1974).  obtusata  but  high  Cubit  algae.  Enteromorpha,  made  but  attractive  L^  of  however,  able  (Behrens,  affected  ephemeral  (1980).  on  areas  by  (1978)  least  littorea  were  2  preventing  diatom  Similar found  not  eliminate established  Lubchenco  Fucus,  scutulata  macroalgae  little  winter, the  rrr  of  intertidal  on  930  were  observations  on  was  that  effect  Lubchenco  thus  and  were  of  capable  high  populations.  of  England,  in  fall  from  densities  perennial  However,  the  Oregon  growth  were  2  cover  that  populations  the  irr  little  densities  prevented  In  had  stated  intertidal  normal  In  established  Littorine  300  diatom  densities  algal  effect  a  summer.  (1964)  sparse  of  of  did  1ittorea removed (  Fucus  of. F u c u s  polyphenols,  133 which  serve  McConnell, a  as a herbivore 1981).  limited  abundances should heavy  impact  noted  littorine growth  Based densities to  the  would  when  the  littorine limited algal  algal  Chapter  clearing  abundances  canopy. the  reduce physical  I at Haines  were  a  however,  grazing  results  these  despite  crops,  so  possible.  macroalgae  showed  those that  effects  I a t each and  of the  a  escapes  site  di st ichus limits  macroalgae  F\_ d i s t i c h u s  biomass  factors  have  physical  stress  of  of  Secondary  and secondary  absence  species  the  desiccation  littorines i n the  Herbivores  summer.  littorine  that  1982,  s t r e s s , e t c . may  the  to  .  2  the combined  both  of both  were  on  i n Zone  suggest  enough  summer  n r  abundant  The  the  littorine  high  the  1000  effect  during  maximal.  a n d summer,  stress  small  that  The one e x c e p t i o n  during  exceeded  i t  reduced.  not  least  intertidal  standing  probably  and d e s i c c a t i o n / h e a t  However,  spring  were  the  observed  observed  of macroalgae.  months;  experiment  the upper  sites  3 ) , where  were  was m e a s u r a b l y the  only  However,  such  productivity  species  species.  spiralis,  studies,  and  but can l i m i t  on F u c u s  had only  winter  fucoids,  have  (1980)  densities  grazing  stresses  in  i n Zone  littorines  and Norton  of the p l a n t s  growth  certainly  during  the  be  that  (Geisselman  Schonbeck  these  littorine  almost  (see  grazing  on  appears  and ephemeral  that  rate  mechanism  perennial  a t the study  limit  this  on  of secondary  be  linear  I t thus  defense  increases in operating  from  grazing  to and  134 CHAPTER  Ecology the  has been  interactions  abundance  meant  a  quantitative and  communities there  examined  have  rocky  been  emersion  and h o r i z o n t a l  narrow  of  wide  sequences,  which  diversity  ( e . g.  in  a  short  advantages, intertidal 1977;  few  of  of  both  limits,  habitats.  Sousa,  1979b),  (five  to  ten  have  (Miller, to  gradients exposure  permitting  communities  I979ab).  in  1982).  tidal  a r e found  successional  the  species  "completed"  Despite  (Foreman,  have  the comparison  are generally  examined  1974),  studying  maintaining  years).  A  property  which  i s amenable  in  1971).  by P e e t ,  In a d d i t i o n ,  important  presence  this  studies  o f wave  this  by w h i c h i s  (Hurlburt,  Vertical  of and  in  species  communities  gradients  1978; S o u s a ,  Implicit  diversity,  field  system  study  distribution  (reviewed  of e n t i r e  workers  the  to quantify  few  diversity.  macroalgal  Lubchenco,  scientific  1978).  used  very  c a n be  time  "the  abundance  geographical range  MACROALGAE  of s p e c i e s  intertidal  of species  within  THE  ecosystems  patterns  a  (Krebs,  been  the d i v e r s i t y  The  as  measure  have and  OF  determine  relative  of i n d i c e s  however  that  i s the concept  (richness) number  defined  of organisms"  definition  of  5 - DIVERSITY  these  diversity 1977;  of  Neill,  135 Sousa in  (1979a),  California,  found  hypothesis  the  algal  assemblage  to  the  frequency  levels had and  of  little the  effect  on  intertidal the  of  and  in  that  of  The  succession  assemblage  disturbance  system,  algae  to  due  was  was  disturbed. high  Herbivores  their  them  of  related  maintained  to  "swamp"  (1979)  status  inter-patch diversity.  this  the  of  field  Huston's  diversity."  line  which  boulder  low  with  numbers  propagules  1979b).  Data  on  with  a  intertidal  supporting  species  along  intra-  ability  (Sousa,  of  frequencies  both  i n an  evidence  "general  Intermediate  working  the  macroalgal  standing  discussed analyses  in are  observed  species  assemblages  crop  this  richness  data  Multiple  performed  patterns  of  at  to  diversity  diversity  each  presented  chapter.  also  and  in  study  site,  Chapter  regression  assist to  in  of  based  3,  and  are  cluster  relating  various  the  the  environmental  factors.  Methods  (S,  and  Materials  Two  diversity  the  number  calculated (g  dry  wt"  on 1  the m" ) 2  indices, of  in addition  species  basis  of  presented  the  present algal  in Chapter  to  species  in  the  collections),  standing 3  richness  (Wilhm,  crop 1968;  data Peet,  136 1974), zone  were  of  the  used  to describe  study  1)  sites  2)  The  each  the  -  =  as  of  p(i=1)  proportion  of  sensitive  to  of  Type  index  II  and  rare  ( P e e t , . 1974) .  The  use  for  the  importance  estimating  species  in  analyses  (backward,  on  the  selected  were  algal  total  information  both  to  the  indices of  both  environmental  ...  1/q, +  where  p(i=s)  2  f o r by  species i .  is a  Type  while  more  I  for  index,  1/q  is  a  common  species  p r o v i d e s some  measure  the  assemblages.  Index,  biomass  species,  rare  and  Multiple  s t e p w i s e ; MIDAS) o f  abiotic  interval:  algal  exp(H'),  is sensitive of  of  each  where  +  2  accounted  Index,  presence  exp(H'),  Simpson's  the  Shannon-Weaver the  sampling  measure  + p(1=2)  2  site-zone-time collection  The  in  £_p(i)[logp(i)]  reciprocal q  =  =  assemblages  six-week  (1963)  expressed H'  algal  f o r each  Shannon-Weaver  content,  p(i)  the  S,  regression  exp(H'),  factors  common  and  (see Chapter  1/q 2)  performed. A  cluster  analysis  standing  crop  data  algorithm  was  using  a  Euclidean  Guire,  1976).  a  on  matrix  a was  polythetical  Only  distance those  "reduced" also  performed.  minimum measure  species  version  of  The  variance  biomass  cluster  procedure  (MIDAS:MINVAR;  whose  the  were  Fox  and  1%  or  137 greater  of  the  site-zone-time sampled  "working"  matrix  two  more  the of  the  algal  the rough t o p two  on  23  standing  1983  working meters  x 25  (16  July  and  and  analyzed  of  cm  values  of  the  Beale  heights (0.0625  was m ) 2  1983).  as d e s c r i b e d  presence  i n Chapter  "noise" thus to  1975).  a t Beale  during  chapter.  Because  are available  only f o r  transect.  quadrats  The  the  as opposed  not p o s s i b l e .  the transect during  15 A u g u s t  "reduction"  and Stephenson,  c o n d i t i o n s , data  a  rounded  a n a l y s i s was  in this  and  in  were  reduced  collected  the  site-zone-time  data  The  (Clifford  presented  resulted  crop  and  of  (Clifford  108  species  data  used This  i n each  more  and  matrix.  crop  or  This  analysis  is also  selected  meter  were  figures.  data  (dry weight)  i n two  species  absence  of t i d a l  each  zone  concurrent  estimation 25  found  e t a l . , 1982).  cluster  species  summer  the  of  biomass  In a d d i t i o n , s t a n d i n g  dependent  The  each  i n the o r i g i n a l  concurrent  and  significant  simplified present  in  1975; F i e l d  collections. to  algal  collection  quadrats  Stephenson,  off  total  both  were  accurate  Two  randomly  sampled  visits  samples 3.  An  were  to the  along site  collected  138 Results  Algal presented  standing in Table  Postelsia sp.  ,  species.  levels  The  collected of  two  were  well  each  largest  in the  with  site  values  sheltered  values sites  Nudibranch  and  diversity Nudibranch  S,  Zone  seasonal  general, were  and  at  these  I  fluctuations zonal  at Haines,  different  ,  Lower but  apparently  [exp(H')  no were  1/q  values  were  and  observed  I and  III at  assemblages.  Zone  i n the d i v e r s i t y  Helby,  patterns.  and S,  change II  II  of  at  showed  values.  patterns Wizard,  1/q  in  species  and Wizard  seasonal  at  Nudibranch. in  Helby,  The  found  seasonal  f o r Zones  1/q]  12-15.  were  Little  and  fluctuations  and  of the  3).  sp.  Figures  and  Zones  to that  Beale.  in  observed  by  , Hymenena  Chapter  diversity  III at Haines,  similar  showed  zones  are  "secondary"  similar  There  wider  the  spp.  area.  and W i z a r d .  in  dominated  Alaria  the lowest  and  was  by  exp(H')  was  f o r Beale  prominent  (see  are presented  comparatively  largest  this  (S)  Helby,  occurred  as  dominated  from  of  richness  In  were  data  Corallina  lar ix  I I , while  the d i v e r s i t y  studied  Nudibranch  made  I of Haines,  However,  the  ,  richness  Nudibranch/Zone Zone  area  distinguished  study  diversity  o f N_^_ l a r i x was  at  the shore  Species for  stature  and  The  Neorhodomela  collections only  23.  palmaeformis  and  plants  crop  and  of  while exp(H')  139 Table  23.  Macroalgal data  standing  f o r Cape  Beale  SPECIES  palmaeformis  Neorhodomela Hymenena  sp.  Corallina Iridaea  larix  Vancouveriens is  cordata  Corallina  officinalis  Note:  =  1983.  STANDING  CROP*  730.5  (485.2)  53.9  (115.3)  22.5  (38.0)  15.6  8.5  borealis  Polysiphonia  S exp(H) 1/q  summer  6.0  Microcladia  Prionitis  diversity  12.6  sp.  Endocladia  and  i n the  MEAN  Postelsia  Alaria  crop  1.9  sp.  0.3  muricata  0.3  lanceolata  0.3  =11 1.90 =1.35  * g dry  wt  m~  2  (standard  deviation)  F i g u r e 12  Species richness  and d i v e r s i t y  of  the i n t e r t i d a l macroalgae at Haines for  each six-week  sampling  A) S p e c i e s B) exp (H')  C) 1/q 9 = Zone I •  = Zone 11  A -  Zone  III  interval.  richness  141  A - Haines  •2  TP  ~~T~  Jn  S  N  Ja Month  1  M  —I Ap  My  ~1— Jn  A  Figure  Species richness the i n t e r t i d a l  13  and  diversity  of  macroalgae  at Helby  f o r each six-week sampling  interval.  A) S p e c i e s B) exp  (H')  C) 1/q  •  = Zone I  •  = Zone I I  A  = Zone I I I  richness  143  Month  Figure  IA  S p e c i e s r i c h n e s s and  diversity  of  the i n t e r t i d a l macroalgae at Wizard for  each six-week  sampling  A) S p e c i e s B) exp (H') C)  1/q  •  = Zone 1  •  = Zone II  A  = Zone I I I  interval.  richness  145  Figure  15  S p e c i e s r i c h n e s s and d i v e r s i t y intertidal  macroalgae at  f o r each six-week  Nudibranch  sampling  A) S p e c i e s B) exp (H') C) 1/q  •  = Zone 1  •  = Zone I I  A  = Zone I I I  of the  interval.  richness  147  Month  148 were  greatest  Nudibranch  for  I,  species  while  was  richness  II  i n Zone  the d i v e r s i t y  the sheltered  were  very  distichus values at  f o r Zone  Haines  while  at  Zone  II.  At  exceeded  that  in  in  III  indices  Wizard  II (range  were  generally  were  to  be  greatest  larger  1982  those  f o r spring-summer Diversity  from  the  fall  similar Haines  larger  i n Zone  and Helby,  Haines  similar however,  and  during  1983.  summer Species  summer  from  Diversity  12-a  at  i n June  at  and  greater at values  Values  o f 1/q  the  summer-  with Wizard,  while  Wizard. sites  increased  1982, a n d d e c r e a s e d richness  summer  to  and s p e c i e s  1982 a n d 1983  S and d i v e r s i t y  t o Zone  showed  and f o r the spring-summer  but S decreased  those  greater i n  exp(H')  and Helby.  I I I of the sheltered  Helby.  also  while  larger  with  than  Figures  I I I was  compared  1983 w e r e  at Wizard  also  I I I ; values during  a t Helby  t o summer  pattern  9;  Fucus  the d i v e r s i t y  higher  was  I and  of  14~a) c o m p a r e d  than  at Haines  1982 c o m p a r e d  the spring  richness  Zone  i n Zones  that  somewhat  and Helby,  i n Haines/Zone  fall  in  in  Haines  greater  were  however,  were  (no more  values  dominance  o f 8-15; F i g u r e  richness with  the  Note,  Species  and Helby  compared  tended  areas.  II at Wizard  Species  diversity  reflecting  and Helby.  at Haines  13-a).  sites,  low,  i n these  Wizard/Zone  at  greatest  sites,  Zone I . At  II  I I I of the s h e l t e r e d  diversity  Nudibranch, Zone  i n Zone  1983 e x c e e d e d  1983 a t  fall  1982  richness  Haines;  at that  a  were  Helby, i n June  149 1982, At  although  Wizard,  compared  in  seasonal  (Figure  15-bc);  were  richness  was  each  other;  in  while  S showed  recovery  and  1/q i n Z o n e  two  years.  are  and  presented  indicating  the  in  amount  summer  1983.  multiple  24. though  variability  April  i n June  was  a n d May  Decreases 1983, of  lower  with  exp(H')  than  similar  those  for  analyses  the  o f S,  environmental  factors  MULTIPLE-R  partial  significant,  species  and  are quite  f a c t o r s account in  species  parallelled  as w e l l .  regression  The  f o r Zone  the spring-summer  1983 w e r e  abiotic  was  declines in  Values  richness  1983  values f o r  those  between  observed  1/q  pattern  closely  increase  i n August  Table  II  and  1982, w h i l e  During  tripled  the environmental  of the  1982  a n d summer  I I , dramatic  the f a l l  were  species  i n exp(H')  1982, w h i l e  i n Zone  values  coefficients, that  similar.  I a n d I I I showed  and the d i v e r s i t y  constant.  1/q o n s e l e c t e d  correlation  small  of  were  richness  Zone  during  II during  1982, w h i l e  Results exp(H')  In  sizeable  apparent  Zones  the spring  the f a l l  parameters  some  summer  a  year  i n t h e summer  increases  during  parameters  diversity  a l l three  for  during  relatively  a l l three  in  richness  observed  1983,  greater  the species  slightly.  diversity  1983  though  observed  Species  increased  were  diversity  however,  III declined  f o r each  1983.  change,  were  as c l e a r .  Zone I  I  values  values  Nudibranch,  Zone  not  a l l three  t o t h e summer  At little  the August  low,  f o r only  richness  a  and  150 diversity. equations the  The  i s per cent  longer  species  summary  of  are presented  arbitrary  to group  comprehensible are  108  units.  certain  particular  identified. zone-times  1)  Haines/Zone  2)  Haines, Helby  and  of  I - spring  (Group  is  1975), but  collections  into  in Figure  groups,  16  although are  of the f o l l o w i n g  also site-  groups:  & summer  and Wizard/Zone  1983  significant  collections  separate  a  is a  significance  distinguished  f o r each  into  the  Stephenson,  1983  (Group  II - s p r i n g  B)  &  F)  3)  Nudibranch/Zone  II (Group  4)  Nudibranch/Zone  I I I (Group  Groups  with  level  of  The dendrogram  site-zone-season  are classified  the lower the  i n the form  site-zone-time  The c o l l e c t i o n s  remaining  various  16.  site-zone-month  summer  The  analysis,  The u n i t s  comprised of general  that  values.  The c h o s e n  the  of the  indicating  a r e exposed,  print-out,  (Clifford  i n a l l three  to a i r ,  in Figure  computer  distinguished.  somewhat seemed  assemblages  of the c l u s t e r  the  present  exposed  and d i v e r s i t y  results  dendrogram,  factor time  the algal  richness  The  groups  only  H) K)  (A,C,D,E,G,I,J)  were  combinations of the site-zone-time  composed  collections.  of  Table  24.  Multiple  regression  diversity  5 = 88.3  - 1 . 0 (H20-T) + 1.O(SAL) -  MULTIPLE-R Partial  = -0.04  MULTIPLE-R Partial  = 2.0  Partial  SE  =  richness  environmental  3.0(RAIN)  -  = . 26791 = -o. == - 0 ..43704 == - 0 . 30602 =• 63596 • -o. r == 0. 27710 r =• 381 10 • -o.  = 0.48074  P P P P .P P  + 0.04(SAL) SE  =  == == == == == ==  0 .0062 0 .0000 0 .0017 0..0000 0..0045 0..0001  -0.02(AIR  1.9  correlation coefficients: r r r  = 0.32541 = 0.37824 = -0.27488  - 0.09(N03)  = 0.39355  SE  -  P = 0.0007 P = 0.0001 P = 0.0043  O.OI(AIREXP)  =  1.4  correlation coefficients:  SALINITY N03 AIREXP  r r r  = 0.26929 = -0.24061 = -0.27538  and  factors.  0.5(VAR-H20-T)  7.7  r r r r  + 0.08(AIR-T)  + 0.2(SAL)  MULTIPLE-R  - 2.7(PFD) O.1(AIREXP)  species  correlation coefficients:  AIR-T SALINITY AIREXP  1/q  of  on s e l e c t e d a b i o t i c  = 0.69228  H20-T PFD RAIN VAR-H20-T SALINITY AIREXP  exp(H)  analyses  P = 0.0052 P = 0.0130 P = 0.0043  EXP)  152  F i g u r e 16  Summary of the c l u s t e r a n a l y s i s of the reduced s i t e - z o n e - t i m e biomass  matrix.  A - Haines/Zone 1, F a l l and Winter Wizard/Zone I, June 1982  K  B - H e l b y / Z o n e I, Summer 1982 Haines/Zone I, S p r i n g and Summer 1983 Haines/Zone I I I , Summer C - Haines/Zone I, S p r i n g and Summer 1983 Helby & Wizard/Zone I I , August 1983 D - Helby/Zone I , S p r i n g 1983 Haines & Wizard/Zone I I , Winter Wizard/Zone I I I , Summer Helby/Zone I I I , Summer 1982 E - Wizard/Zone I , S p r i n g 1983 Helby/Zone I I , W i n t e r and S p r i n g 1983 Helby & Wizard/Zone I , September 1982 F - Haines & Wizard/Zone I I , S p r i n g and Summer 1983 Helby/Zone I I I , Summer 1983 G - Nudibranch/Zone I , Summer 1982 Helby/Zone I , Winter Wizard/Zone I I I , S p r i n g 1983 Helby/Zone I I I , Summer 1982 H a i n e s , Helby & Wizard/Zone I I , March 1983 H - Nudibranch/Zone I I I - Haines/Zone I I I , Summer Wizard/Zone 111, F a l l 1982 J - Nudibranch/Zone I , W i n t e r and Summer 1983 Helby/Zone I I I , November 1982 and A p r i l 1983 Haines/Zone I I I , May 1983 K - Nudibranch/Zone I I I  154 Discussion  The  results  validate study  the o r i g i n a l site  clearly  exposure  on  effects  general,  the spring  Haines,  Helby  the  site-zone-time  The  algal  reflecting  cluster  Nudibranch/Zone so  that  in  F\_ d i s t i c h u s  I a n d Zone  the c l a s s i f i c a t i o n  Neill  standing  (1977)  on b i o m a s s )  has  observed  in this  high  on  shore  the  reported  study. were  from  the other  1983  period  sites  in  d istichus  in  due t o  both  and Wizard, similarities  assemblages.  v a l u e s and p a t t e r n s  At  which  protected  dominated  the  (e. g.  at  Helby,  and  various  species  abundant  Spain  In  I and II a t  together  secondary  i n these  t o some  C and F, F i g u r e 1 6 ) .  i s not s o l e l y  f o r northwest  those  f o r Zones  I I I of Haines,  crop  III  macroalgae.  of Fucus  fairly  is  a n d wave  I I I of the s h e l t e r e d  classified  were  the  (Groups  However,  spp.)  height,  distinguished  the importance  analysis.  Cladophora  (based  i n Zone were  of  II and  shows,  The spring-summer  separated  assemblages  also  each  This  Zones  tidal  periods  were  collections. also  where  16)  at  zones.  The a n a l y s i s  crops  (Figure  intertidal  respective  a n d summer  I  the  season,  standing  Nudibranch/Zone groups,  of  and Wizard  were  of  analysis  f o r Nudibranch,  distinguished.  the  cluster  their  evident  extent,  collections  the  division  into  particularly are  of  by  were  similar  sites,  fucoids  o f H'  (  to  areas Pelvetia  155 canaliculata  and  Fucus  spiralis  [exp(H*)  =  1.0].  These  and  Haines,  Helby,  on  II  at  the  more (L.)  shore  S.F.  sites  Gray.  exp(H')  =  year  dependent  III  assemblages  to  the  H^  diversity  of  at  values  r i c h n e s s and  near  Bamfield  substratum,  on  per  algal  increasing  herbivores Ulva  ,  Thus,  diversity  was  period  in  studied  cent  exp(H')  reflecting assemblages.  the  (H',  I and  data,  of  at  elongata between the  The  to  be  Zone similar  although  the  -  h e r b i v o r y on  on  per  The  a  of  to  On  those  fashion  littorea  .  algae,  such  dominated  did  the  H',  emergent  linear  ephemeral  the  cover)  values  4.1]. in  cent  similar  P o l y s i p h o n i a , but  not area,  The as  graze and  1.01-1.20].  1/q  Diversity  of  Littorina  eventually  dominance  Spain,  were  1.0  grazed  II  level)  .  I  levels  throughout  appear  England.  decreased  and  Zones  ranged  elongata  based  diversity  =  zero  lower  Himanthalia  impact  . =  [exp(H')  to  tidal  changes  in  [exp(H')  fucoids  Spain,  sites  the  cover  , and  similar  zone  H_;_  near  Spain.  New  density  low  Zones  in  diversity  Enteromorpha  Both  higher  in  by  numerous of  was  spring  this  sheltered  preferentially  fucoids.  in  dominance  algae  based  lower  communities  were  In  dominated  with  the  (1978)  though  with  the  elongata  intertidal  above  H'  were  Wizard.  Diversity  on  Lubchenco species  and  were  2.7-20.0,  and  assemblages  (+0.3-0.6 m  exposed  )  were  at of and  low  Haines,  throughout Helby,  F\_ d i s t i c h u s species  the  and  Wizard,  i n these  richness  study  were  algal also  156 greater  in  intertidal  Wizard/Zone areas  fluctuations to  the  the  in  stable  presence  (Figures  canopy, etc.  Late for The  diversity  values  secondary  and/or  substratum  retain  seasonal  during  heights.  during  in  of  in  species the  fall  suggesting governing  less  species,  Zone  and  diversity  Zone  physiological stresses  10%  living of  s t r e s s were  in  the  this time  fall  during  of zone (Table  infrequent.  more  was  and  tidal  permitted therefore  species  that  occurrence  daytime  12-14). in  were  year.  and  (Figures  decreased  the  the  14-15).  i s minimal  diversity  of  observed  (Figures  lower  during  diversity  III  were  action  the  and  time  I  and  the  than  to  conditions  sites,  out).  1982  Plants  physiological  due  depressions,  conditions  wave  chance  F\_ d i s t i c h u s  (shallow  that  that  reproduction,  in d i v e r s i t y  greater  this  to  the  Nudibranch/Zone  contrast  suggest  due  goes  upper  variable  in  12-14), was  tide  when  richness  zones,  availability,  the  other  and  affecting  summer,  during  sheltered  assemblage. air  (Figure  indicate  the  these  heterogeneity  and  secondary  greatest  sites,  in  the  large  species  when  rigorous  greater the  II  stress  Less  growth  were  1983,  water  changes  desiccation  At  habitat  with  The  fluctuations  Wizard/Zone  slightly  12-14).  summer-fall, increases  stressful  the  compared  richness  of  and  which  as  species  environmental recruitment,  II  At III  the  richness a l l  increased  spring-summer  were  important  macroalgae were 3);  three  in  exposed thus  However,  this  to  the  periods the  of  algae  157 that  live  in this  short  amounts  of time;  temperature, during these in  plants  i n Zone  lowest  during  wave  action  was  pattern  with  high  low  may  have  as  been  very  harmful  diversity  and  the f a l l  that  (Figure  (Table  wave  1).  action  The  was  preventing  the development  wave  physiological  exposure  filamentous  was  and  occurred to  also  1 9 8 3 , when  recorded  seasonal  in  limiting  II a l g a l  assemblage. canopy  and  action  -enabled  the  community;  however,  high  apparently  structurally  spring  important  wave  turf"  were  Diversity  of a F^ d i s t ichus  stress,  "algal  richness 15).  1982 a n d e a r l y  By  the  a i r  Vancouveriensis  species  of the Nudibranch/Zone  of  and  (such  development  development  sunlight  tides  the  reducing  stress for  Chapter 3 ) .  greatest  suggests  high  in Corallina  II at Nudibranch  was  tolerate  of  ( e . g. t h e d e c l i n e  highest  observed  only  periods  summer),  I I I at Haines;  The  could  concurrent  the e a r l y  Zone  zone  destructive  simple  algae  to  present  the i n the  zone. Exp(H*) and  i s plotted against  physiological  consideration) subjective Chapter  in Figure  ratings  2).  stress  Physiological  from  1 t o 4, a n d i n c r e a s e s  is  also  assumed  physiological  (desiccation  17.  made  that  disturbance  Wave  at  stress with  being  exposure  each  study is  (wave  s t r e s s at comparable  wave tidal  the  i s based  site  major  on  (see Table  subjectively  increasing tidal  as  exposure)  exposure heights  the 1,  ranked  height.  It  increases, i s  reduced  Figure  Plot  o f exp (H')  17  against  wave  exposure and d e s i c c a t i o n s t r e s s .  A - H a i n e s , H e l b y & Wizard/Zone I Haines & Helby/Zone I I B - Wizard/Zone I I C - Nudibranch/Zone I D - H a i n e s , H e l b y and Wizard/Zone I I I E - Nudibranch/Zone I I I F - Nudibranch/Zone I I , Summer G - N u d i b r a n c h , Zone I I , F a l l and H - Beale  Spring  160 (Stephenson and  Stephenson,  Demetropoulous, With  that is  and  the  the  best  hypothesis  of  in  effects  Waves  as  species  F.  barnacles, Further the  roles  etc.),  of  and  prevented environmental at  competitive  displacement  and  is  plant  presence  the  most  a  importance. assessing needed  to  of  the  E\  distichus  communities  competitive  population Diversity  algal  at  a  are  exclusion  i s dependent  high  occur.  rate,  i s low.  the  rate  Conditions  which  in  reductions  displacement  diversity  where  of  evidence.  that  occurs  and  (crevices,  are  results  and  stress.  biomass  secondary  the  the  physiological  The  herbivory,  supportive  community  low.  of  programs  by  desiccation  heterogeneity  However,  competitive  communities  caused  alleviate  are  and  assumes  displacement  as  17)  "general  including manipulations  fluctuations.  approached in  are  (Figure  (1979)  macroalgae.  periodic  which  and  also  c o n d i t i o n , where  by  Jones  hypothesized  diversity  limiting  herbivory  sampling  (1979)  1968;  is  Huston's  substratum  hypothesis.  non-equilibrium  higher  but  intertidal  experiment  Huston  of  action  competition  this  clearing  is  wave  canopy,  invertebrate  rates  of  species  disturbance,  by  1964,  it  diversity",  experimentation,  confirm and  a  faced  d i st ichus  of  light  distributions,  stresses  available,  species  interactive act  data  pattern  explained  Lewis,  1968).  limited  observed  1949;  a is  and  on  the Where  equilibrium Diversity  of enhance  is  competitive the  growth  161 rate  of  a  should or  few  species  reduce  diversity,  i n c r e a s e d where Fucus  Zones  and  was  very  low.  in  the  results  by  20),  appear  zones.  these  the  with  F^  harsh  physical  but  study Zones  I and  present ephemeral  to  zone  Leathesia  di fformis  americanum  , Cladophora  dominate to  the  have sessile  was  a  large  in  Nudibranch/Zone  as  clearing  i t was  seem  occurring The  stable  limited  diversity more  species  to  stress  benign found  in  only  abundance  (e.  g.  spp.),  none  of  Competitive so  between  I I I , many  other  of  growth  Zone  III  of  sporadically The  growing  of  the in  algae annual,  fenestrata, , Halosaccion  were  displacements  the  the  low.  Ulva  was  in  relatively  the  which  diversity  percentage  year  important  here.  generally faster  than  conditions  and  was  seen  experiment  be  not  in  diversity  species,  C r y p t o s i p h o n i a woodi i  minimal,  H.  and  Environmental  did  species  assemblage.  been  Wizard  thus  were  ,  assemblages  the  some  epiphytic  maintained  r i g o r o u s , throughout  algal  those  grew  this  and  .  conditions apparently so  be  physiological  themselves).  thus  II  in  but  c o n d i t i o n s were  sites;  by  distichus  (unless  F_j_ d i s t i c h u s ,  Physical  and  secondary  more  Competition  species  algal  F\_ d i s t i c h u s  limited  assemblages  secondary  all  of  the  of  will  ability)  lower.  Helby,  abundance  generally stable,  these  rates are  Haines,  competitive  diversity  dominated  at  The  competition  were  in  II  increasing  while  growth  dist ichus  I  (Table  (thus  high.  total  s p e c i e s were  algal also  able  to  appeared Although biomass able  to  162 grow  there.  assemblage  Diversity  was  wave  physiological  action  s t r e s s but a l s o  of  the algae  (note  N.  l a rix  The p l a n t s  ). and  a  distribution  this  turf  high  in  Nudibranch the stature  cases  of  are distributed  of intermingled  i s probably  the result  development  o f more  of  competitive  displacement;  this  extensive  reduces  and  F_;_ d i s t i c h u s  i n a mosaic  filaments.  o f wave  growth  diversity  biomass  of  The  shock  and small  patchy  preventing  and l i m i t i n g i s thus  very  stress  is  rates high i n  zone. At  low,  Beale,  the  Paine,  disturbance The major  degree  ,  is  1979). are high,  effects  (Stephenson  distribution  habitats  1977;  a n d Menge,  determined  also  important  water  and  1978).  abundance  is  often  a  size  and low .  cited  as  communities 1954;  a l . , 1968; D a y t o n ,  1971;  (1975) species  limited by  (Dayton,  and Orton,  Connell of  been  intertidal  to extremes  usually  and p o p u l a t i o n  et  site  displacement  1949; S o u t h w a r d  Ricketts  Mytilus  is relatively  have  the s t r u c t u r e of  by t o l e r a n c e s  species  motion  t o many  with  at this  diversity  probably  is limiting  of competitive  so t h a t  of  exposure  particularly  and Stephenson,  1968,  Lubchenco  a  o f wave  Rates  i n f l u e n c e s on  Lewis,  physiological  Competition,  c a l i forn ianus 1971;  although  high  species.  but  at  limits  i n the  the  this  comparatively  also.  Increased  patches  thus  stated are  that "the ultimately  of p h y s i c a l c o n d i t i o n s , to a  smaller  interactions  range of  with  other  163  organisms." limited and  In  importance,  annual  appear  species.  as  also  themselves  Algal  by  the  canopy  P. p a l m a e f o r m i s  physical  H^  turf"  a  desiccation correlation  This  between  factors  and d i v e r s i t y  (Table  24; s e e a l s o  presented  in  species  (the  combined an  with  the effects  resemblance  The area  differs  usually has  results  in  many  associated  with  been  intertidal 1966;  community  structure  1971;  1981).  Menge  abiotic  "algal  for algal  presence  algae  other  "algal  may  have  a r e exposed  physical  suggest  the  important  on W a s h i n g t o n  has been  algal turf"),  produced which  has  Bamfield  intertidal  Northwest. very  crop  environment.  that  those  analysis  standing  of  the  action,  a  environmental  regression  and S u t h e r l a n d ,  Competition  the  so  t h e low  Pacific  having  shock,  explain  from  as  wave  and  also  the  stressed  Dayton,  Lubchenco,  the  stress  in part,  canopy,  ways  the  reduces  The  study  Thus  which  t o the measured  of t h i s  algae  form  o f wave  which  the  growth  the regressions 3).  environment.  presence;  multiple  F^ dist ichus  to  reduce  selected  i n the  Chapter  environment  little  the  abundances  (1975),  in their  may,  and  desiccation  self-reinforeing stress.  secondary  environment.  sessile  s p e c i e s can survive  to  by t h e p h y s i c a l  reduces  and  restricted  Connell  additional is  h e r b i v o r y s e e m s t o be o f  distributions  largely  noted  alter  d i s t ichus  area  and c o m p e t i t i o n  t o be c o n t r o l l e d  However,  F.  the Bamfield  found  shores  shores  Predation role in (Paine,  1976; Menge a n d to occur  only  164 sporadically differences  due  observed  differences studied. almost and  Helby  little  of and  Northwest  1975) h a v e  The  Bamfield a  series  studied  by  in relation  exposure  a t the  study  of  intertidal  studies to other  presented  of the i n t e r t i d a l  communities role  habitats  a r e needed  algal  of  ( e . g.  probably  ecologists.  in this  coast,  species  intertidal  are  organism.  the  though  to  sites  sites  intertidal  intertidal  marine  due  the Washington  secondary  area,  The  part  a l l but ignored  i n t e r a c t i o n s with  the hypotheses  organisation  than  pressure.  in large  Wizard  i s the dominant  and e x p e r i m e n t a l area  wave  protected  Pacific  represents  this  examine  and  1971).  descriptive  the  of  Nassichuk,  been  place  more  predation  are probably  The H a i n e s ,  F_j_ d i s t i c h u s  unique, have  here  high  degree  d i st ichus  Dayton,  the  the  studies  (except F.  in  certainly  thus  Past  to  not which  Further  to properly areas  chapter community.  and t o  regarding  165 CHAPTER  It very  productive  oceans's  may  the  systems  to  (such  (1979), the  Chapman and  with  proposed  productivity  they  macroalgal  the  most  that  of  occupy  only  Mann  (1973)  forests  the  0.1% o f stated  communities  productive  rain  budgets  have  (Johnston  (Hatcher  et  and L i n d l e y  productivity and C r a i g i e  storage  of  (1977, (1982)  of  is  terrestrial and  managed  conditions,  et  (1981),  1978),  a l . ,  1977)  of et  for and  information,  Gerard  species  a n d Mann  information Laminar i a . a l .  (1981),  the relationships  between  nitrogen,  ambient  and p r o v i d e d  p a t t e r n s and magnitudes  This  provide  Anderson  examined and  determined  (I972a,b),  various  carbon  been  a l . , 1977).  t h e s t u d i e s o f Mann  a n d Chapman  environmental observed  macroalgae are  (1963)  of  tropical  sacchar ina  Gagne e t a l .  growth,  marine  phytoplankton.  of  carbon  lonqicruris  combined  though  MACROALGAE  crops).  Annual Laminar i a  as  that  Ryther  even  to  that  THE  f o r 10% o f t h e  productivity  agricultural  on  account  available  comparable  L.  plants.  phytoplankton,  area  that  P R O D U C T I V I T Y OF  i s g e n e r a l l y acknowledged  macroalgae  the  6 -  and  explanations  of Laminaria  f o r the  productivity.  166 Similar macroalgae which  have  comprehensive is  lacking.  combined  concurrent  al.  , Fucus  intertidal  crop  was  only  each  four  equivalent  to  species  on  an  were  intertidal  substrate  this  data  (Chapter  diurnal  photosynthesis  analyses  and were  3)  also  photosynthesis  (mg  with  C  with  calculate  studied of  the  Ascophyllum .  Littler  of  a  et  rocky  California,  but  the  and  standing  year  cover.  by  that  the  photosynthesis  rates  to  C  the  standing with  obtain  abiotic  they  rrr  fixed percent  2  of  species.  combined  g  they  addition,  ( i . e . mg  the  i n an  assumed  In  applicable  crop  of  Multiple  attempt  (per  sampling  measurements  estimates  dry  productivity  selected  crops to  lactuca  productivity.  performed  population/community substrate)  to  studies  southern  basis  from  was  annual  Ulva  assuming  occupied  few  standing  productivity  cent  area  program  monthly,  in  directly  study,  very  populations  during  productivity  intertidal  photosynthesis  the  per  been  algal  , and  on  times  of  (1977a,b,c)  community  thallus)  In  of  vesiculosus  reported  have  of  salt-marsh  algal  calculated for  of  (1979)  sampled  estimates  Brinkhuis  productivity nodosum  There  measurements  productivity.  knowledge  to wt" m  environmental  daily,  regression  relate d" )  1  2  of  1  of  daily and  intertidal  factors.  167 Definition  A  of  Terms  major  studies  has  problem  been  the  "productivity" sometimes interpret  the  confusion my  (1965),  to  the  will  sampled  or  harvested  area  (units:  the  primary  production  created  by  a  given  be  viewed  below  for  primary rate  of  trophic  In  what  order  to  presentation  and  terms,  mass  of  by g  normal  dry  —  organic  wt  is  any  to such  interpretation as  per  of  Westlake  the  mass or  the  of  in terms  of  net  and  gross  gross  productivity — energy  (units:  any  the  C  nr  rate  this  Primary  time  be from  of  primary first  day" ); 1  material  represents, production  production,  the 2  one  can  organic  productivity (units:  into g  new  energy  time.  and  at  that  2  one  level  i t  rrr );  any  of  words  and  minimize  material  methods  at  flow  the  measured  defined  area  net  to  was  photosynthesis,  unit  given  used:  crop  given  meanings  productivity  understand  the  standing  a  —  primary  Consequently,  following  be  previous  "production".  results.  regarding  data,  various  and  difficult  in  g  as C  in  must  defined  nr ); 2  production. (producer,  The  plant)  168 gross  productivity  material  —  or f i x a t i o n  the rate  of energy,  lost  as the r e s u l t  of  net  productivity  —  the rate  or stored  energy.  organic  material  or  (1946)  productivity discusses  in  their  symbolism  productivity  using  of accumulation In  energy  presents  based  extension  The  that  organic  subsequently  terms  of  available  o f new  organic  production,  the  f o r u s e by t h e n e x t  level.  Clarke  an  including  o f new  respiration;  material  trophic  of production  on  applications.  and w i t h of marine  1)  Gross  2)  Net primary  The  and  mean  following  modelling rates  equations  and are  equations  with  some  changes  particular  reference  to  the  primary  macroalgae.. productivity  two e q u a t i o n s  primary  of equations  (1946)  and net primary  the following  series  instantaneous  of C l a r k e ' s  gross  a  estimated  :  productivity  productivity  c a n be  = GPP  = SC  (GPS)  = NPP  = SC  (NPS)  =  (GPS -  SC  R)  169  where:  SC = s t a n d i n g = rate  of gross  NPS  = rate  of net photosynthesis  The  herbivory,  erosion  PSC(t=i)  productivity  4)  NPP  "the  (t=i),  of t i s s u e s ,  =  =  (mg C g d r y w t "  1  1  h" ) 1  h" )  1  1  (PSC) a t t h e end o f assuming  h" )  1  no  some  losses  e t c . , c a n be  to  calculated  SC(t=0){e[exp(GPS-R)t]}  over  the time  [PSC(t=i)  -  i s essentially  total  e l a b o r a t i o n o f new  unit  time,  the end of t h a t  ( t = i )t o (t=0) i s  the "production"  irrespective time."  interval  SC(t=0)]/t  This  during to  wave  to  2  C g d r y wt"  (mg C g d r y w t "  crop  irr )  equation ( 3 ) :  3)  Net  standing  (t=0)  ( g d r y wt  photosynthesis(mg  of r e s p i r a t i o n  potential  interval  using  of macroalgae  GPS  R = rate  time  crop  body  of Ricker  substance  of whether  in  (1958): a  stock  or not i t s u r v i v e s  170  The etc.  losses  of  plant  biomass (LOS)  due  to h e r b i v o r y ,  , can then be estimated using equation ( 5 ) :  5)  LOS  = (DOM  + HER  + OTH)  = PSC(t=i)  -  SC(t=i)  where:  DOM  = l o s s / e x c r e t i o n of d i s s o l v e d organic  HER  = l o s s of p l a n t p r o d u c t i o n to h e r b i v o r e s  OTH  = l o s s of p l a n t m a t e r i a l due  matter  to other  causes  (e. g. wave e r o s i o n of t i s s u e s ) LOS  = total  l o s s of f i x e d carbon/energy  that due  The procedures estimate (DOM,  HER,  of  or  to r e s p i r a t o r y metabolism  in  this  study  term.  provide  an  term, but not f o r the i n d i v i d u a l terms  which c o n t r i b u t e to the LOS  (3), (4) and  term.  (5) should be i n u n i t s  (5)  will  give  a  The of  terms carbon  rough estimate of the  C o n s i d e r i n g the l a r g e v a r i a b i l i t y  standing  crop,  photosynthetic  i s somewhat l i m i t e d . estimate  of  the  i n the  rates,  imprecise method of c a l c u l a t i n g the LOS  an  can  energy. Equation  of  the LOS  OTH)  in equations  used  excluding  term,  LOS  measurement  and  the rather  its  accuracy  However, i t should be p o s s i b l e to make magnitude of t h i s term and compare i t  with other p r o p e r t i e s of the system.  171 Methods  and  Materials  Productivity using  the  standing  measurements  of  Rates  of  oxygen  evolution  performed  (  experiments  taken  needed,  were  were  found  experiments.  ,  in  to ensure with  Apical  of at least  quantities Only  sections four  1972;  Rates of distichus  for additional larix  ,  warranted. photosynthesis during  the  Additional  plants  were  material  Helby of  the  wave  were  Fucus  d i c h o t o m i e s , were  at The  and Nudibranch,  thalli of  for  replication.  of a l l species  healthy  the  collected  suitable  representative  there.  Fucus  the  enough  from  as  experiments  Neorhodomela  the algae  only  for  abundances  program.  collected  and s u i t a b l e  consisting  from  using  Parsons,  sporadically  used  2-h i n c u b a t i o n s  sites  be  and  material  measured  of macroalgae.  monthly  difformis  sampling  when  four  gradient could  was  crop  collected,  these  sessile  plant  used  determined  were  and  3 and  respiration.  photosynthesis  species  spp., e t c . ) as t h e i r  The  algae  were  and  respectively,  (Strickland  selected  calculated  i n Chapter  respiration  Diurnal  Leathesia  Cladophora  standing  method  on  Hedophyllum  species  photosynthesis and  was  presented  depletion,  1974).  photosynthesis  least  and  macroalgae  data  diurnal  bottle  Vollenweider,  and  crop  photosynthesis  light:dark  were  of i n t e r t i d a l  as  exposure of  used  interest in  the  distichus c u t from  ,  whole  172 plants;  such  pieces  plants  and  included blade  thalli  were  H. (  sessile Ulva  whole  were  from  the  .  For  a l l  branches  used  collected  at  The and  algae  cleaned  of  Marine  Station.  comparable less were in  than  15%  I. 0  ml g  Cryptosiphonia  ( Cladophora  each  case, as  ) ,  spp.)  the  plant  p o s s i b l e of  that  prepared the  The  greenhouse  as  ambient  any  had  air  1977;  previous  to  the  were at  maintained  the  Bamfield  duration)  The  filtered  water  (from  were  20  troughs m  depth  (for mixing).  possible the  size  greenhouse  seawater  on  to  and  sunlight.  bubbled  have  (PFD  the  urn f i l t e r e d  (Hatcher,  plants  conditions  reduced  day  ( i . e . cut  effects  This  cutting  photosynthetic  Dromgoole,  1978;  rate  Littler  and  1980).  The 300  and  in a  and  have  might  determinations Arnold,  the 45  clumps  In  in nature,  Inlet)  should  plants  ,  or  plants  site.  Light  with  Bamfield  vancouveriensis ),  of of  d i ff ormis  representative  troughs  of  meristem,  ,  epiphytes)  those  equipped  treatment the  to  Sections  amer i c a n u m  experiments.  i n water  the  whole  whole  collected  most  to  of  species, either  l a rix  study  were  photosynthesis overnight  other  as  portions.  distal  possible.  was  the  stipe  blade,  ( Corallina  whenever  material  and  , Halosaccion  , Neorhodomela  used  generally representative  cut  fenestrata  woodi i  were  algae  were  BOD  bottles  dry  wt  cut  used  so in  that the  Johnston  algal  concentrations  experiments  (1969)  found  did that  not the  use  in  the  exceed of  up  173 to  0.3  g  in  duration  carbon  dry  wt  algae  did  not  that  bottles  would  the  environmental  alter  depend  (1975)  ca.  liter  and  1 higher  of  Significant  Gardn.  Colpomenia  short  time  the to  stored  in  a  have  with  has  very  low  quantities any  measurements  the Ulva  l "  algal  resulted  1  observed  species lobata  Sol. The  use  (Kutz.)  , of  material  on  used.  rates  possible bottle  of  to  of  differences  and  plant  his  size  high  rate. of  explain  concentration  significant Derb.  very  limited  with  in  ambient  (1979)  algal  found  no  algae  or  expect,  and  not  h  for  which two  hour  in  this  effects  photosynthesis  and over  periods.  surface  remove  were  wt  24  algae  bottle  Littler and  would  used  could  dry  varied  (Roth)  small  seawater  algae  size  which  at  accurate  The the  and  should  provided  ,  sinuosa  incubations  he  to  nutrient  One  increasing  2 0 - 1 9 5 mg  were  to  up  enclosing  species  that  bottle  there  photosynthesizes  of  Although  photosynthesis  photosynthesis;  study  of  differences  and  the  found  due  bottles.  photosynthesis.  effects  measurement  on  using  r a t e s of  the  results  i n the  conditions.  Buesa  Setch.  the  in experiments  possible effects  results,  that  seawater  1  dioxide depletion  however,  in  l "  used  10-20  originated, larger  m  i n the  experiments  o f f s h o r e of filtered  phytoplankton,  polyethylene  the  through  was  study 45  site  urn N i t e x  zooplankton  carboys  collected  and  overnight.  from  from which  screening  debris, The  water  and was  174 shaken  at  intervals  dissolved The 0600  h  for  ca.  oxygen  14  performed 3-6  four  (until  running  throughout  dark  bottles  to  metabolism.  The  and  bottles,  dark  equaled min  by  gross placing  bottle ca.  the  on  begun  and  fall  bottles.  and  winter). were  set consisted Four  light  macroalgae)  plankton  measured  and  net  were  photosynthesis  sum  of  Mixing  was  provided  the  two  stirrers  magnetic  and  bacterial  the  magnetic  at  continued  incubations  dark  Teflon-coated  Instrument  titration  water  in  with  run  a  values  every  (each  stirring  The  Model oxygen  method  converted  Inlet.  Model  0260 O x y g e n meter  carbon  was  light  seawater 1°C  ±  Photon  LI-500  Oxygen  (Strickland to  natural  Flowing  Bamfield LICOR  under  temperatures  Corporation).  Beckman  Stirrer.  were  greenhouse.  water  measured  were  the  incubation  respiration;  bottles a  maintained  surface  a  the  winter)  (without  bottles  1979).  were  Each  for  equilibrate  (Littler,  two-hour  photosynthesis..  experiments  in  bottles  with  light  to  bar)  15 BOD for  minutes.  The table  two  and  during  of  correct  contained  1-2  and  use  experiments  sunset  day.  to  levels  fall  bottles  established  the  the  sets the  control  prior  atmospheric  (during  h  light  hour  photosynthesis  sunrise  Continuously  of  with  diurnal  or  f o r one  in  a  wet  around  the  that  flux  density  Integrator  equipped  calibrated  using  Parsons,  equivalents using  a  was  measured with  the  1972).  the  (Lambda  c o n c e n t r a t i o n was Analyzer  and  of  BOD  Winkler Values  photosynthetic  175 quotient 1.00  (PQ)  1.20  (Westlake,  plants  in each  aluminum  0.01  BOD  Net  reported  as  The  a l . ,  C  1979;  greater  accuracy  Diurnal  of  variance  species  and  for  massed and  (RQ)  of  1972).  separate,  The  labelled  at  least  to  the  respiration  48  h  in  a  nearest rates  are  Littler  and  h" . 1  is essentially  Murray, and  were  1974;  These  (2  that  of  Littler,  Arnold,  shorter  monthly  day)  however light  1979;  1980); h  vs  daily  Littler  however,  4-6  modifications  h)  and  allowed  the  diurnal for  productivity  differences  possible)  were they  Thus,  not  net  tested  much  (Ramus  were  of  photosynthesis using  Diurnal  identical  generally  the  tests  were  in  (UBC*GENLIN).  conditions  valid  differed  monthly  conditions  in  a l l  by  less  similar during  ANOVAs  analysis  the  months than  one  respective  performed  should  be  diurnal  differences  in  and  s.  appearance only  Parsons,  in  105°C  and  1  used  (where  of  incubations.  observed  wt"  techniques  photosynthesi  at  in determining  and  respiration  considered  placed  quotient  1980).  and  The  dry  examined.  Rosenberg,  and  g  periods  were  compared;  were  dried  Littler  changes  hour  S t r i c k l a n d and  oven,  (Littler  time  respiratory  photosynthesis  mg  incubation  a  bottle  methodology  co-workers  (i.e.  1963;  convection  g.  and  and  containers,  gravity  et  of  of  bubbles  occasionally,  with  very  and  high  in  the  generally rates  BOD only  of  bottles with  was  those  photosynthesis  176 (  fe n s t r a t a  from  those  with  the  , Cladophora  bottles  values  calculated  values  (this  occurred  saturation  adds  this  error  10%;  calculated  respiration,  the  mean  of  twenty-four adjusted  species  although  t h e oxygen was  levels  respiration noted  above may  have  (Tolbert,  a hyperbolic  and oxygen  Thus,  t e n s i o n and  those  the presented i n nature.  with rates  Although  calculations,  probably  quite  per g d r y weight  to  the l i m i t e d  Total  the  hourly  .  The  rate  analyses  photosynthesis  f o r each  appeared  f o r nighttime  respiration  the  small  e t a l . , 1977).  There  unfeasible.  oxygen  (1978)  one and  net photosynthesis f o r each  differed,  incubation  to the productivity  i s a conservative  experiment.  this  than  the  cases,  apparent  lower  i f  most  an  data  compared  and  In  respiration  an unknown e r r o r  Daily  bottles  further  elevated  in  were  any  concentration.  see Hatcher  appeared  The  in  Dromgoole  dark  in a l l probability  this  (<  between  ).  apparently  and enhanced  1979).  oxygen  of  These  reduction  increasing are  end  photosynthesis  linear  rates  rarely).  the  Littler,  bubbles  included  only at  N_;_ l a r i x  "bubble-free"  not  levels.  relationship a  from  were  concentration  1974;  i n which  photosynthesis  former  inhibited  spp. ,  daily  be  t h e mean  made  was  respiration  diurnal  respiration,  equalled  few d i u r n a l  respiration  changes i n tests  calculated rates  photosynthesis  assuming diurnal  was  photosynthesis  replication  diurnal summed  diurnal  of algae  that  of as  times was  the  night  respiration  rate.  177 Diurnal curve  photosynthesis  was  of photosynthesis  calculated  rates  vs  as the area  time  of  day  experiment.  E x t r a p o l a t i o n s t o s u n r i s e and sunset  assuming  the photosynthesis  last to  that  rates  incubations of the experiment,  s u n r i s e and sunset.  calculated daily  as  photon  net  flux  for  the  for  each  were  made  first  and  respectively,  Photosynthetic  daily  under t h e  efficiency  photosynthesis  f o r t h e d a y on w h i c h  continued (PSE)  divided  the  was  by  total  experiment  was  performed. Algal substrate using crop  productivity was c a l c u l a t e d  the equations and median  productivity provide crop  data  80%  of  the  carbohydrate, free  dry  1983). 550°C  wt  experiments  of annual  0.32; weights hours  daily  light for  longer  a  number  standing  to  then  estimate summed  Algal  dry  by  to  standing that  weight  1963; A t k i n s o n  was  and  ashSmith,  combustion  at  1971). encountered  periods:  conditions.  used  interval  (i.e. g C = g  determined  (Paine,  mean  were  was c a r b o n  were  intertidal  e q u i v a l e n t s assuming  photosynthesis  over  were  (organic)  Westlake,  were  The  these  to carbon  of  sampling  productivity.  ash-free  difficulties  productivity varying  intervals;  a n d 40% o f t h i s  f o r twelve  calculated  and  interval  plant's  x  six-week  f o r each  converted  Ash-free  Two  f o r each  meter  earlier.  between  were  square  presented  date  an e s t i m a t e  per  values those  The r e s u l t s of  the  when  algae  using  to  of t i d a l of the  the  estimate exposure PS  vs  (see Appendix  I A)  178 showed low  that  levels  photosynthesis (<200 uE  nr  was s" )  2  1  photosynthesizing  a t maximum  Light  might  limitation  self-shading)  and  in  plants  lower  easily  corrections  were  calculations. reduced  in  Chapter major  the  made  3  number daily  sampling  diurnal  to  in  Neorhodomela amount  factor  uE n r  vancouveriensis s~  2  and  1  standing  these  in  the  no  productivity  standing  with  not  crop,  crops  summer  were  1982 ( s e e  s e l f - s h a d i n g was p r o b a b l y  days  (cloud  see  Chapter  recorded.  H_j_ s e s s i l e  50%  that (except  overcast)  not  a  and  On  and  >50% a t 2 o f  2)  during  each  days,  daily  overcast  C^ v a n c o u v e r i e n s i s  of the values when  cover  c a l c u l a t e d from the  the experimental  corrections  was  were  days  made  in  were the  calculations accordingly.  Productivity was  that  was  experiments  productivity  C_^  in  compared  of o v e r c a s t  be  days.  d i s t i c h u s (due t o  and  350-450  be  d i st ichus p r o d u c t i v i t y .  interval  themselves  sites  for this  observations;  photosynthesis assumed  in  increase  1983  i n f l u e n c e on  should  on a l l b u t o v e r c a s t  I n a d d i t i o n , F\ d i s t i c h u s summer  fairly  i n F_;_ d i s t i c h u s was a p r o b l e m  from  3), suggesting  The  at  plants  at  on t h e s h o r e ) .  self-shading  separable  rates  saturated  the  IL s e s s i l e  saturated  Because  and  be o c c u r r i n g  (photosynthesis a r e found  generally  of Neorhodomela  calculated larix  .  of s t r u c t u r a l  using  Because material  larix the  of  at  data  the  the for  sheltered Nudibranch  apparently  in the t h a l l i  greater  of the sheltered  179 plants  (see  sheltered  N_;_  Nudibranch A  number  air  and  al.,  1974;  both  been  time may  as  F.  dist ichus  time  of  used  and  stress. daily  the  have  including  plants  are  et  a l . ,  levels  in  to  of  photosynthesis be  shown  E\  that  and  in  loss  is  ca.  at  respiration.  calculation  (Johnson a l . ,  resulted  in  of  et  1979).  decreased  These F^  results  di st ichus  follows:  I  plants  the  were  summer,  exposed  and  for  ca.  therefore,  photosynthesis.  calculated  daily  photosynthesis  during  months  of  the  productivity  2)  The  Zone  II  apparently  photosynthesis  suffered  fact, of  were  values  May  to  70-90%  of  desiccation Thus, for  August  values Zone  I  (inclusive)  calculations;  plants  corrections  underest imated;  greatest  25%  daily  productivity  the  ,  reduced  in  of  by  Quadir  water  that  the  photosynthesis  distichus  1976;  the  50%  of  basis).  desiccated  the  No  daily  weight  in  productivity; the  workers  Zone  have  50%  dry  photosynthesis  during  of  were  the  net  assumed  a  considered  1)  stress  of  Brinkhuis  productivity  the  (on  higher  of  3),  was  fucoids,  when  However,  have  l a r ix  plants  intertidal  rates  Chapter  when  were  exposed  ca.  only  limited  made  on  used  based  on  the  Zone  II  F\_  to  the  50%  the  desiccation calculated  estimate  above-mentioned di st ichus  of  may  net  long-term studies, have  been  180  3) of  the  daily  The  time,  Zone and  III plants thus  photosynthesis  The  other  lower  shore  desiccation; death.  studied  levels  and  standing  any  in  scope  finer  correction  factors  to  limitation  larix.  the  assumption  "split The  main  factors  the  studies  the e f f e c t s  that  rates,  for  i s to reduce  H.  to  affected  by  in  the  using  alga's  the d a i l y  stress  as  would  the  allow  and i n any  other  of  plants  C.  were  factors reduction  Littler  the possible  of  error  which  eta l . , a r e needed or  light-  Vancouveriensis, applied  based  were used  the productivity  application  case,  moving  and n u t r i e n t s  desiccation  sessile,  for  f o r t h e wide  of photosynthesis  these  in  not  account  (see  factors  a n d a 50%  difference"  reason  to the  calculations,  does  temperature,  The c o r r e c t i o n  photosynthetic  study  (due t o c l o u d s ,  i n F\_ d i s t i c h u s ,  and  10%  restricted  due t o d e s i c c a t i o n  to i n nature  Physiological evaluate  long-term  of t h i s  etc.),  a r e exposed  properly  when  possibly  column,  1979).  made  cannot  in  plants  resulted  to' be a p p l i e d ,  in sunlight  the  applied  little  factors  fluctuations the water  were  that  in productivity.  and d e t a i l  correction  were  the  crop  f o r any r e d u c t i o n  The  less  generally  usually  no c o r r e c t i o n s  decreases  were  apparently  stress  values  account  no c o r r e c t i o n s  species  photosynthesis in  exposed  values.  extreme  Thus,  were  on  reducing to  simply  calculations.  these  correction  i n the productivity  181 calculations  and,  i f possible,  t o make  the c a l c u l a t i o n s  more  conservative. In  order  productivity purposes  an  estimate  i n Zones I and  with  F.  distichus,  to  calculate  Zone  to obtain  the other U.  of  were  The  species  the photosynthesis  only  using  reported  other  species  ,  spp. ,  f o r these  approximations,  from  used  limitata  Polysiphonia  values  rough  data  II  data f o r  s p p . were  I Pelvetiopsis  Zone  productivity  are thus  calculated  Zone  and  macroalgal  ( f o r comparsion  f e n e s t r a t a , and C l a d o p h o r a  I Iridaea cornucupiae  latter  the t o t a l  II at Nudibranch  zones),  productivity  respectively.  of  as of  they  similar  morphology. Mulitiple MIDAS) gross  were  values  For  performed  abiotic used  with  daily  net  the d a i l y  interval  the  from  time  calculated  productivity factors  series  initial were  daily  net and  estimates  The  estimations  were  conducted.  the values six-week  used  on  3).  was  calculations, the  stepwise;  (see Chapter  the experiment  productivity  factors  (backwards,  photosynthesis  i n which  environmental in  and  the  environmental  f o r t h e month the  analyses  with  photosynthesis  selected  those  regression  of the sampling  i n the regression  analyses. Growth followed and those  by  of  sessi le  tagging  monitoring o f Mann  in  plants  blade  (1972b).  Zone  at  located adjacent  elongation Ten  III  plants  using were  Nudibranch  was  to the t r a n s e c t s  methods  tagged  on  similar 25  to  August  182 1982  a n d t e n on  until  22  September  prevented Ten  p l a n t s were  situ  entire  growth May  three  blade  holes; blade two  in thus,  blade value  Wet  by  examination.  an attempt  25%,  area  was  spring  1983.  1983  t h e two d a t a  is  5 cm  on e a c h above  larger  available  was made  intervals New  the  and sets,  for  an  h a s no s t i p e ) blades  to  blades a  thallus  a  cork  one  hole  had  three of  checked  at  of the holes  punched,  i f needed,  measured.  grown  the  variety  The p l a n t s were  were  of  with  had  include  and o l d holes  of  a n d o n e , two,  the juncture  a n d t h e movement  holes  new  plant  and wider  i n the study.  at  conditions  until  Between  ( i n width)  while  week  monitored  1983 a n d 20 May  sessile  and t h i n n e r  during  up and  Thus, the  a  time  obtained. area  ratios  measuring  twenty  Non-tagged  p l a n t s were  t h e l a b o r a t o r y where  0%,  selected  weight:surface  determined  summing  weather  sessile  (  of surface area was  1983.  punched  measured.  width  interval  to  holes  morphologies  blade  30 A p r i l  growth  period.  were  them  to four  the  adverse  for  holdfast  Small  punched  data  blades  1 cm  on  9 August  t o October  and  borer.  1982;  tagged  until  Three or  1982 a n d t h e i r  c o n t i n u a t i o n of the experiment  monitored in  8 September  50%,  75%  width  and  blades  collected  measured  at  100% o f t h e b l a d e  calculated  using  the  values.  four  was  (20)  of  the  formula  Wet:dry  for  weight  sesile  were  during  each  and r e t u r n e d intervals  length. a  of  Surface  rhombus  and  conversions  from  183 the  standing  dry  weight:surface  to  carbon  C  blade  made  using  The  loss  on  blade  holes  sampling area  equivalents  Rates mg  crop  of  analysis  had  described  of  tagged  size  as  as  been  a  are  in  values  expressed  were  time  obtain  converted  terms  intervals  techniques  as  were  (UBC*GENLIN).  performing  ( i . e . whether  the  to  in absolute  between  prevented  covariate  applied  previously.  variance  plants  punched  were  These  Comparisons  1  of  ratios.  elongation  day" .  - 1  program  one,  the  analysis  two  or  three  blade).  Results  The  ash-free  macroalgae, presented content Ulva  expressed  in Table were  of  Wizard  was  F=14.390 While  content  distinct  of  greatest  significant  analysis  l a rix  F\  (p<0.0l) groups.  g  intertidal  dry  amer i c a n u m  wt" , 1  in  organic  , Cladophora , and  the  are  spp.,  sheltered  .  March,  seasonal  did  wt  distichus  p=0.00000**;  distichus  selected  differences  F\_ d i s t i c h u s in  for  ash-free  Seasonal  , Halosacc ion  9,434df;  Nudibranch  g  for Fucus  Neorhodomela  Organic  weights  as  25.  found  fenestrata  morph  (organic)  April  Haines, and  S-N-K  May  7,46df;  divide  Helby 1983  analysis,  d i f f e r e n c e s were  (F=4.4417 not  at  the  also  (ANOVA: p<0.0l).  found  p=0.00077), months  and  into  for S-N-K very  Table 25.  Ash-free ( o r g a n i c ) dry weight  (g AFW  g DRY  WT-1)  macroalgae during each six-week sampling  SPECIES  JUN  AUG  SEP  NOV  APR -  Cladophora spp.*  0 . 47 1 0 .458  0 .433  -  C. V a n c o u v e r i e n s i s  0 . 332  0 . 263  0 . 240  0 . 289  for selected interval.  MAY  JUN  AUG  0 . 367  0 . 391  0 . 420  0 .431  0..271  0 . 297  0 . 283  0.. 273 0 . 264  MEAN  C. woodi i  0., 46  E. muricata  0.. 75  F. d i s t i c h u s ( 1 ) *  0 .773  0 . 772  0 .779  0., 785 0. 805  0..815  0.. 768  0 . 766  0.. 782  F. d i s t i c h u s ( 2 ) *  0 . 791  0..807  0.. 764  0.. 732 0. 753  0.. 770  0. 775  0.. 780  0. 774  H. americanum *  0.. 567 0..690  0 .684  0. 776  0. 563  0.. 596  0. 573  0..623  0. 647  H. sess i1e  0..652  0..697  0. 707  0. 683  0. 654  0. 662  0. 677  0. 672  0..673  I. cornucopiae  0. 73  L. di fformi s  0. 347  N. l a r i x  ( 1 )*  0. 550  0. 481  0. 477  0. 783  0. 865  0. 913  0. 862  0. 864  0. 695  N. l a r i x  (2)  0. 696  0. 658  0. 650  0. 670  -  0. 625  0. 648  -  0. 660 0. 78  P. 1i mi t a t a Polysiphonia  0. 55  spp.  U. f e n e s t r a t a *  0. 614  0. 681  0. 709  -  0. 647  Note: (1) P l a n t s c o l l e c t e d from Haines, Helby and Wizard (2) Plants c o l l e c t e d from Nudibranch * S i g n i f c a n t d i f f e r e n c e s between months (ANOVA) Fucus d i s t i c h u s  (1) JAN  1983 = 0.757, MAR  1983=0.794  0. 595  0. 632  0. 614  0. 643  185 Analysis organic  of  variance  weight  of  significant  (F=4.2365  results  the  of  organic  weight  1982.  Organic  was  6,l37df;  content  analysis,  p<0.0l).  In  species,  organic  content  was  lowest  7,49df;  during  including diurnal  26 time  list of  di st ichus  diurnal  from  I8a-c.  those  obtained. daily  The  respiration analyses  respiration are  shown  given  variance by  month,  presented  of zone,  F^ and  in Table  N^  1982  net  Table  are  daily  (F=67.231  conditions, day  on  which  for  Fucus  presented  and  the  27.  of  of  a l l  P/R  ratios,  mean  diurnal  Results  of  photosynthesis day  in  photosynthesis,  diurnal  dist ichus time  larix  performed.  Helby  and  28.  of  representative  (PSE),  (S-N-K  secondary  photosynthesis  are  daily  in  1982  other  f o r each  at  C a l c u l a t i o n s of  7,57df;  p = 0 . 0 0 0 0 8 )  November  were  II  clear,  p<0.0l).  sunset,  net  the  September  6,70df;  meteorological  and  efficiency  and  September  experiments  curves  rate are  of  and  of  very  s h e l t e r e d morph  general  I  not  (F=9.3581  the  analysis,  respiration,  photosynthetic  only),  August  curves  Zones  Figure  the  s u n r i s e and  photosynthesis  Selected  total  of  with  the  statistically  August  and  in  Although  were  (F=5.6663  contrast  June,  was  americanum  September  p = 0 . 0 0 0 0 0 * * ; . S-N-K  Table  (p<0.0l)  in  i n August,  spp.  in June,  fenestrata  greatest  differences  p=0.00061).  analysis  greatest  p=0.00000) and  monthly  Cladophora  S-N-K was  for  the and  (photosynthesis  Table  26.  Summary o f diurnal  DATE  LIGHT(1)  meteorological  AIR(2)  JUN JUN JUN JUL AUG AUG SEP SEP SEP OCT OCT NOV NOV  1982 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982 1982  29. 6 30. 5 22 . 9 28 . 2 40. 1 38 . 0 31 . 8 1 1 9. 8. 6 10. 4 16 . 6 9 .6 8 . •3  14 . 8 - 1 9 15 . 0 - 1 9 14 . 0 - 1 9 15 . 0 - 1 8 16 . 2 - 2 3 12 . 9 - 2 4 13 . 8 - 2 4 14 . 0 - 1 6 13 . 0 - 1 5 8 .0-11 4 .0-14 0 .. 2 - 6 5,. 7 - 8  15 9 6 16 20 18 28 27 29 13 24 12 24  JAN FEB MAR APR APR MAY MAY JUN JUN JUL JUL AUG AUG  1983 1983 1983 1983 1983 1983 1983 1983 1983 1983 1983 1983 1983  5. 1 2.2 12. 2 34 . 4 14 . 8 NA NA NA 33. 5 NA 41 . 6 38 . 0 13. 1  3.. 6 - 7 .8 5.. 0 - 8 . 0 7 .. 4 - 1 3 ' .. 2 6 . 1 - 1 8 . .8 9 . 8 - 1 2 ..0 1 0 . 9 - 17 . 3 16 . 2 - 2 8 . 2 14 . 0 - 1 6 . 0 14 . 2 - 15 . 0 13. 0 - 1 7 . 1 14 . 7 - 1 9 . 4 16 . 0 - 2 0 . 3 13 . 8 - 1 6 . 0  (1) (2) *  E m-2 'C Total  on  those days  photosynthesis experiments  12 22 26 10 7 19 2 6 20 3 19 14 17  Note:  data  .8 .2 .0 .6 .8 .5 .8 .0 •Q .3 .0 .3 . 7  H20(2)  15 . 5 - 1 6 \4 . 0 - 1 6 14 . 5 - 1 5 15 . 2 - 1 7 14 . 0 - 1 6 14 . 4 - 1 7 12 . 0 - 1 2 12 . 6 - 1 2 12 . 0 - 1 3 10 . 1 - 1 0 9 .7-10 9 .6-10 9 .7-10  were  when  performed.  SUNRISE  SUNSET  CLOUDS  .0 .0 .8 .2 .8 .3 .5 .9 .0 .8 .0 .0 .0  0406 0406 0408 0417 0452 0509 0520 0534 0555 0 6 14 0639 0720 0725  2018 2022 2023 2018 1944 1923 1854 1846 1816 1 748 1716 1632 1629  0% 20% * 100% 10% 0% 0% 0% * 100% *100% 100% 0% 0% 208.  5 . 1 - 6 .. 5 8 . 1 - 8 . .6 9 . 4 - 1 0 .. 3 1 1. 0 - 1 2 . .9 12 . 1 - 1 2 . 9 13 . 2 - 1 5 . O 16 . 0 - 1 6 . 8 15 . 0 - 16 . 0 14 . 7 - 1 6 . 0 14 . 0 - 14 . 7 16 . 3 - 1 7 . 6 14 . 0 - 1 6 . 6 12 . 8 - 1 3 . 0  0803 0728 0637 0504 0455 0403 0351 034 1 0342 0354 0408 0437 0457  1641 1701 1747 1858 1904 1950 2004 2024 2024 2016 2004 1932 1908  0% *100% *100% 0% * 100% 0% 0% 50% *100% 100% 25% 0% *100%  day- 1 PFD  for  the day below  t h e mean d a i l y  PFD  for  the month  oo  Table  27.  Summary (1)  mg C  of  the diurnal  photosynthesis  g dry wt-1 d - 1 ; (3)  DATE  NET( 1 )  Ei HELBY 22  - ZONE  June  TOTAL(1) RESP  (2)  xlOE-07  experiments  f o r Fucus  mg C g d r y w t - 1  mg C g d r y w t - 1  uE-1  distichus m-2 d - 1 ;  h-1.  DAILY P/R  DIURNAL P/R  PSE(2)  MEAN(3) RESP  I  1982  7 . 68  2 .40  3 .2  5 .2  2 . 5  0.10±0.05  1982*  5.51  7 .68  0 . 7  2 .0  1.4  0.32±0.25  1982  7 . 85  2 . 40  3 .3  9 .1  7 . 5  0.10±0.05  17 N o v  1982*  7.95  1 . 20  6 .6  20 . 5  9 . 5  0.0510.02  15 J a n  1983  4 . 70  3 . 36  1. 4  6 . 2  9 . 1  0.1410.05  9 Feb  1983*  5.63  2 . 16  2 . 6  8 .. 8  18.0  0.0910.03  6 Mar  1983  7 .05  2 . 16  3 . 3  1 0 .. 1  5.8  0.0910.03  18 M a y  1983  9 . 28  2 . 40  3 ..9  7 .. 3  -  0.1010.03  29  June  1983  10.67  2 ..88  3 .7  6 .0  3 . 2  0.1210.04  13  July  1983*  10.85  3. 6 0  3 .0  5 .3  -  0.15+0.05  3 .84  2.5  5.1  2 . 5  0.16+0.07  19 A u g 3 Oct  12 A u g  1983*  9 .63  TABLE  27,  CONTINUED  DATE  HELBY  -  ZONE  NET( 1 ) PS  TOTAL( 1 ) RESP  DAILY P/R  DIURNAL P/R  PSE(2)  MEAN(3) RESP  I_I  22 dune  1982  11.45  4.08  2. 8  4.9  3.8  0.1710.08  19 Aug  1982*  14.16  3.84  '3 . 7  8. 3  3. 7  0. 1610. 10  2 Sep  1982*  10.20  4.32  2.4  5. 4  3.2  O. 1810.06  3 Oct  1982*  8.59  2.64  5.9  8. 2  8. 3  0. 1110.06  17 Nov  1982*  7.72  2.16'  3.6  11.3  9.2  0.0910.09  15 J a n  1983*  4.41  3.60  1. 2  5.6  8.6  0. 1510.07  9 Feb  1983*  6.32  1.44  4. 4  13.5  20.0  0.0610.02  6 Mar  1983*  8.45  3.36  2 . 5  6. 8  6.9  0.1410.07  20 A p r  1983*  8.41  3.84  2 . 2  4.8  5. 7  0.1610.05  18 May  1983  12.74  2.16  5.9  29 J u n e  1983*  13.71  3.36  4. 1  6.6  13 J u l y  1983*  11.43  5.04  2. 3  4. 2  12 Aug  1983*  10.46  3.84  2. 7  5.4  0.0910.04  10.2 4. 1  O.1410.05 0.21+0.05  2.7  0.1610.08  TABLE  27,  CONTINUED  DATE  NET( 1 ) PS  TOTAL(1) RESP  DAILY P/R  DIURNAL P/R  PSE(2)  MEAN(3) RESP  NUDIBRANCH 26 d u n e  1982*  10 d u l y  1982  8.20  5.04  1.6  3.3  3.6  0.21±0.12  11.06  9.36  1.2  2.6  2.9  0.39+0.23  1982*  8.39  4.32  1.9  4.0  2.1  0.1810.10  19 O c t  1982  6.99  3.60  1.9  6.0  4.2  0.1510.14  14 N o v  1982*  0.76  8.16  0.1  1.8  0.8  0.3710.14  16 A p r  1983*  12.87  5.28  2.4  5.2  3.7  0.2210.09  28 M a y  1983*  9.63  1.44  6.7  11.3  -  0.0610.05  27 d u n e  1983  11.52  3.60  3.2  5.0  -  0.1510.03  24  1983*  11.18  3.84  2.9  5.2  2.7  0.1610.03  1983*  7.06  3.'12  2.3  4.7  4.1  O.1310.05  7 Aug  duly  24 A u g  Note:  significant  diurnal  differences  in photosynthesis rates  (ANOVA)  Table  28.  A n a l y s i s of variance of  Fucus d i st i chus  of p h o t o s y n t h e s i s from  Zones  and  respiration  I and II o f Helby.  PHOTOSYNTHESIS  SOURCE  Month Zone Month*Zone Time o f Day Month*T i me Zone*T i me M*Z*T Res i dua1 Total  SUM OF  SQUARES  DF  MEAN  SQUARE  7.3003 1.0392 7.0632 9.0555 22 . 775 1.3848 15.867 133.64 198 . 17  12 • 1 •10 5 50 5 41 578 702  0.60836 1.0392 0.70632 1.8111 0.45551 0.. 27696 0..38700 0..23121  0.34992 4.8490E-03 0.14860 0.90323 1.4121  12 1 10 188 21 1  2.9160E-02 4.8490E-03 1.4860E-02 4.8044E-03  F-RATIO  6312 4944 0549 8332 9701 1979 6738  PROBABILITY  0.00197 0.03443 0.00087 0.00000 0.00014 0.30876 0.00635  * ns ** ** ** ns ns  RESPIRATION  Month Zone Month*Zone Res i d u a l Total  6.0695 1.0093 3.0930  0.00000 ** 0.31637 ns 0.00114 **  Diurnal for at  curves  of net  Fucus d i s t i c h u s Helby  A)  (mean  19 Aug  f r o m Zones I and I I  ± 1 standard  1982  deviation).  • = Zone I •  12 Aug  photosynthesis  = Zone I I  1983 A = Zone I A = Zone I I  B)  17 Nov  1982 o •  9 Feb  6 Mar  1983 ° •  29 J u n e  I  = Zone I I  1983 * = Z o n e I A  C)  = Zone  1983 A A  = Zone I I = Zone I = Zone I I = Zone I = Zone I I  Ci-l •  ^ P '  1  3  Sil  193  I  ©  195 While  significant  photosynthesis clearly  group  significant  the  Zone  on  18  were  based  May  common  plants. first  i n t h e Zone  analysis  were  (p<0.0l)  as  photosynthesis  between  found,  were  rates  differences  occasions:  22  always  June  1982,  f o r the Helby  analysis  (p<0.0l)  r e s p i r a t i o n was  1982.  Zone  greater  Analysis  of  1/18  1983  i n Zone I in  the  p<0.0l);  of  seasonal  in were  plants.  on  18 May  three  1983.  differences  were  also  in  observed  also significant.  d i d not c l e a r l y d i v i d e i n t h e Zone  the Month*Zone  II  observed and  by  highest  differences  i n t h e Zone  1982,  the  grouped  I I F\_ d i s t i c h u s  were  is  Zone  May  lowest  times  i n t e r a c t i o n was  greatest  This the  occasionally  d i st ichus  S-N-K  for  that  plants  rates.  analysis,  significant  I and  clear  I  , but r a r e  the  significant  28); t h e Month*Zone  August  also  the  in photosynthesis  usually  (S-N-K  19 A u g u s t  (Table  however,  were  of  were  t h e Zone  differences  in photosynthesis  Statistically respiration  Where Zone  (p<0.0l)  f o r t h e Zone  I I F\_ d i s t i c h u s  (#2-4)  rates.  and  not  only  photosynthesis  but not  t h e day  photosynthesic  Zonal  1982  of p h o t o s y n t h e s i s  incubations  The  in  did  result  photosynthesis  Diurnal  of  the  analysis  19 A u g u s t  plants,  incubation  S-N-K  t h e S-N-K  27).  is  (p<0.0l)  interaction.  of net d a i l y  1982  Rates  mid-day  on  differences  analysis  this  had h i g h e r  i n terms  (Table  S-N-K  months;  on  1983  August  plants  the  II p l a n t s  verified  found,  Month*Zone  distinctions  11/19  were  seasonal  t h e months;  I plants  interaction  on  19  using  196 the  respective  one-way  ANOVAs  differences  in respiration  Respiration  r a t e s were  both  daily  pattern  i n Zone  spring  and I  Zone  during P/R The  greatest  zonal  1983 a n d 21 J u l y  i n the  II  FV distichus  summer  (Table  II  Zone  diurnal  winter  showed  months  the e s p e c i a l l y Results  stepwise;  high  1983.  plants  MIDAS)  of  Table  in were  on  photosynthesis  of was  was  Multiple-R  coefficients  regression  equations  net/gross  none  the  quite  accounted  photosynthesis.  with  to  the only  for  were  of the  ,  water  both  high,  f o r 70-89%  II  zones; 1983.  (backwards, daily  factors are environmental net  daily  gross  daily  temperature.  significant  Zone  daily  greatest  gross  environmental  F^ distichus  also  equations  from  and  clear  fluctuations.  on 9 F e b r u a r y  net  strongly related  temperature  regression  recorded  the  recorded  ( P S E ) was  related  I  Zone  less  respiration,  distichus  While  in  were  and v a r i a b l e  abiotic  29.  was  values  daily  seasonal  rates  regression analyses  significantly  photosynthesis  The p a t t e r n  F^ d i s t i c h u s  presented  strong  highest  efficiency  in  of the m u l t i p l e  on s e l e c t e d  Water  wide  values  photosynthesis  factors  Total  of photosynthetic  the  , with  a  the largest  1983.  P/R  showed  27).  plants, although  measure  note  photosynthesis  spring/summer  and  during  the  on 6 M a r c h  significant  dates. Net  for  showed  factor in  plants.  indicating  The  that the  of the v a r i a n c e i n  Table  29.  R e s u l t s of m u l t i p l e r e g r e s s i o n analyses photosynthesis d i s t i chus from  ZONE  (mg C g d r y wt-1 Helby  on s e l e c t e d  net and g r o s s  day-1)  o f Zone  abiotic  environmental  daily  I and II Fucus factors.  1 FUCUS DISTICHUS  Net  Daily  Photosynthesis:  MULTIPLE-R NO  = 0.57362  VARIABLES  Gross  Daily  F=4.4135  IN REGRESSION  1,9df p=0.0650  ns  EQUATION  Photosynthesis:  GROSS PS = O.84(H20-T) + MULTIPLE-R  ZONE  of  3.74  = 0.83477  SE  =  1.3880  I I FUCUS DISTICHUS  Net  Daily  NET  Photosynthesis:  PS = O.84(H20-T) - 0.62 MULTIPLE-R  Gross  Daily  = 0.91421  SE  =  1.2194  SE  =  1.1745  Photosynthesis:  GROSS PS = 1.02(H20-T) + 0.69 MULITPLE-R  = 0.94179  U3  198 Daily  P/R  significantly  r a t i o s ' f o r Zone correlated  factors.  Diurnal  correlations  with  (r=0.80l6,  P/R  and  (PSE) of  correlated  with  exposure found  a  with  water  flux  density  air  (r=-0.8548,  the  Zone  I  temperature  of  p<0.0l),  plants  the  was  seawater  and  air  wave  correlations  per cent  gross  with  positively  p<0.0l)  (r=-0.8204,  and  positive  Photosynthetic  negative  p<0.0l),  environmental  correlation  (r=0.8796,  0.01<p<0.05);  were n o t  significant  0.01<p<0.05).  the  (r=-0.8231,  of  negative  rainfall  (r=0.7450,  any  concentration  (r=-0.7555,  efficiency  F\ d i s t i c h u s  showed  nitrate  p<0.0l)  temperature  with  I  p<0.0l),  time  daily  were  photon  exposed  to  photosynthesis  (r=-0.7794, 0.01<p<0.05). Diurnal positive  P/R  correlations  (r=0.69l4,  As  photosynthetic correlated.  with  with  water  in  the  and  gross  Zone  I I F. d i s t i c h u s  case  of  (r=-0.7798, .  nitrate  Zone  (r=0.7383,  I BV d i s t i c h u s was  negatively  and  a i r  0.01<p<0.05) d a i l y  flux  exposure  efficiency  n e t (r=-0.6459,  wave  correlated  0.01<p<0.05), p h o t o n  and  ,  positively  p<0.0l)  Photosynthetic with  showed  concentration  exposure  (r=0.8379,  0.01<p<0.05),  correlated  F^ di st ichus  i n Zone I I p l a n t s  (r=-0.7280,  0.01<p<0.05).  negatively  wave  0.0l<p<0.05) a n d  (r=-0.7243,  also  II  seawater  and  rainfall  temperature  (r=-0.7594,  Zone  with  efficiency  (r=0.7383,  density  in  0.0l<p<0.05)  0.01<p<0.05).  exposure  ratios  was  0.0l<p<0.05)  photosynthesis i n  199 Selected from  Zone  I  diurnal at  Significant  Nudibranch  seasonal  found  by a n a l y s i s  S-N-K  analysis  10 J u l y  photosynthesis  of v a r i a n c e  Apr  83  >  all  Photosynthesis diurnally  (F=36.592  Month*Time  occasions  (Table  parameters Table  for  27.  spring  Net  and  December  differed P=0.0001), divide  the  was  each  1982  to  daily  data.  June  83  >  F^ d i st ichus  also  (F=4.8853  noted  not  a  varied  significant 38,200df;  differences  observed  on  calculated experiment  in  only  three  photosynthesis are presented  in  was  greatest  in  however  are  no  f o r the  and  there 1983  diurnal  pattern.  S-N-K  83,27  photosynthesis  significantly but  were  follows:  and  The  March  seasonal  19.  p=0.0000).  p=0.0000)  diurnal  daily  as  diurnal  were  27).  summer,  respiration, consistent  rates  9,200df;  July  Nudibranch  Significant  photosynthetic  Figure  dates  5,200df;  interaction  p=0.0000).  other  82,24  in  photosynthesis  t h e months  19 O c t  in  in  (F=15.997  divided  f o r F^ d i st ichus  presented  differences  (p<.0l)  82,16  are  curves  period.  P/R,  and  Mean  diurnal  between analysis  PSE  months (p<0.0l)  data Total  the  daily  d i d n o t show respiration  (F=5.7459 did  not  any rate  9,64df; clearly  F i g u r e 19  Diurnal for  curves  Fucus  Nudibranch  of net  distichus  photosynthesis from  (mean ± 1 s t a n d a r d  •  = 10 J u l y  1982  •  = 19 Oct  1982  A  = 16 Apr  1982  A  =28  1982  May  Zone I a t deviation).  201  © O  00  rH-H r-°-H  i  I  o  \  «* H  GO  |-;'-H  h w •  ^  a  o  I—H oi.  —  i  —  i  ««  —  M i  —  (,-1  ,-»«**P*- 3  *• O  m  M  r  8  m  ) S J  o o  OP  o  202 Neither  the  daily  with  monitored.  Photosynthetic  correlated  with  temperature  of  diurnal  correlations  0.0l<p<0.05),  any  nor  air  and  ratio  abiotic  flux  temperature  significant  (PSE)  was  (r=-0.7686,  (r=-0.8761, and  (r=-0.7l93,  factors  negatively  density  0.01<p<0.05),  gross  had  environmental  efficiency  photon  (r=-0.7766,  P<0.01)  the  P/R  p<0.0l), net  water  (r=-0.8254,  0.01<p<0.05)  daily  photosynthesis. There  were  regression  (F=1.8537 a  The  PS  =  found  MULTIPLE-R  =  0.94593  correlation factors  air  are  (F=40.192 (F=8.9040  +  temperature  =  daily  factors 0.43373).  (F=17.009  3,6df;  9 . 0 6 ( A l R E 1 OP) SE  coefficients  were a l s o  gross  photosynthesis:  2.43(H20-T)  Selected sessile  daily  multiple  environmental  regression equation  f o r net  the  Multiple-R  -  water  to  abiotic  p=0.2105ns;  in  F\_ d i s t i c h u s  1.20(AIR-T)  environmental r = 0.79884;  variables  Nudibranch  selected  significant  partial  exposed  on  of  1,8df;  p = 0 . 0 0 2 4 ) was  NET  significant  analysis  photosynthesis  However,  no  quite  =  for  high:  r = -0.83949;  -  51.8  1.3690  the air per  significant temperature cent  time  r=0.85914. diurnal  presented I0,l06df;  4,l06df;  photosynthesis in Figure  curves  20a,b.  p=0.0000)  and  for  Hedophyllum  Significant diurnal  p=0.0000) i n p h o t o s y n t h e s i s  seasonal  differences were  found.  Diurnal  curves  of  net  photosynthesis  f o r Hedophyllum s e s s i l e from Zone I I I at Nudibranch  (mean ± 1 standard  June  1982  O  = 27 J u n e  1983  •  =  7 Aug  19 82  •  = 24 A u g  1983  =  Sep  1982  •  = 14 Nov  1982  A  = 16 A p r  1983  A  =  1983  A) •  B) •  = 26  20  28 May  deviation).  Table  30.  Summary o f (1)  the d i u r n a l  photosynthesis experiments  mg C g d r y w t - 1 d - 1 ;  (2) (3)  DATE  NET( 1 ) PS  TOTAL(1) RESP  X10E-07  for  Hedophy11 urn s e s s i 1 e  mg C g d r y w t - 1  u E - 1 m-2 d - 1 ;  mg C g d r y w t - 1 h - 1 .  PSE(2)  MEAN(3) RESP  DAILY P/R  DIURNAL P/R  4 . 56  3. 3  5 .0  6.6  0 . 19±0.23  26 J u n e  1982  24 J u l y  1982*  8 . 58  5 .04  1. 7  2 .9  2.0  0..21+0.09  7 Aug  1982*  5 .33  3 .60  1. 5  3 .9  1. 3  0 .15+0.07  20 Sep  1982  6 .08  2 . 16  2 .8  6.8  4. 5  0..09+0.05  19 O c t  1982  4 .02  2 .40  1. 7  5. 1  2.4  0..10+0.13  14 Nov  1982  1 .66  3 . 12  0 .5  2 .8  1 . 7.  0..13+0.06  16 A p r  1983  19 .68  2 . 16  9.. 1  15 . 8  5.7  0. 09+0.01  28 May  1983  10 .90  3 . 84  2 .8 .  4 .6 .  -  0 . 16+0.09  27 J u n e  1983  1 .113  5 .04  2 .2  3 .5  -  0. 21+0.13  24 J u l y  1983  9 . 10  3 . 12  2 .9 .  5,.0  -  0. 13+0.05  24 Aug  1983*  6 .08  3 . 12  1 .9 .  4 .4  4.6  0 . 13+0.07  Note:  15 .02  * significant diurnal  differences  in p h o t o s y n t h e s i s r a t e s  (ANOVA)  Table  31.  Multiple  regression  photosynthesis  Daily  of  (mg C g d r y wt-1  s e s s i1e on s e l e c t e d  Net  analyses  abiotic  net and g r o s s  daily  d a y - 1 ) i n H e d o p h y l 1 urn  environmental  factors.  Photosynthesis  NET  PS = 1 . 5 6 ( A I R - T ) - 3.78(H20-T) - 2 . 8 8 ( S A L I N I T Y ) + 2 . 4 3 ( A I R E X P ) + 71.34  MULTIPLE-R  Partial  Correlation  Air  = 0.93623  SE  Coefficients:  0.65953  Temperature  Water  Temperature  Sa1i n i t y Air  Gross D a i l y  = 2.3470  Exposure  p=0.0752ns  -0.76834  p=0.0259*  -0.88315  p=0.0036**  0.88639  p=0.0034**  Photosynthesis  GROSS PS = 1 . 9 2 ( A I R - T ) - 1 . 7 1 ( S A L I N I T Y ) + 23.79  MULTIPLE-R  Partial  Correlation  Air  = 3.0863  Coefficients:  Temperarture  Sa1i n i t y  SE  = 0.86050  r  =  0.73407  r  = -0.79533  p=0.0156* p=0.0059**  K3 O  208 A  significant  (F=3.4603  Month*Time  36,106df;  photosynthetic 1982  and  showed  that and  other  months.  26  1983  June  daily  seasonal  pattern  with  30).  and  d i d n o t show  were  Total  not  ratios  and PSE  30).  Daily  (r=0.8880,  were P/R  Mean  sessile  abiotic The  variance  and  environmental  equations  P/R  rates  a  strong  and  summer  note  P/R  pattern  and  any  of  the  that  the  16 A p r i l  1983  P/R  (Table  with  net  0.0l<p<0.05)  daily  correlated significantly (r=0.7908, did  multiple  not  0.01<p<0.05). vary  gross  regression  daily  seasonally  factors  are  f o r 74%  (gross)  i n the photosynthesis  analysis  photosynthesis presented  c o e f f i c i e n t s are quite  account  April  between the  correlated  was  (p<0.0l)  p=0.24403ns). the  net  with  (r=0.8l60,  photosynthesis  respiration  of  Multiple-R  gross  but d i u r n a l  I0,54df;  Results  positively  and  net d a i l y  (F=l.3194  H.  was  on  August  and d i u r n a l  seasonal  However,  in  10  showed  daily  correlated  monitored.  on  difference  consistent  noted  7  analysis  i n the spring  r e l a t i v e l y large  p<0.0l)  diurnal  little  rates  and  greatest  respiration,  any  factors  photosynthesis, with  daily  24 J u l y  S-N-K  were  also  differences  i n H_;_ s e s s i l e  highest  significantly  environmental  only  rates  photosynthesis  on  30).  with  was  diurnal  observed  (Table  1983,  (Table PSE  were  photosynthetic  1983  Net  p=0.0000);  rates  24 A u g u s t  interaction  and  in  large; 88%  parameters.  the  on  of  selected  Table  31.  regression  (net) Opposing  of  the  effects  T a b l e  32.  In  TIME  s i t u  b l a d e  g r o w t h  INTERVAL  in  Hedophv11um  BLADE  s e s s  i1e  GROWTHQ)  1982  27 . 7  ±  2 .. 7  8 .9  ±  3 .. 0  7 . 8  +  1 .. 9  1 1 .9  ±  3 :. 0  JUL  1 0 .. 7  +  O .. 8  AUG  8 ,. 2  ±  6 . 2  25  AUG  -  8  SEP  8  SEP  -  22  SEP  30  APR  -  20  MAY  20  MAY  -  12  JUN  12  JUN  -  17  17  JUL  -  9  1983  1 .00  TOTAL(2)  Note:  (1)  mg  (2)  g  C C  b l a d e " b l a d e  -  1  1  d~ ' o v e r  t h e  s t u d y  p e r i o d  ho to  are  shown  by  water  and  factors  being  positively  Chapter  2).  However,  photosynthesis spring, not  and  between  September an  true  error  growth 1982  the  ratios;  the  wet  differed  from  data  were the  data  H_^  on  observations (i.  e.  two  Chapter per  plant,  the  rn  If  the  situ  annual The  and  rates  are were  (Figure  daily  given  and  the  probably  environment.  weight:surface  and  area  this  S-N-K  each also net  were  25  x  25  assumes  was  species  are  in  the  Cladophora  33.  of  was  time  the  did  not  g  C  were  six  sessi le  32  nr  2  see  blades during  irr . 2  curves  presented  ca  sampled;  H_;_  for  in Figures  parameters largest  chlorophytes spp.  time  qualitative  there  The  area  obtained,  that  photosynthesis  to  quantitative  quadrat  photosynthesis  due  22  no  cm  192.1  to  this  (p<0.01)  density  productivity  8  been  first  Although  plant  from  have  the  analysis  intervals.  that  greatest  regression at  was  do  relationships  wet  of  no  early  may  in Table  observed  27)  and  the  and  this  experiment  secondary  winter  however  diurnal  calculated  plants  total  growth  Selected  sessile  densities  one  the  (see are  32),  suggest  3).  for  there  was  time  p l a n t s per  that  two  other  sessile  others,  sessile  noted  of  weight:surface  other  each  these  H_;_  collected.  separate  with  view  calculation  the  despite  regression equations  i n H_;_  in  (Table  in  the  year-round  photosynthesis  Blade  be  f o r IU_ s e s s i l e  data  a  correlated i t should  therefore  represent  a i r temperature,  21-27. these  photosynthetic  Ulva  ( F i g u r e 21)  for  various  and  fenestrata the  lowest  rates 22)  in  the  and  rhodophytes  Halosaccion  photosynthetic F.  distichus  woodi i  and  (Figure  Neorhodomela and  total  but  were  lack to  of  also  observed from  factors:  in  these  limiting  to  differences  algae,  September  and  (2)  Cryptosiphonia  (Figure  daily  light  greater  other on  this  were plant  and  7 August  S-N-K 1982  fact did  lack  monthly analysis experiment  in  rates  were  larix  ,  (except This  is  due  photosynthetic  have  most  of  early  morning  might  in  the  have  significant  observed  been diurnal  surprising, the  PS  vs  I  A).  vancouveriensis  differences (p<0.0l) as  those  1982).  L_j_ d i f f o r m i s i s  Appendix  in Corallina  of  N_;_  rates  that  not  intensities  apparently (see  in  species  variance  the  by  and  in photosynthesis  the  The  25)  photosynthesis  amer i c a n u m  species  in  ).  ,  large  in photosynthesis  significant  p=0.0000).  the  photosynthesis.  Photosynthesis showed  spp.  in  Intermediate  photosynthetic  Nudibranch  these  where  differences for  1)  with  incubations,  curves  higher  diurnal differences  spp.  experiments  as  were  vancouveriensis  in  difformis  (Figure  observed  d i u r n a l diffe-rences in photosynthesic  two  rates  noted  respiration  never  Cladophora  ) were  Cladophora  24).  those  Net  the  Significant C^  to  26).  with  in  (similar  (Figure  f e n s t r a t a and  found  (Figure  Leathesia  larix  vancouveriensis  americanum  sessile  23),  daily  species (  rates  Corallina  the  (Figure  (F=10.567  4,75df;  d i s t i n g u i s h e d the time  of  22)  20  lowest  212  Figure  D i u r n a l curves of net  21  photosynthesis  f o r Cladophora  spp.  (mean ± 1 s t a n d a r d d e v i a t i o n ) .  •  =  2 Sep  1982  •  =  3 Oct  1982  A  =  24  July  1983  0600  1000 1400 Time(PST)  1800  214  Figure  D i u r n a l curves of net  22  photosynthesis  for C o r a l l i n a vancouveriensis. (mean ± 1 standard  deviation).  •  =  7 Aug  1982  •  = 20 Sep  1982  A  =18  1983  Apr  215  ( _q . f  iCap 3 . o 3m ) Sd.  216  Figure  D i u r n a l curve of net  23  photosynthesis  for Cryptosiphonia (mean ± 1 s t a n d a r d  woodii  deviation).  —I  0600  1  1 1 1 1000 1400 Time ( P S T )  1  1—  1800  218  Figure  24  D i u r n a l curves of net for Halosaccion  photosynthesis americanum  (mean ± 1 standard  deviation).  •  = 26 June  1982  •  = 19 Oct  1982  219  D i u r n a l curves of net p h o t o s y n t h e s i s for Leathesia difformis (mean ± 1 s t a n d a r d  deviation).  •  = 12 June  1982  •  = 29 June  1983  A  = 13 J u l y  19E3  — i 0600  1  1  1  r  1000 1400 Time(PST)  1  1— 1800 ho ho M  222  F i g u r e 26  D i u r n a l curves of net p h o t o s y n t h e s i s f o r Neorhodomela l a r i x (mean ± 1 standard  •=  .  deviation).  10 J u l y  1982  26 May  1983  27 June  1983  7IZ— 0600  1  1  1  •  1000 1400 Time(PST)  1  r-  1800  Figure  27  D i u r n a l curves of net for Ulva  photosynthesis  fenestrata  (mean ± 1 s t a n d a r d d e v i a t i o n ) .  •  =  2 Sep  1982  •  = 18 May  1983  A  = 24 Aug  1983  8.0-1  9.74 Ulva  6.0 -  6  a  w 00  8.0  1 1  -~Z--i T  0600  r  I  1  1  lOOO 1400 Time(PST)  i  r  1800 tS3  Table  33.  Summary o f d i u r n a l  photosynthesis  experiments f o r s e l e c t e d  intertidal  macroalgae.  ( 1 ) mg C g d r y wt-1 d-1; ( 2 ) x l O E - 0 7 mg C g d r y wt-1 uE-1 m-2 d-1; ( 3 ) mg C g d r y wt-1 h-1.  SPECIES/DATE  DAILY P/R  DIURNAL P/R  PSE(2)  MEAN(3) RESP  NET( 1 ) PS  TOTAL(1) RESP  7 .57  3.12  2. 4  4.4  3.3  O. 13+0.10  5 . 55  3.84  1 .4  3.4  1 .4  0.16±0.17  1982  6 .89  0. 48  14 . 4  29.0  2 -.4  0.02±0.01  20 Sep  1982*  4 . 38  0. 72  6 . 1  13.3  3.3  0.03±0.01  16 A p r  1983*  5.87  4 . 32  1. 4  3. 3  1. 7  5.04  2.7  7.0  9.2  C. V a n c o u v e r i e n s i s 26 J u n e  1982  . 7 Aug 6 Sep  1982*  0.18  C. woodi i 20 A p r  1983  13.68  0.21+0.08  TABLE  33,  CONTINUED  SPECIES/DATE  Cladophora  spp.  NET( 1 ) PS  TOTAL(1 RESP  DAILY P/R  DIURNAL P/R  PSE(2)  MEAN(3) RESP  Helby  2 Sep  1982  3 3 . 54  1 1 .28  3.0  6.8  11.0  0 . 4 7 ± 0 . 19  3 Oct  1982  12.47  3.12  4.0  9.7  12.0  O.13+0.07  C1adophora  spp.  Nudibranch  7 Aug  1982*  31 . 7 9  9 . 12  3.6  7.0  7.9  0.38±0.31  6 Sep  1982  40.26  8.40  4.8  9.7  34.0  0.35±0.25  20  Sep  1982  2 7 . 74  6.00  4.6  9.9  21.0  0.25±0.10  24  July  1982  35 . 84  9 . 36  3.8  6.5  8.0  0.39±0.19  H. 26  amer i canum June  1982*  7 .46  2.40  3.1  6.0  3.3  0.10+0.07  20 Sep  1982*  7 . 30  1 .68  4.3  9.7  8.5  0.0710.03  19 O c t  1982*  3.87  2 .88  1.3  4.2  2.3  0.1210.12  24  1983*  6 . 27  4.80  1.3  2.7  1.5  0 . 2 0 + 0 . 12  July  TABLE  33,  CONTINUED  SPECIES/DATE  L.  PSE(2)  NET( 1 ) PS  TOTAL(1) RESP  8 . 73  5.04  1. 7  3 . 3  2.0 5.9  DAILY P/R  DIURNAL P/R  MEAN(3) RESP  di fformis 0.21±0.18  22 dune  1982  29 J u n e  1983  19.62  3.12  6 . 3  8 .7  13 J u l y  1983  25.02  15 . 60  1. 6  3.6  12 J u n e  1982*  14 . 25  4 . 32  3 . 3  5 . 4  3 . 9  0.18±0.11  10 J u l y  1982*  12.00  0.9  1 .9  3 . 1  0.58±0.35  6 Sep  1982  16,72  5 . 76  2 . 9  6 . 7  14 . 0  0.24±0.09  28 May  1983*  17.85  2.88  6 . 2  27 J u n e  1983  18 . 98  •8.16  2 . 3  4 . 1  N.  0.13 0.65+0.26  1ar i x  U.  13.92  4 .4  0.34±0.08  fenestrata  2 Sep  1982  48.58  19.68  2.5  5 . 5  18 May  1983  22 . 19  10. 56  2 . 1  3.8  24 Aug  1983  52 . 70  12.96  4 . 1  8 . 3  Note:  0.12+0.02  10.5  *  significant  diurnal  differences  in p h o t o s y n t h e s i s  rates  15.0  0.82±0.17 0.44±0.18  40.0  0.54±0.09  (ANOVA)  00  photosynthetic daily  photosynthesis  performed, C.  rates;  i t  diurnal (Table  P/R  p=0.0000).  the  spp.  i n September  other  also  ANOVA  respiration  reduced  (Figure  greatest  of net  was rates  not in  1982,  with  Daily  and  i n September  1982  months.  rates  were  with  the other There  ratios,  Photosynthesis  4,56df;  differ  p=0.0000); other  The  seasonal  monthly  (Figure  two  dates rates  )  was  showed  P/R  greatest  a  (Figure  24)  (F=4.6793  parameters d i d  (Table  33). difformis  (F=32.364 on  (S-N-K  1983  the  diurnally  pattern  29 J u n e  in  (F=2.7521  but p h o t o s y n t h e t i c on  S-N-K  months  noted  greatest  d i d not d i f f e r  rates,  were  were  by  33).  photosynthesis patterns  1982 f o r  greatest  americanum  vary  5,86df;  differences in  differences in Leathesis  25  photosynthesis  few  between  did  other  3 October  not segregated  (Table  significantly but  on  was  plants  photosynthesis  Respiration  ratios  PSE  significantly  (F=10.488  apparently  in Halosaccion  any a p p a r e n t  photosynthesis  were  1982  p=0.00250).  Significant  observed months  but  p=0.05103ns),  show  showed  Lowest  P/R  3,56df;  also  of photosynthesis  (p<0.0l).  not  21)  rates  Nudibranch/September  the  that  i n terms  an  monthly  plants,  analysis  not  Although  the  were  verified  33).  different  did  much  between  ratios  Cladophora  Helby  33).  appear  were  difference  i s also  (Table  would  Vancouveriensis  little  this  13 J u l y  2,37df; 1983, b u t  analysis,  p<0.0l).  similar  to  efficiency (Table  33).  the  and the  230 Photosynthesis monthly  (F=10.046  (P<0.01)  did  differences 1982  and  were  not  May  1983  September  p=0.0000)  in with  three  on  the  terms  and  (4.38-7.57)  H.  1982  (1.66)  net  analysis  months.  Diurnal  i n the  diurnal  PSE  N.  was  summer  P/R  ratios  greatest  in  the  diurnal  C  fixed i n U^  were  and  observed  americanum  plants, 12.87  , net  daily  and  highest  g  were  4.41  and  dry  Fairly L^  wt"  in April  1983  and  day" ,  1  1  (22.19-52.70) rates  d i f formi s  were (8.73-  net  daily  vancouveriensis  between  was  1982  33).  Lowest  14.16  for  differed.  high  i n C^  1983  similar  (Table  Net 4.70  daily  and  10.85  in Helby/Zone  in Nudibranch/Zone  photosynthesis  May  September  (3.87-7.46). ranged  18  ratios  days  (13.68),  rates  I  2  on  fenestrata  (12.00-18.98).  distichus  2,35df;  P/R  on  experimental  C_;_ w o o d i i  i n F\  (F=41.733  ratios  (12.47-40.26).  H.  monthly  recorded  P/R  greatest  mg  significant  rates  larix  and  0.76  showed  values  greatest  for  Helby/Zone  sessile  two  spp.  photosynthesis  and  27)  Daily  were  was  recorded  plants,  varied  S-N-K  found  and  while  (Figure  although  of  photosynthesis  in  were  Daily  lowest  other  Cladophora  25.02)  rates  1983  p<0.0l).  rates  photosynthesis  also  May  the  months,  Respiration  and  segregate  photosynthetic  analysis,  In  the  fenestrata  differences  similar  clearly  26)  1982.  Ulva  all  (Figure  but  experiments. in  larix  4,70df;p=0.0000 ) ,  in photosynthetic  greatest  (S-N-K  i n Neorhodomela  I  lowest  (19.68).  plants. in  II In  November  231 The  net  conjunction 3)  daily  with  estimates  to calculate  interval; of  these  annual  period.  values  were  over  of these  i n Tables  34 t o 3 7 .  herbivory,  the  value  wave a c t i o n ,  calculated  annual  the  standing  reduced  compared  with  were  standing  crop  each  summed the  June  I t should  of  the  LOS  net p r o d u c t i v i t y . crops  summer  observed 1982.  values  calculated  were  and/or  losses  This  less,  than  1983  site are that,  (losses  in  due t o  exceeded  the  i s the result the  also  f o r June  sampling estimate  be n o t e d  during  This  an  f o r each  period  in  (Chapter  1982 t o J u n e  term  etc.)for this  used  six-week  to give  calculations  productivity higher,  rates  between  then  The r e s u l t s  cases,  1983  of a l g a l  productivity  productivity  presented most  photosynthesis  spring/summer  suggests  1982  of  to  that  June  the 1983  f o r t h e same p e r i o d  in  1981-1982. Annual  productivity  populations  i n Zones  740  year" ).  g C m~  2  g C nr  year  populations  - 1  )  productivity nr  2  year" ) 1  Wizard  2  of  much  (275 g C n r  the  productivity  the  three  this greater  with 2  Helby  year" ); 1  o f t h e Zone  sheltered  was  lower  sites.  sites  I  (55.8 g C  plant.  Fucus  i n Zone  I at Haines  (220 g  C  there  was  m"  nr  2  distichus (740 g C  year" )  2  1  little  II F^ d i s t i c h u s  (220-  i n t h e Zone I I I  and Nudibranch/Zone  1  compared  i n t h e F\_ d i s t i c h u s  I and II of the s h e l t e r e d  year" )  was  greatest  Productivity  1  (72-192  was  difference  populations  and in at  Table  34.  Daily  and annual  net p r o d u c t i v i t y  JUNE AUG SEPT J J ) T J ) J J AUG SEPT NOV  ZONE  )  for  NOV J J 3 JAN  selected  JAN J J ] MAR  intertidal  MAR T 0 J APR  macroalgae at  APR MAY J 3 T 0 MAY JUNE  Haines  TOTAL ( 2 )  JUNE TO AUG  I  F . d i st i chus LOS( 1 ) NET PRODUCTIVITY(1) P/B R A T I O  2 . 6 3 - 0 .. 9 2 1 . 13 1 .. 2 6 0 .. 16 0 . . 2 3  3 . 10 3 .08 0 . 38  5 .. 17 - 1 . 13 3 . 39 1 .. 1 1 2 . 3 5 3 .. 0 2 0 .. 5 9 0 .. 2 7 0 , .31  3 . 69 2 . 70 0 .. 4 9  0 .. 3 5 1 .. 14 0 .. 2 2  788 . 3 740.0 2 . 65  2 .50 1 .31 0 . 23  4 . 27 4 . 08 0 . 68  3 . 23 3 . 83 0. 70  7 .. 27 2 . 75 0 . 42  0. 80 0 . 72 0 . 56  0. 79 0. 44 0 . 27  0. 95 1 .61 0 . 54  2 . 31 2 . 91 0 . 71  836 . 3 736 . 9 4 . 26  3. 1 1 2 . 77 0 . 62  F. d i s t i c h u s LOS NET PRODUCTIVITY P/B R A T I O  2 .08 - 0 . . 2 9 0 .. 6 3 O,. 19 0 ..36 0 ..68  0 . 20 0 . 35 0.42  NA NA NA  NA NA NA  -0.15 0.04 0 . 53  0.06 0 . 22 0 . 73  100. 2 72 .0 3 . 72  0 .53 0 .27 0 .62  L. d i f f o r m i s LOS NET PRODUCTIVITY P/B R A T I O  0 . .52 0 . 18 0. 43  .004 .001 0.43  NA NA NA  NA NA NA  - . 0 0 2 - . 0 0 8 - 0 . 23 .017 .0003 .003 1 .47 1 . 24 1 .00  38 . 5 10. 3 5 .04  0 .. 5 0 0 .. 4 3 1 ..7 5  ZONE  II  F. d i s t i c h u s LOS NET PRODUCTIVITY P/B R A T I O  ZONE  -1 . 3 6 0. 60 0 . 38  III  0. 1 1 0. 04 0 . 47  NA NA NA  ho CO hO  TABLE  34,  CONTINUED  JUNE TO AUG  ZONE  AUG TO SEPT  SEPT TO NOV  NOV TO JAN  JAN TO MAR  MAR TO APR  APR TO MAY  MAY TO JUNE  TOTAL(2 )  JUNE TO AUG  III  C. v a n c o u v e r i e n s i s LOS NET P R O D U C T I V I T Y P/B R A T I O  .034 .01 1 0. 29  . 0 1 4 •- . 0 1 1 .004 .0005 0.31 0. 20  NA NA NA  NA NA NA  - . 0 0 2 - . 0 0 8 - 0 . 23 .0066 .038 .005 0 . 26 0. 30 0.23  8.9 2.9 1 . 59  .002 .001 0. 25  N . 1ar i x LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 33 0 . 22 0 . 33  0.22 0 . 19 0.43  0.45 0 . 18 0.41  NA NA NA  NA NA NA  -0.15 .01 1 0.42  0.15 .079 0.21  34 . 0 30. 7 2 . 25  .077 0.17 0. 50  Cladophora spp. LOS NET P R O D U C T I V I T Y P/B R A T I O  - .005 .041 2.80  0.24 0 . 19 3.28  .004 .003 0.67  NA NA NA  NA NA NA  - .005 .002 0.94  0.17 0 . 19 4 . 20  0 . 26 0.23 3 . 35  27 . 1 28.5 15.2  0 . 10 0 . 14 3.67  H. a m e r i c a n u m LOS NET P R O D U C T I V I T Y P/B R A T I O  - .002 .051 0 . 37  0.11 .069 0.12  0.15 .036 0 . 24  NA NA NA  NA NA NA  - .038 - 0 . 0 4 .0008 .012 0 . 33 0.30  0.08 .029 0 . 29  10.6 8 . 43 1 .65  .015 .015 0.31  T O T A L LOS T O T A L NET  Note:  219.6 252.8  PRODUCTIVITY  ( 1 ) mg C m d" ( 2 ) g C m-* y ' (June NA = n o t a v a l i a b l e !  -0.22 .041 0.45  1  1982  -  June  1983)  Table  35  Daily  and annual  net p r o d u c t i v i t y  for selected  JUNE TO AUG  AUG TO SEPT  SEPT TO NOV  NOV TO JAN  0 .83 0 .80 0 . 16  3 . 15 0 .95 0 . 20  2 . 36 1 .0 4 0. 4 1  0 . 69 0 . 47 0. 65  F. d i s t i c h u s LOS NET P R O D U C T I V I T Y P/B R A T I O  4 .69 4 . 13 o .67  4 .92 3 .86 0 . 74  3 . 96 1 .9 3 0. 45  0 . 85 0 . 83 0 . 62  Cladophora spp. LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 12 0 . 16 2 .80  0 . 24 0 . 30 3 . 39  0 . 22 0. 1 1 0 . 73  .057 .034 2 . 52  ZONE  macroalgae  at  Helby.  TOTAL(2)  JUNE TO AUG  APR TO MAY  MAY TO JUNE  - 0 . 1 4 - 0 . .07 0.21 0 . .41 0. 22 0 .. 34  0 . 25 0.45 0 . 28  1 .04 0 . 44 0 . 23  377 .9 220. 4 2 . 49  -1 . 6 8 0.31 0 . 26  1 . 5 7 - 0 . 74 0.60 0. 60 0 . 24 b. 43  0.59 1 .40 0.53  3 .21 2 . 67 0 . 74  844 . 9 715.2 4 . 40  1.41 1 .84 0.63  23.4 27.9 13.95  0.52 0.54 3.43  JAN TO MAR  MAR TO APR  I  F. d i s t i c h u s L0S( 1 ) NET P R 0 D U C T I V I T Y ( 1 ) P/B R A T I O  ZONE  intertidal  II  TOTAL LOS T O T A L NET  PRODUCTIVITY  0 0 -  0 0 -  0 0 -  - 0 . 15 .008 4 .51  868 . 3 733 . 1  N3 Co  Table  35,  CONTINUED  JUNE 12 AUG  AUG 12 SEPT  SEPT 12 NOV  NOV 12 JAN  F . di st ichus LOS NET P R O D U C T I V I T Y P/B R A T I O  1 .63 1,. 3 3 0 .67  1 ..9 9 1 .. 17 0 ., 74  0. 88 0 . 35 0. 45  NA NA NA  L. d i f f o r m i s LOS NET P R O D U C T I V I T Y P/B R A T I O  0 .. 2 8 0 ., 0 9 0 . 44  .008 .003 0.47  U. f e n e s t r a t a LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 13 0 . 14 6 . 69  0 .. 2 0 0 .. 24 7 . 90  C. w o o d i i LOS NET P R O D U C T I V I T Y P/B R A T I O  .044 0.02 0 . 78  0 0 -  C1adophora spp. LOS NET P R O D U C T I V I T Y P/B R A T I O  .032 .025 2.80  - .027 0.21 3.40  ZONE  MAR 12 APR  APR 12 MAY  MAY 12 JUNE  TOTAL  JUNE TO AUG  0. 1 1 0 . 35 0 . 74  220.7 152.3 3 . 13  0 . 19 0 . 44 0. 63  10 . 4 2 39 . 95 3 . 56  0 . 35 0, 23 1 .8 8  III  T O T A L LOS T O T A L NET Note:  JAN 12 MAR  0 0 -  0 .. 5 6 0 ..51 7 .. 4 8  0 0 -  0 .. 38 0 . 22 0 . 73  NA NA NA  •  1  NA NA NA  0 0  -  0 ..44 0 . 31 0. 53  - . 0 3 6 - .031 .003 .055 1 . 37 1 . 28  NA NA NA  - .035 .004 1 . 54  .049 .065 1 . 65  0 . 10 .089 1 . 54  44 .0 45.87 26 . 8 0  0 . 29 0 .. 2 7 6 . 50  NA NA NA  NA NA NA  - .085 .002 0 . 78  .099 0.07 0.83  .055 .045 0 . 78  4 .94 5 .. 8 9 3.. 17  , • .086 .039 0.83  NA NA NA  NA NA NA  - .002 .008 3.51  0. 55 .049 4 .02  0 . 19 0 . 18 3 . 51  4 8 .. 9 4 7 2 .. 3 8 17 . 9 7  .044 0 . 14 3.84  "  2  NA NA NA  NA NA NA  329.0 316.4  PRODUCTIVITY  (1) g C md(2) g C m" y - ' (June NA = n o t a v a i l a b l e  NA NA NA  1  1982  to June  1983  )  ^ i_n  Table  36  Daily  and annual  net p r o d u c t i v i t y  for selected  JUNE TO AUG  AUG TO SEPT  SEPT TO NOV  NOV TO JAN  2 . 28 1 .02 0 . 16  3 . 26 0 .. 9 0 0 . 19  1 .47 0 ..96 0 .. 4 0  1 .06 0 .. 7 5 0 . 57  0. 44 0. 37 0 . 32  F . di st ichus LOS NET P R O D U C T I V I T Y P/B R A T I O  3 . 1 1 3 .95 3 . 43 3 .95 0 . 75 0 ..64  3.49 1 .68 0 . 45  Cladophora spp. LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 25 0 . 21 2 . 80  .037 .094 3 .40  .045 .063 0.71  SPECIES  ZONE  TOTAL TOTAL  MAR TO APR  macroalgae  at  Wizard.  APR TO MAY  MAY TO JUNE  TOTAL(2 )  JUNE TO AUG  0 .. 6 0 0 .. 8 6 0 .. 4 0  0. 63 0. 62 0 . 24  425 . 1 275.3 2 . 59  .069 0 . 66 O. 2 5  0.75 0.73 0 . 54  1 . 32 - 1 . 44 .056 0.49 0 . 36 1 . 26 0 . 33 0 . 38 0 . 56  3 ..51 2 .. 8 6 0 .. 7 6  734 . 7 660.9 4.41  1 .43 1 .99 0.63  0 . 16 .086 1.14  .008 .005 0.89  - .004 .026 4 . 39  0 . 12 0 . 14 3 . 67  25.6 28 . 7 17.6  .017 0 . 22 3.51  I  di st ichus LOS( 1 ) NET P R O D U C T I V I T Y ( 1 ) P/B R A T I O  ZONE  JAN TO MAR  intertidal  - 0 .. 64 0 ,. 4 7 0 . 31  II  LOS NET P R O D U C T I V I T Y  .001 .003 0.61  760. 689 .  ON  TABLE  36,  CONTINUED  SPECIES  JUNE I ° AUG  AUG SEPT I O I O J SEPT NOV  F. d i S t i c h u s LOS NET P R O D U C T I V I T Y P/B R A T I O  0 ., 5 2 1 ..0 2 0 .. 6 6  2 .48 1 .41 . 0 .. 7 5  L. d i f f o r m i s LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 37 0 . 12 0 . 44  .037 .012 0 . 48  0 0  o0  0 0  U. f e n e s t r a t a LOS NET P R O D U C T I V I T Y P/B R A T I O  0 . 25 0.31 6.69  0 . 76 0 .83 7 . 89  1 .45 1 . 30 7 .08  NA NA NA  N. larix LOS NET P R O D U C T I V I T Y P/B R A T I O  - .098 .045 0. 30  .06 0. 27 0. 98  0 .. 3 0 0 , . 27 0. 43  NA NA NA  ZONE  T  JAN MAR O T O T MAR APR  APR O T MAY  MAY O JUNE  NA NA NA  1 ., 1 1 0 .. 2 7 0 . 73 0. 80 0. 55 0 . 76  TOTAL ( 2 )  JUNE TO AUG  233 . 3 191.8 3.17  .017 1 .01 0.63  0 ,. 4 3 0 .. 3 1 1 .8 7  III  TOTAL.LOS T O T A L NET  Note:  NOV J ) JAN  0 .,84 0. 39 0 . 45  -  -  NA NA NA  - .08 .007 1.51  .038 .099 0.98  15.1 10.3 4.52  NA NA NA  - .018 .038 .0035 .036 1 . 32 1 . 84  0.01 .029 1 .60  108.6 109 . 3 26 . 4  0 . 27 0 .. 3.1 8 . 14  NA NA NA  - . 0 2 8 - . 13 .001 .032 0 . 4 0 1 . 27  0.04 .087 0.48  2 8 .6 30.9 3 . 86  0 .. 3 3 0 . 49 0 . 49  -  -.0008 .0029 1.11  385.6 342.3  PRODUCTIVITY  (1) g C md"' ( 2 ) g C m-* y - ' ( J u n e NA = n o t a v a l a i l a b l e  NA NA NA  !  1982-June  1983)  N3 Co  Table  37  Daily  and annual  JUNE TO AUG  SPECIES  ZONE  LOS( 1 ) NET PRODUCTIVITY( 1 ) P/B RATIO  LOS NET P/B  I.  LOS NET P/B  AUG TO SEPT  for selected  SEPT TO NOV  NOV TO JAN  JAN TO MAR  0. 55 0. 23 0. 33  NA ' NA NA  NA NA NA  intertidal  APR TO MAY  MAR TO APR  macroalgae  MAY TO JUNE  at  TOTAL(2)  Nudibranch  JUNE TO AUG  I  F . d i st i chus  P.  net p r o d u c t i v i t y  1imi t a t a  (used  F.  0. 25 1.17 0.31 0. 38 0.23 0. 28 d i s t i c h u s; d a i l y  PRODUCTIVITY RATIO  cornucopiae  ( u s e d U.  PRODUCTIVITY RATIO  TOTAL LOS TOTAL NET PRODUCTIVITY  photosynthesis  - .034 .056 .053 .008 .021 .014 0. 23 0. 27 0. 33 fenestrata  0. 25 0. 22 0.21 0.15 1 . 77 1.91  d a i l y  .036 0.03 1.71  NA NA NA  data  NA NA NA  photosynthesis  NA NA NA  NA NA NA  NA NA NA  .091 0. 35 0. 24 0.15 0. 36 0. 25  103 . 1 55 . 8 1 . 45  0. 33 0.11 0. 28  )  NA NA NA  .094 .094 0.61  .037 .037 0. 59  14.2 7.5 6 . 59  .045 .013 1 .92  data  0.5) - .03 .039 .007 0.03 0.61 0. 59  22 .0 18.2 6 . 59  0. 10 .075 1 . 92  NA NA NA  X  139. 3 81.5  W  00  TABLE 37,  CONTINUED  SPECIES  JUNE TO AUG  AUG TO SEPT  SEPT TO AUG  NIV TO AUG  JAN TO AUG  MAR TO AUG  APR TO AUG  MAY TO AUG  0 . 26 0 .86 0 . 33 0 .83 6 .69 7 .48  0 .62 6 . 55 6 . 33  NA NA NA  NA NA NA  NA NA NA  0 0  0 0  -  -  0 . 55 0 .58 0.. 37 0 .39 0..66 1 .09  0 . 33 0 . 18 0..98  NA NA NA  NA NA NA  NA NA NA  - . 18 .022 1.15  TOTAL  JUNE TO AUG  ZONE I I U. f e n e s t r a t a LOS NET PRODUCTIVITY P/B RATIO N.  0.28 0. 34 9.16  0.13 0. 26 1.15  59.9 51.9 5 .03  0.76 0.44 1.31  18 . 3 10. 1 1 . 30  0.41 .038 0. 29  larix  LOS NET PRODUCTIVITY P/B RATIO C.  74 . 2 72.9 20. 5  Vancouveriensis  LOS NET PRODUCTIVITY P/B RATIO  0. 29 0. 07 0. 25  46 . 0. 65 .015 0. 1 1 0. 28 . o.20  NA NA NA  NA NA NA  NA NA NA  - .014 .018 0. 29  .007 .028 0. 28  Cladophora spp. LOS NET PRODUCTIVITY P/B RATIO  .041 0. 19 2. 80  0. 85 0. 80 3 .76  NA NA NA  NA NA NA  NA NA NA  - .013 .009 3.67  .066 .087 3.51  0. 45 0. 37 2 .12  59.8 62.4 15.86  .077 0.17 3.94  TABLE  37,  CONTINUED  JUNE TO AUG  AUG TO SEPT  SEPT TO NOV  NOV TO JAN  JAN TO MAR  MAR TO APR  H. a m e r i c a n u m LOS NET P R O D U C T I V I T Y P/B R A T I O  .013 .059 0.37  - .027 .075 0 . 38  .073 .074 0. 23  NA NA NA  NA NA NA  NA NA NA  - .024 .024 0.31  .019 .011 0.30  2 . 1 10.2 1 . 59  - .006 .008 0.32  F. d i s t i c h u s LOS NET P R O D U C T I V I T Y P/B R A T I O  - .067 .047 0.51  0 . 2 8 - .079 .084 .001 1 .42 0 . 33  NA NA NA  NA NA NA  NA NA NA  -.11 .002 1 . 73  0 . 14 .065 0 . 54  7.4 8 . 5 4 . 53  .005 .026 1.64  ( u s e d C l a d o p h o r a s p pi . d a i l y p h o t o s y n t h e s i s 0 . 49 .029 NA NA NA 0 . 18 0.22 0 . 39 NA NA NA .026 2.85 3 . 77 2 . 1 2 NA NA NA  x 0.5) .043 0.11 3.67  0. 43 0.36 3.51  50. 2 47 . 3 15 . 9 2  0.13 0.11 3 . 84  SPECIES  ZONE  APR TO MAY  MAY TO JUNE  TOTAL  JUNE TO AUG  II  P o l y s i p h o n i a spp. LOS NET P R O D U C T I V I T Y P/B R A T I O  T O T A L LOS T O T A L NET  PRODUCTIVITY  271 .9 243.3  K3 O  TABLE  37,  CONTINUED  JAN TO MAR  MAR TO APR  NA NA NA  NA NA NA  NA NA NA  NA NA NA  JUNE TO AUG  AUG TO SEPT  SEPT TO NOV  NOV TO JAN  H. s e s s i 1 e LOS NET P R O D U C T I V I T Y P/B R A T I O  1 . 22 1 . 14 0.51  - 1 .05 0 .51 0 . 25  0.08 0.64 0 . 16  C. V a n c o u v e r i e n s i s LOS NET P R O D U C T I V I T Y P/B R A T I O  0.13 0.14 0 . 29  0 . 50 0 . 15 0 . 30  .073 .027 0. 20  SPECIES  ZONE  APR TO MAY  MAY TO JUNE  TOTAL  NA NA NA  0.63 1.16 0 . 94  1.11 0.92 0. 50  82 .0 185 . 1 2 . 36  NA NA NA  0.17 .057 0 . 24  .016 .031 0 . 24  JUNE TO AUG  III  TOTAL TOTAL  LOS NET  Note:  (1) g C md" (2) g C m" y - ' (June NA = n o t a v a i l a b l e  120.4 2 0 2 .4  PRODUCTIVITY  1  !  38.4 . 17.3 1 . 27  1  1982-June  1983)  ' •  0.91 0.63 0.40  .093 .016 0.11  242 Total generally  productivity  Species other and  34), of  30.1  < Helby  (316.4) < Wizard  than  g C rrr  2  di st ichus year"  (342.3)  contributed  between  i n Zone I I I at Haines  1  (Table  while these secondary/annual s p e c i e s had p r o d u c t i v i t i e s 5.89-72.4 g C r r r  109.3  g C nr  year"  2  year"  2  1  at Helby  at Wizard  1  but  s i m i l a r at Haines and Wizard At  Nudibranch,  total  Ulva  2  (39.95 g  2  and  C 2  nr  Polysiphonia  N^ l a r i x  was approximately  year" .) and Zone I I I  (202.4  1  ,  Cladophora  year" ).  2  1  spp.,  and  spp. accounted f o r most of the p r o d u c t i v i t y i n  Nudibranch/Zone II (Table 37), Zone III (185.1 g C n r Annual  1  1  1  ,  year" )  2  year" ).  y e a r " ) and lowest i n Zone I (81.5 g C n r  fenestrata  10.31-  P r o d u c t i v i t y of  (10.3 g C n r  productivity  equal i n Zone II (243.3 g C n r C nr  (Table 35)  (Table 36).  L. d i f formis was g r e a t e s t at Helby  g  sites  i n c r e a s e d with i n c r e a s i n g wave exposure:  Haines(252.8)  2.85  i n Zone I I I of the s h e l t e r e d  P/B  2  while  H^ s e s s i l e  dominated  year" ). 1  ratios  in  sheltered  F\_ d i s t i c h u s  ranged  between 2.65 and 4.41.  P/B r a t i o s were lowest i n the Zone I  p o p u l a t i o n s and h i g h e s t  i n the Zone  were  little  However,  the  differences  in  lowest  ratio  P/B  the  II  populations;  ratios (1.45)  between was  there sites.  observed  in  243  Nudibranch/Zone  I.  The  P/B  ratios  F. d i st ichus biomass "turns over"  indicate  1.5-4.4 times each year.  P/B r a t i o s i n Cladophora spp. ranged between Helby/Zone  between  20.5  and  of  26.8.  s p e c i e s were g e n e r a l l y l e s s than at  13.95 at  II and 17.97 at Helby/Zone I I I (Table 35).  f e n e s t r a t a showed a high turnover ranged  that  biomass;  P/B  4.0.  P/B  Ulva  ratios  r a t i o s i n the other Hedophyllum  sessile  Nudibranch had an annual P/B r a t i o of 2.36 (Table 37). Differences  in  were apparent i n Ratios Zone  were I  the  highest  plants,  the  P/B r a t i o s f o r each time  sheltered  i n the f a l l ,  reflecting  d e s i c c a t i o n on photosynthesis calculations.  In  F^ d i st ichus  contrast,  interval  populations.  winter and s p r i n g i n the  the  possible  effects  r a t e s as i n c o r p o r a t e d i n t o the P/B r a t i o s i n the Zone II and  Zone III p o p u l a t i o n s were g r e a t e s t during the summer. was  little  seasonal  of  variation  in  the  P/B  There  ratio  of  Nudibranch/Zone I F\_ d i st ichus (Table 37). Daily  productivity  (g  Cm"  2  d a y " ) showed a seasonal 1  p a t t e r n s i m i l a r to that of the P/B r a t i o s but  the  pattern  d i f f e r e d between study  discussed sites.  above,  At Haines,  d a i l y p r o d u c t i v i t y during the summer i n Zone II (2.77-4.08 g C m"  2  day" ) was 2.1-3.6 times that of Zone  (1.13-1.31 in  I  1  g  C m"  2  day" ). 1  Zone I p l a n t s (0.44-2.75 g  In c o n t r a s t , f a l l / w i n t e r C  m"  2  day" )  were  1  times that of Zone II p l a n t s (0.44-2.75 g C irr 34).  F^ d i st ichus  2  rates  1.1-4.2  day" ; 1  Table  At Helby and Wizard, d a i l y p r o d u c t i v i t y i n Zone II was  always Daily  greater  was  also  not during P/B  the  the  the  ratios  daily  summer,  a l l  these  35)  greatest  during  magnitude  to  herbivory,  seasonal  exceeded  net  actively  probably crops.  productivity decreased those  in  early  showed  was  species  i s  standing  spring  most  very  and  summer  carbon,  observed  (march  Most  of  throughout Helby/Zone  the III  36) were  fixed  tissues, the  although  reduced  etc.),  also  spring,  LOS  (wave algal  comparing and  net  interval.  action standing annual  reflects  i n spring/summer showed  carbon  the macroalgae  factors  losses,  species  to April)  t h e summer  I I I (Table  during  when  crops 1982.  of  important)  annual  net  productivity  ( l o s s e s of  external  total  in  1982.  thus,  obvious  variation  during  spp. i n  Except  ratios  However,  constant  erosion  in  (Table 37). P/B  seasonal  greatest  term  greatest  studied.  t o Novemember  productivity;  the  and  t h e summer,  maximum  Daily  o f t h e LOS  fixing  I during  i n Wizard/Zone  wave  Helby  H_j_ s e s s i l e  little  relatively  patterns.  being This  , which  Cladophora  August  35 a n d 3 6 ) .  III at  p r o d u c t i v i t y was for  larix  The  showed  i n Zone  species.  and  (Tables  i n Zone  generally  was  I  summer  there  P r o d u c t i v i t y of  (Table  were  Zone  winter.  of the other  vancouveriensis  year.  the  early  p r o d u c t i v i t y was  for  than  and  fenestrata  during  due  in  and net d a i l y  and  for  P/B  greater  the f a l l  ratios  spring  Except  C.  that  p r o d u c t i v i y o f F\ d i s t i c h u s  Wizard but  than  1983  a -LOS v a l u e  the vs in  In was  F\  d i st ichus  calculated  values  were  interval  varied  observed  at Haines  Helby/Zone  I  value  observed  LOS  was  rate  sites  with  in  was  Zone  rates  observed  Because which  may  winter  of  abiotic  per  distichus  .  The  (F=10.506  2,8ldf;  in  the  rate  was  also  Wizard/Zone  I,  LOS  always  positive  and  A  three  DAILY  algal  negative sheltered  i n Zone  Wizard,  m  I at  but  data  for  intertidal  factors  following  was  -LOS  1  over  the  factors lack  0.095(H2O-T)  MULTIPLE-R  =  0.45384  -  of  of  the  species  analysis  of  daily  substrate  performed  for  day" ),  and  most  significant  p=0.0001) 2  of environmental  regression of  2  number  productivity,  spring  ( g C m"  PROD =  in  -LOS  only  on  with  regression  the  selected Fucus  equation  productivity  a l lsites  and  zones,  obtained:  NET  LOS  noted the  interval. a l l  was  value  January-March  II at  large  environmental  di st ichus  ( a -LOS  -LOS  Negative  i n Zone  multiple  productivity  zone.  during  I I I at Helby  the  early a  spring  in Haines/Zone I I I .  influence  and  studied,  i n Zone  a  and  i n the March-April  in March-April.  were  I  and Helby  calculated  and  i n which  the s i t e  in March-April);  Nudibranch  F.  t h e month  0.22(WAVE SE  =  EXP)  +  0.99657  0.83  of was  246 Note  that  coefficients  the  for  Multiple-R  water  exposure  (r=-0.39560)  equation  accounts  in  p r o d u c t i v i t y of  daily  and  partial  temperature  are quite  for only  (r=0.23338)  low.  20.6%  of  correlation  Thus,  and  the  wave  regression  the observed  variability  distichus .  Discussion  The  observed  compatible  with  of  (1980).  Littler  the  thin  h" ) a n d dry  wt"  and  1  fenestrata  were  C g dry  observed  and  mg  mg  i n the  the  C  1  g  coarsely 1  h" ). 1  articulated  (0.26-0.86  americanum  wt"  18-19)  C g d r y wt"  in  in  i n the  (Figures  Vancouveriens i s  in Halosaccion  mg  (0.25-0.86  C  mg  g C  1  i t  should  in photosynthetic  variable  20a,b)  lowest  hypothesis  (0.97-4.53  Fucus d i s tichus  is  greatest  mg  were  (0.54-2.20  rates  h" ).  However,  on  spp.  rates  (Figure  Corallina  were  (1.45-6.26  Cladophora  larix  rates  and  1  d r y wt"  based  rates  sessile  algae h" )  1  changes  Photosynthetic  Neorhodomela  coralline  g  form-function"  Intermediate  Hedophyllum  wt"  "morphological  thick-bladed  Photosynthetic  dry  photosynthetic  filamentous 1  branched  of  Ulva  h" ).  1  perennial and  the  sheet the  1  pattern  thallus i n those  form. species  be  noted  rates  that  can  blur  Photosynthetic with  higher  d i u r n a l and any  rates  rates.  seasonal  distinctions were  also  Although  more this  247 may  have  been  due  to c o m p l i c a t i o n s  oxygen c o n c e n t r a t i o n s , of  classifying  photosynthetic rates  were  i t a l s o demonstrates  algae  rates.  into  broad  in  low  amer icanum  saccate  thallus,  (1980) would have been e x p e c t e d  the  and  elevated  limitations  groups  In a d d i t i o n , v e r y  observed  p a r e n c h y m a t o u s and  in measuring  based  on  photosynthetic  .  T h i s a l g a has  according  to  t o have much h i g h e r  a  Littler r a t e s of  photosynthesis. Although  seasonal  apparently C.  occurred  vancouveriensis  and  Pye  (1968)  some  concluded  (including  relatively  unaffected  range  in  in  of  that  Ulva by  respiration  species  ), t h e - c h a n g e s were  macroalgae  normal  differences  F^ d i st ichus  not  temperature to  and  ,  great.  Newell  rates  i n seven  respiration  lactuca  temperatures  (  rates  Fucus  sp.)  were  fluctuations within  the  which  are  the  plants  exposed. The are  comparable  Johnson dry  observed  wt-  found 18°C,  et a l . h"  1  1  rates  r a t e s of p h o t o s y n t h e s i s with  distichus  0.61  and  1.23  respectively, for this  ranging  between  reported  f o r a number  Brinkhuis,  0.8  1977b).  from C a l i f o r n i a  found  (1974) r e p o r t e d  f o r F\ of  those  (0.40  and of  mg  a value  of  ' Quadir  mg  C g dry  mg  0.9 et wt"  C g dry  wt"  ( K i n g and  wt"  1  1  workers.  ± 0.13 al. h"  1  mg  h" ; 1  1  h"  1  C g  (1979) at  10  Photosynthetic  r a t e s were n o t e d  C g dry  F^ d i s t i c h u s  previous  and  fucoids  Lower  by  plant.  2.5  for  rates  have  Schramm,  and  been  1976b;  i n F^ d i s t i c h u s Littler,  1980)  248  and  for  Fucus  serratus  c a n a l i c u l a t a in Scotland converted  from  the  E\_ s p i r a l i s  (0.20-0.35 mg C  ,  g  and  dry  Pelvetia  wt  h" ,  - 1  1  a u t h o r ' s o r i g i n a l u n i t s ; Schonbeck  N o r t o n , 1980).  King and  photosynthetic  rates  (converted)  L.,  Schramm  of  (1976a)  0.45-3.48  i n F\ v e s i c u l o s u s  .  mg  observed C  g  In f u c o i d s ,  maximum  dry wt"  h"  1  i n the a p i c a l p o r t i o n s of the b l a d e s  decreased  the base of the p l a n t ( K i n g and  1976a; B r i n k h u i s , 1977a,b). use  plant  material  portions,  so  Care was  comprised  the  of  observed  and  Schramm,  taken i n t h i s study both  1  photosynthetic  r a t e s were g r e a t e s t towards  and  blade  photosynthetic  to  and  stipe  rates  were  r e p r e s e n t a t i v e of whole p l a n t s . Seasonal changes i n p h o t o s y n t h e t i c small  and  not  (p<0.0l).  clearly  Nudibranch  r a t e s were g e n e r a l l y  distinguished  by  S-N-K  F^ d i s t i c h u s a p p a r e n t l y  analysis  had  greatest  r a t e s i n the summer, but data are l a c k i n g f o r the w i n t e r early spring. found  Previous  large  seasonal  Quadir et a l .  s t u d i e s w i t h f u c o i d s have  i n F\ d i s t i c h u s d u r i n g J u l y at 18°C Maximum  rates  in  ( B r i n k h u i s , 1 977a) were the  Ascophyllum and  F. s e r r a t u s  and was  winter. greatest  photosynthetic  than i n January at  nodosum, ecad  vesiculosus  observed i n the s p r i n g and fall  generally  differences in photosynthetic  (1979) r e p o r t e d h i g h e r  In  rates. rates 10°C.  scorpioides  (Brinkhuis,  1977b)  summer, w i t h lower r a t e s i n  contrast, in  and  photosynthesis  the w i n t e r and  s p r i n g (King and Schramm, 1976b).  Fucus  lowest  vesiculosus  in i n the from  249 the  Baltic  winter  showed  and  appear  to  spring  show  environmental between This  a  (see  photosynthetic  in  and  may  August  in  have rates  water  the  photosynthesis (Table  more  photon  flux  indirectly  (and  daylength  on  di st ichus The  plants showed  seasonal  as  well  as  area.  patterns  of  1977a,b,c).  than  the  photosynthesis  changes  seasonal  was  in  to  during  to  lower  this  the  time.  only  environmental  account  net In  net  the  daily  factors  temperature  daylength  July  significant  abiotic  i n water  net  seasonal  a n a l y s i s of  by  in  limitation the  by  hourly  variation  due  during  regression  net  changing  regression  changes  the  to  thus  may  have  than  absolute  equations  may  therefore  for  influence  the  photosynthesis  in  the  of  sheltered  .  various -  geographical  contributed  accurately?) daily  same  Nitrate  influenced  density;  the  probably  selected  strongly  species  daily  temperature  Seasonal  same  net  observed  fall,  Fucoids  the  the  was  multiple on  29).  Thus,  daylength.  photosynthesis plants,  apparent  1976b).  the  responses  Brinkhuis, in  during  of  different  rates.  differences  been  more  photosynthesis  factor  in  differences  rates  Schramm,  variety  in  also  d i s t i c h u s were  Helby  and  species  result  Seasonal  F.  wide  different  might  daily  (King  constant  conditions, within  productivity  F.  relatively  daily  responses  photosynthesis and  diurnal  indicative  of  parameters P/R  ratios,  biochemical  for PSE  the -  Helby  generally  adjustments  to  minimize on  the  effects  photosynthesis  lower  in  negative  positive  photon  (PSE)  and  ambient  found  Grac i l a r i a concluded be  to  light were color been  not  were  at The  decrease  monitored the  J.  and  Ag.  by  in this  carotenoids Zavodnik  seasonal  with  study,  were  equations  of  but  PSE  to a i r . net  accommodation  to  the  and  and  Ramus  winter  Ulva  sp.  increases  in They  would  photosynthesis  Although  pigment  distichus  was  mechanism Winter  observed  wave  and  seasonal  species.  pigment  from  between  Borgeson  F^  exposed  during  similar  (1973),  pattern  differed  time  and  temperature,  Rosenberg  levels  these  a  rainfall  indicating  and  significant  water  observed  decreased.  this  The  with  i n t e g r a t e d net  in  correlated  regression  in  so  not  Nudibranch  of  winter,  operating  with  conditions.  effect  positive  Photosynthetic  winter;  cent  (Forskall)  temperature  chlorophyll (Don)  light  the  the  during  also  i n c r e a s e d pigment  that  and  per  generally  concentration  the  observed  and  environment  were  a i r temperature.  correlations  were  the  significant  nitrate  were  f o l i ifera  limit  had  photosynthesis,  seasonal  (1982b)  with  density,  daily  and  in  ratios  increased during  correlations  gross  changes  P/R  seawater  negative  flux  Negative and  with  correlations  exposure  The  summer  correlations  efficiency  seasonal  rates.  the  correlations  of  levels  darker may  in  have  maxima  in Fucus  as  in  virsoides  photosynthetic  rates  levels.  photosynthesis  that  in  the  for  net  daily  i n F^  sheltered  d i st ichus plants.  photosynthesis  in  Nudibranch the  F\  Helby  while  plants:  to  effects.  the  lack  Nudibranch not  noted  of  study  may  be  daily  di st ichus  June  and  seasonal  from  concordance  photosynthetic  rates  Seasonal productivity sites.  Daily  Zone  I  at  I  Haines  of  2  Zones  Wizard,  greatest  regression  but  Helby. in  .  the  d i s t i c h u s standing  in  phenomena  varied  for  organic  elevated  does  between also  photosynthetic  observed  were  in  this  with  net  and  greatest  1983, was  (1973)  while  also  weight  was  maximum  i n net  at  greatest  sheltered  highest  in  the  fall/winter daily  reflecting  other  times.  study  during  the  Nudibranch,  daily  the  of  at  in  reported  and  observed  substrate)  1982,  in  greatest  III  summer  in  .  also  intertidal  was  weight  organic  vi rsoides  crop  the  (1973)  seasonally  Zavodnik  At  perhaps  occurrence.  March-May  was  had  equation  seasonal  during  II  air  data  Zavodnik  content  i n F\_  to  in  effect  results,  the  productivity  in  and  m  exposed  Organic  differences (per  spring/summer  of  negative  spring  the  weight  1982.  those  functional relationship  Nudibranch,  August  a  early  that  general  di st ichus  from  anomalous  differences  more  had  time  environment  (organic)  F^  and  the  photosynthesis.  sheltered  F.  the  cent  v i r s o i d e s , so  of  Ash-free  at  reflect  different  rather  suggest  and  Fucus  per  winter  between-site  rates  was  of  accurately  and  also  temperature  These  plants,  photosynthesis  F.  water  a i r temperature  positive due  d i s t i c h u s were  sites in  the and Zone  productivity the P/B  decreased ratios  showed  a  seasonal  productivity constant  at  at  to  the  generally  in  I and  Zone  of  I at of  implicate  plants of  than  a  those  winter  Haines daily  wave  (Chapter  action  F\_  increased  are  as  distichus  the  rates  of  nutrient  moderate  plants  spiralis  Norton and  P_;_  Zones  the  (1979)  is  rate  summer.  et  canaliculata  I  ca.  standing  II  crop  seasonal at  Wizard,  pattern. greatest  25%  (Johnson  this  (1983) a  few  ^to  the  levels  found weeks  that of  limitation.  accommodations growth  for  Nutrient  nutrient  nutrient  that  but  photosynthesis  after  reported  rates  level,  a l . , 1974).  Thomas  such  were  Photosynthetic  of  by  addition,  apparently  reduced  and  summer  plants  In  and  due  rates  accommodations  enhanced  also  the  observed  above  and  desiccation  was  similar I  the  shows  were  in  Zone  desiccated  (Johnson  stress  uptake  (20-30%) and  in  in  high  also  desiccation  by  Schonbeck  exposed  in  the  a l . , 1979).  a  sites  plants.  and  desiccation  maintain  when  and  productivity  d i st ichus  distichus  et  increasing  faced  in  3)  in  stress  II  influencing  F\_  Quadir  can  hours by  daily  relatively  photosynthesis  Zone  productivity  1974;  uptake  of  were  sheltered  rates  decline  al.,  plants  daily  in  exposed  with  the  photosynthetic  plants  several  that  differences at  net  the  the  to but  desiccation  in  decline  F.  II  Photosynthesis when  sites,  observed  calculated  lower  lack  pattern  et  the  However,  the  sheltered  assumptions  reducing 50%.  of  Zone  the  similar  Nudibranch.  Part between  the  pattern  during  in the  summer hour per  was of  every  can  just  as good  every  twelve  twelve  hours.  In a d d i t i o n ,  recover  t o maximum  apparently  rates  after  level  a period  plants  when  the plants  hours  a s when  of exposure  (Schonbeck  were  submerged  submerged upper  more  eleven  level  submerged  hours fucoids  photosynthetic  completely  and Norton,  one  than  1978; D r i n g  lower  and Brown,  1982). Despite effects  of  adjustments  fucoids  desiccation  stress  productivity, is  effected  wave  i t would  adversely  action  Wizard, similar  may  the  seasonal  to that  reduced).  as  at  Nudibranch, a n d show  wave  action  thallus in  increased The those  wave  scorpioides (0.24-0.75  shore  plants  (although  wave  action  i s even  Standing  crops also  ( s e e Thorn,  increased  i n Zone  pattern  are limited  1983) a n d  I at  productivity  show  greater  by  still,  a r e much  than the  at  the  greater  differences  biochemical  mechanisms  i s  productivity  and p r o d u c t i v i t y  probably  assimilatory  by  daily  C  productivity  Brinkhuis  (0.6-1.4 g  as  still  in  changes  i n response  to  action.  observed  reported  Where  daily  seasonal  the  I F^ di st ichus  stresses,  photosynthesis  limit  l i m i t a t i o n on  of  Where  the photosynthetic  to  pattern  and the p l a n t s  structure  Zone  stresses.  these  a different  sites.  make  and n u t r i e n t  that  these  of lower  still  sheltered  by  reduce  is  reduced  appear  may  nr  2  g  are greater  than  for  A_^_ n o d o s u m  ecad  (1977c)  C  d a y  rates  irr 1  )  2  and  day  - 1  by  )  and F^ Neill  vesiculosus (1977)  for  F.  spiralis  (0.50  (0.67  g C rrr  due  to  day  2  g  C  ).  - 1  in  photosynthetic  rates  of  (1977c).  based  on b i o m a s s  productivity (1973) 4.02  g C m"  rrr .  Both  2  are F.  to  to  LOS  rate  plants F. was  for  crop,  may  (see Brinkhuis,  and d a i l y  found  in  were  underestimated Zavodnik to  be  o f 6 7 5 g d r y wt  productivity  the  that  however,  1977c).  crop  as  and  F\_ v i r s o i d e s  on a s t a n d i n g crop  study  have  sheltered  term  di st ichus  also  (losses  etc.).  values  Zone  due  Negative  observed  to LOS  II  the  increases  observed  noted  varied and  in  1982.  in  Helby,  and  spring  in  A negative Zone  enough  1983  and  of the s p r i n g  March-April  Nudibranch  wave  F\ d i s t i c h u s  January-March  I plants.  the  indicating  not high  The t i m i n g  sites:  i n the  were  early  between  and Wizard/Zone  observed  the  in  herbivory,  values,  rates  i n t h e summer  also  were  photosynthetic  were  at Haines  never  in this  certainly  levels,  (1977) d a t a ,  which  differences  the measured  occasionally  crop  p r o d u c t i v i t y of  those  of t i s s u e s ,  standing  Neill's  based  o f t h e LOS  account  canaliculata  populations.  Seasonal  that  and  1  comparable  the standing  d i st ichus  erosion  daily 1  similar  magnitude  were  by up t o 50%  day" ,  2  " )  standing  changes,  estimated  day  2  The d i f f e r e n c e s a r e a l m o s t  differences  Brinkhuis  rrr  I  -  i n Zone I Zone LOS  II term  F\_ d i s t i c h u s  populat ion. Most standing  of crop;  the  losses  the remainder  were  the result  cannot  of decreases  be c o m p l e t e l y  in  attributed  to  DOM  excretion,  of  herbivory  been  (see  stored  have  growth rates  in  of than  lower Also,  small more  temperature  for  mature  and  organic  growth  increased  in  contributed  the  early  observed spring  plants  and  are  (Fain  and  Murray,  response  spring  to  the  Zone  results  of  capable  making  the I  appears  that  limited  by  and  Zone  the  major  were  increased  wave  grow  under  Thorn,  1983).  light  and  concentrations),  metabolized  light  and  values  -LOS  to  II  populations.  net  during the  This  value  removing  the the  studies  and  F_;_ d i s t i c h u s  months; and f\  is  changes  photosynthesis  fall  in  in  seasonal  a l l  may  explain  the  to  used  observed  of  that  and  temperature  decreased.  hypothesis  Positive  action  to  reduced  photosynthesis  productivity during  photosynthetic  to  adjustments  observed  the  the  p r o d u c t i v i t y suggest  temperature.  productivity  timing  of  during  c a l c u l a t e d -LOS no  crop  elevated  when  offer  term  were  concentrations  I can  LOS  standing  1982;  been  early  have  nitrate  result  adapted  may  have  also  the  higher  molecules  of  and  the  have  (in  of  large  nitrate  calculations  light  which  levels  the  of  The  may  effects  ambient  some  probably  enzyme  differences in  The  when  ambient  spring.  between  carbon  addition,  were  nitrate  have  summer  minimal  increased  the  and  fixed  reproduction.  germlings  winter  , as  In  conditions  and  these  low.  and  hypothesized  the  spring  i f pigment  fall  4)  into  the  light  Chapter  were  gone  increases  the  during  concentrations may  despite  i t  in and  thus  winter  were  distichus  from  the  intertidal,  desiccation  and  by  stress  low  in  t h e summer.  desiccation  and n u t r i e n t  conclusions  are supported  observed  that  Sound  greater  was  Fucus light  di st ichus  populat ion To  my  (0.5-1.50 I976ab), g  1  to  1  sessile  rates  seasonally were  1  (1.4  1980; L i t t l e r sessile rates  t o June  a n d none  significantly  March-July. by  ambient  plants  may  limits  data  grow the  seasonal  (Table  30).  correlated  a n d Schramm,  1973), 1  1980),  g  dry  and wt"  1  are similar  photosynthesis  pattern,  Respiration  photosynthesis with  Egregia  h" ; Littler C  C  study.  daily  strong  1  mg  and Arnold, in this  Lamour.  ( 1 . 5 8 ± 0.37 mg  and Pearse,  (0.7-2.8  However,  King  C g d r y wt"  of the d a i l y  rates of  (Huds.)  ( L . ) C. A g .  and net  on  sessile.  1  and E ^ m e n z i e s i i  a  who  i n Puget  high  however,  h ~ , converted;  pyri fera  for  These  not l i m i t e d  under  i n Laminar i a d i g i tata  mg  in April  are  individual  Hedophyllum  Setchell  showed  in  a r e no p r e v i o u s  Towle  Photosynthetic H.  there  1  found  rates  reduce  (1983),  d i st ichus than  action,  may  and  and p r o d u c t i v i t y .  C g d r y wt"  1974),  o f Thorn  and thus,  h " , converted;  Littler,  those  rates  Macrocystis  laevigata  h" ;  crop  in  mg  d r y wt"  Murray,  Wave  action  t h e summer.  of tagged  i n winter  knowledge,  photosynthetic  by t h e r e s u l t s  concentrations,  standing  photosynthesis  Wave  i n October-February  rates.  concentrations  during  photosynthetic  nitrate  maximal  stresses  growth  or temperature  seawater at  mean  nutrient  any  of  with  in  maximal  d i d not  vary  parameters the  abiotic  environmental multiple  factors  regression  significant, difficult  as  productivity greatest  in  study  in  based  calculations  vary  conflicting  productivity  available  larix  ,  Chapman of  C  Considering  m"  1  day"  1  a n d Nova  37).  on crop,  However,  elongation  were  of  g C irr  properly  errors  was  i n the  throughout  sessile  d i dnot  Despite  these  data  from  Scotia,  the  i n H^  observed  sessile  .  the l i t e r a t u r e are ,  Neorhodomela  , and L e a t h e s i a daily  Further  1  americanum  reported for  year" ).  2  evaluate  patterns  woodi i  (1983)  based  constant  difformis .  productivity  d i f f o r m i s i n Nova  the differences i n standing  sites  crops  the rates  Scotia.  between  found  rates  the  i n t h e two  are comparable.  While content  190  Halosaccion  Cryptosiphonia  0.017g  studies  for  were  are  p r o d u c t i v i t y c a l c u l a t e d by t h e two  (ca. to  (Table  months.  photosynthetic  and Goudey  Bamfield  between  highly  data. ,  of blade  content  and photosynthesis  Comparable not  - they  the  of standing  (or, i f there  and o r g a n i c  a r e needed  though  of winter  a n d summer  of  distichus  and e s t i m a t e s  summer  similar  31),  sessile  on m e a s u r e m e n t s  observations,  experiments  in  - see R e s u l t s  was  (Table  results  Nudibranch  spring  late  period)  The  due t o t h e l a c k  significantly  methods  the  measurements  greatest  the  with  productivity  photosynthesis were  analysis  to explain  Daily  monitored.  seasonal  d i f f e r e n c e s were  o f H^ amer i c a n u m  observed  , photosynthesis  was  i n the organic constant  for  all  the  organic in  days content  spring.  Net  November  spring Table  was  greatest  in  N^  and  a  much  of  action winter. this  II  wave N_^  l a rix  the  Littler reported of  and  higher (3.0-3.6  C  g  in  August  the  early  hypothesis.  winter  from  rates  Daily productivity during  lacking  for  June-  a  strong  winter).  apparently  Nudibranch;  removed  thus  wave  l a rix p r o d u c t i v i t y during data  needed  to  the  verify  available. in Coral1ina  Kutz.  range and  1-980);  weight)..  early  suggesting  rates  for  storing  111/Nudibranch,  greatest  photosynthesis  Murray,  these  Littler  ash-free  rates wt'  1  and  are  and  3.6  mg  Littler,  var C  g  1980;  similar  to  those  ( i f expressed  in  terms  Arnold  during 1  0.4  1974;  values  h" )  vancouveriensis  between  vancouveriensis  photosynthetic mg  the  (Littler  Arnold,  here  ash-free  1  this  1983,  during  N_;_  Zone  lowest  in photosynthesis  was  are  in  As  the  greatest  great.  data  biomass  i s not  h"  37)  limited  (Decaisne)  not  June-August  action  Photosynthetic  1  were  (but  have  wt"  to  (Table  and  hypothesis  ash-free  34;  observed  However,  chilensis  Table  were  they  in  observed  changes  pattern  may  was  support  1982  the  value  also  and been  growth  p r o d u c t i v i t y was  , but  performed.  have  later  some  Nudibranch/Zone  Increased  for  may  lend  larix  seasonal  amer i c a n u m  -LOS  were  i n August-November  III/Haines,  which  September  experiments  compounds  (Zone 37),  H_;_  daily  Seasonal  in  which  April-June,  carbon/nitrogen  to  on  (1980)  October  compared  with  reported  and  December  March  and  June  (0.4-1.4  Seasonal  mg  data  April  and  and  during  discussed  were  apparently  also  and  Littler Many  various 1.4  and  Brinkhuis, Littlerj  mg  6.17  ±  0.74  respectively, those  Brinkhuis fall/winter  summer  daily  Zone I I I .  standing  due  to  crops  extreme  productivity calculations  (0.02-  were  the  by  (1980;  0.07-0.20  ; the 1  h"  1975;  g d r y wt"  1  tr  1  fenestrata  in this  study  (1977b) in  values and  Arnold  et  and  a l .  2.46.±  and  0.41  Murray  mg  C  These  f o r U^  rates  fenestrata  reported  summer  photosynthesis  by  (1974) 1  rates  range  in  between  Murray,  1974;  Murray,  1980;  observed  g d r y wt" at  for  day" ).  2  (1979)  (converted) .  found  photosynthetic  (Littler  1  those  g C nr  reported  Quadir of  with Littler  quantified  Ulva  rates  summer  comparable  Buesa,  minima  in Nudibranch  p r o d u c t i v i t y i n C_^ V a n c o u v e r i e n s i s  g d r y wt"  i n U^  observed  the  Haines/Zone  The  1980).  C  II and  "die-back".  have  1977b;  mg  during  California  of  C  photosynthetic  22).  C_^ V a n c o u v e r i e n s i s  of  workers  9.2  3,  Arnold  species  and  greatest  effects  in  Corallina  i n C_^ V a n c o u v e r i e n s i s was  (Figure  was  for  constant  net  1  officinalis  collected  .  relatively  the  day" )  2  officinalis  1  in Nudibranch/Zone  reduced  daily  g C nr  h" ) i n  1  i n August-September  the  calculated 0.14  be  September  stress;  show  wt"  photosynthesis  in Chapter  desiccation  C.  , but  September-November  III, As  not  productivity  Daily in  g ash-free  could  Vancouveriensis between  C  10 are  1  h"  and  1  and  18°C,  similar  to  . maxima U^  lactuca  and  Fall/winter as  measurements  the plants  were  productivity sporadic the  was  "blooms"  summer.  maximal Ramus  rates  this  study  influences  harmful The  range study  reported  Buesa  with  and Murray,  (1975) C  values ranged  Schramm,  for  g  dry wt for between  1976b;  to those  - 1  rates  in  1.5 a n d  Wallentius,  reported  here  contrast  differences  et a l . ,  to  during  rates f o r of  values  (Littler,  1979).  rates  of  1.85  ±  fuliginosa  Kutz.,  glomerata  (L.)  C g dry wt  1978).  to  photosynthesis  t h e range  Cladophora  in  important  productivity  i n Cladophora  high  observed  cali fornica Wille  11.4 mg  of  temperatures  photosynthetic  Baltic  nutrients  September-November  the monthly  of d a i l y  1  of  In  reduced  are within  h~  and  been  found  1974; L i t t l e r  observed  Rosenberg  were  have  water  Ulva  also  pulses  pulses  but  was  t o the maintenance  may  He a t t r i b u t e d  in this  Littler  similar  .  26).  productivity.  (1981)  compared  observed  previously  and  and  e f f e c t s of elevated  fenestrata  Kutz.  Similar 2)  Bottom  July  the  while  sp.  Daily  throughout  IL f e n e s t r a t a  (Table  essential  months.  observed  intermittent  on U. ' f e n e s t r a t a  during  mg  that  (Chapter  studies,  July.  1982  fenestrata  August-November,  were  of  on  these  during  fenestrata  were  i n Ulva  U_;_ l a c t u c a  0.47  during  content  reported  in  1973;  of IL  t h e summer  growth  U.  found  greatest  Organic  (1982a)  these  n o t b e made  i n August-September  during  rates  rarely  could  These  f o r Cladophora  - 1  h~  1  (King  rates . are  spp.  Littler  (1980), h"  however,  reported  i n Cladophora  1  graminea  Photosynthesis between  observed  i n October.  spring  and  June-August organic  1982.  macroalgal here, F.  values  previously  Laminariales. found  have  not reported  previously,  levels  (desiccation, ratio  the water high  movement  although P/B P/B  ratios past  ratios ratios  ratio  was  1.6. water  They  benthic  under  such  marine  studies  i s  of  reported  the range of  to  with  fucoids  a s 4.4  observed  decreased or  to higher that  found ,  are costly  a  while  levels  exposure  stressful and  with  stress  (1979)  lonqicruris  plants,  and  similar  action)  more  of  Fucales  a n d Mann  conditions  1983.  are also  concluded  movement  in  productivity  generally  exposed  in  increased  the values  studies  (wave  highest  productivity  as high  Gerard  in plants  was  various  i n sheltered Laminaria  t o some  survival  P/B  during  i s within  1  for  greatest  previous  y" )  2  of disturbance  intensity  beneficial for  P/B  o f some  m"  rates  summer  Annual  nutrients).  o f 2.7  annual  .  during  38.  C  annual  daily  with  annual  f o r F^ di st ichus  increasing  P/B  g  1  relatively  between  together  reported  The  those  here  increased  Table  (56-740  wt"  lower  content  correlation  not observed  in  C g dry  with  p r o d u c t i v i t y was  of the r e s u l t s  given  d i st ichus  September,  similar  productivity,  i s  mg  s p p . was  and o r g a n i c  and  s p p . was  summary  and  Daily  A  o f 0.3  Cladophora  summer  content  Cladophora A  April  low r a t e Coll.  in  constant  the  a  of to  than  adjustments i n terms of  Table  38  Summary o f d a i l y  SPECIES  PERENNIAL  and annual  ANNUAL PRODUCTIVITY (q C m-2 y - 1 )  150  ANNUAL P/B RATIO  Corallina officinalis v a r c h i1 e n s i s vancouveriensis  2.9-17.3  menziessii  Fucus d i s t i c h u s ssp. edenatatus Fucus  s p i ra1 i s  Fucus  vesiculosus  Fucus v i r s o i d e s  2 . 1 - 2.. 8 0.6 - 1 .. 4  1 .8  REFERENCE  56-740 964-1752 182 . 5 348 150  0.07  - 0.. 20  0.02  - 0.. 14  0.04  - 0.. 15  0.11  - 4. 08  0. 50  0. 24 - 0. 75 4 .02  Westlake (1963) B r i n k h u i s (1977c) Wassman & Ramus  22:. 1  Cod i urn f r a q i 1 e  Eqreqia  DAILY PRODUCTIVITY (q C m-2 d-1)  macroalgae.  SPECIES  A s c o p h v l l u m nodusom ecad s c o r p i o i d e s  Corallina  n e t p r o d u c t i v i t y by m a r i n e b e n t h i c  Littler 1.3-1.6  This  ( 1973  e t a l . (1979)  study  Li t t l e r  e t a l . ( 1979)  1.5-4.4 2.8  This Thorn  study (1983)  1 . 99  Neill  2. 3  Guterstam (1981) B r i nkhu i s ( 1977c )  (1977)  Zavodnik  (1973)  TABLE  38,  CONTINUED  SPECIES  Hedophy11 urn s e s s i 1 e Himanthalia  elongata  Laminaria  hyperborea  Lami n a r i a  1ong i c r u r i s  ANNUAL PRODUCTIVITY ( q C m-2 V- 1 )  190  DAILY PRODUCTIVITY ( g C m-2 d-1)  0.51  -  1 . 16  2.4  2.71  989 . 2  ANNUAL P/B RATIO  12.25  640-1320 3.9  120  Various  1750  Laminariales  Macrocyst is pyr i f e r a  54-81  Pel v e t i a  244 .6  : •  Various  species  Neill  study (1977)  1.6-2.7  Johnston Mann  3.8-20.4  0.67 1.5  -  21.4  (1974)  W e s t l a k e (1963) H a t c h e r e t a l . ( 1977) G e r a r d & Mann ( 1 9 7 9 )  6.8 canaliculata  This  J u p p & Drew  143-428 288-576 Lam i n a r i a s a c c h a r i na  REFERENCE  Aleem  e t a l . ( 1977)  (1972b) (1956)  Towle & Pearse 1.98  Neill  (1973)  (1977)  Johnston  e t a l . (1969)  TABLE  38, CONTINUED  SPECIES  ANNUAL PRODUCTIVITY (g C m-2 y - 1 )  ANNUAL/EPHEMERAL  spp.  H a l o s a c c i on amer icanum  28-229  larix  U1va  ca1i forn ica  U1va  fenstrata  U1va  1actuca  Various  REFERENCE  0.17-2.8  Rice  a n d Chapman  27.9-72 .4  0.03-0.80  14.0-18.0  This  study  8.4-10.2  0.01-0.08  1.6  Thi s  study  10.3-40.0  0.017 .008-0.43  3.6-5.0  Chapman & G o u d e y T h i s study  30.7-51.9  0.01-0.44  2.3-5.0  This  Leathes i a d i fformi s  Neorhodomela  ANNUAL P/B RATIO  SPECIES  C h o r d a r i a f1 a g e 11i f o r m i s Cladophora  DAILY PRODUCTIVITY (g C m-2 d-1 )  .002-.013 2.8 45.9-109.3 35  ephemerals  This  e t a l . ( 1979) (1973)  study  Brinkhuis Lapointe  0.1-1.3  (1983)  study  Li t t l e r Littler 20.5-26.8  0.03-1.30  (1982)  (1977c) e t a l . (1981)  265  productivity. F.  A  similar  situation  should  productivity losses  be  stressed  f o r most  during  the  that  species June  sessile  ).  decreased  algal  standing  crops  As  discussed  effects  of  productivity those  of  the  the  by  photosynthetic  (Khailov  occurs  in  of  used  excretion.  Other  and  only four  cent  a l . , 1966;  1977;  Pregnall,  excreted  losses  net (Table  the  have  are  LOS  annual  of  the  summer  of  been  but  due  to  Maximum  probably  term,  net  notable  1983-1983.  population  1969;  of  at  this  least may  be  dynamics  DOM.  more  productivity 37),  a  large  some  the  carbon  and  and  the in was  carbon  fucoids  and  of  kelps  however,  the  overestimated  DOM  methods,  have  ranging  between  one  fixed  in  photosynthesis  1975;  Hatcher  et  fixed  L_^  by  a l .  (1977)  lonqicruris  kelp  much  higher  than  of  carbon  the  H_j_  Brylinsky,  the  fraction  levels  rigorous  Craigie,  However,  high  1969);  have  excretion,  Thus,  very  Sieburth,  using  Harlin  of  by  may  DOM  of  35%  observed  studies  1983).  ca. as  have  workers,  per  that  annual  (a  result  may  of  excretion  in these  rates  et  annual  matter  low  (Majak  proposed  this  total  period  during  system  in  workers  Burlakova,  techniques  found  3,  the  the  observed  this  total  1983  annual  rates.  organic and  than  is  event  changes  number  dissolved  in  observed  complicated  A  Nino  levels  less  This  in Chapter  El  calculated  1982-June  is  1983.  the  was  exception  was  also  distichus . It  the  apparently  sessile, total  where annual  fixed  in  266 photosynthesis organic  may  have  F^ d i s t i c h u s ,  summer,  but s t a n d i n g  Chapter  3).  accounted growth  during as  ambient  needed  carbon  fixed  the  i f  excreted  as  dissolved  light,  factors  productivity observed  the e f f e c t s  calculations  a time  -  desiccation  in  been  and  due t o t h e  lost were  may  canopy limiting  have  been  determinations  experiments and  and n u t r i e n t  of  evaluating carbohydrate  and p h o t o s y n t h e s i s ,  in  relation  conditions,  apparently  on  selected  .  However, for  were  are  rates  a  crop  was  in  the  of the due  productivity  by o n l y by  daily  obviously  (see Chapter  and l i g h t  with  portion  this  usually  with net  environmental  small  c a n be l i m i t e d  i n t h e summer  produced  the equations  analyses  areas,  ecologically  abiotic  only  standing  temperate  stress  have  carbon  equations  and r e g r e s s i o n  Photosynthesis  photosynthesis  replacing  in productivity;  of a l g a l  (see  to direct  and  accounted  variability  stable  hypotheses.  regression  i n F\_ d i s t i c h u s  generally  protein  temperature  photosynthesis  the  could  physiological  these  during  in  the fixed  uptake,  greatest  concentrations  between  nitrate  were  term  In a d d i t i o n  rates,  was  Fj_ d i s t c h u s  significant,  meaningful, daily  LOS  nitrate  DOM.  to evaluate  Very  at  levels  interactions  metabolism,  to  crop  t h e summer,  excretion  the  in  productivity  understory Also,  excreted  to  The  for  of  plants.  DOM  been  matter.  In  growth  also  3). one  factor  nutrient  or  or temperature i n  the  winter.  the  However,  effects  rates;  of  the  these  reduced  levels light  disturbances  and  and  may  be  enzyme  such  as  wave  random  storms  from  intertidal  while  result  in  (Gerard  and  Mann,  1979).  torn fall of  from and  the  may  temporal  and  North,  1982a), ambient be  For  so  of  1980;  nitrate  from some  et  concentrations  other  during pattern  environmental  have and  observed  algal 1977;  Rosenberg  between  readily  seasonal  a l . ,  calm  action  ambient  et  plants  are  wave  uptake  (and  the  water  relatively  the  a l . , 1982;  correlations  biomass  in  workers  Hatcher  plant  plants  heavy  the  longer;  growth Wheeler  and  Ramus,  productivity  and  factors)  not  might  found. The  above in  equations.  Productivity  metabolic algal  the  observations  differences  and  the  nitrogen  1977;  Gagne  larger  addition,  example,  Craigie,  that  In  by  "uncoupled"  uncoupling  (Chapman and  storms. be  conditions.  summer,  intertidal  winter  growth  and  the  to  much  intensity  s t r u c t u r a l changes After  with  adjustments  much  high  uptake  increase  take  remove  limit  desiccation;  can  would  to  nutrient  contrast,  constant  would  spring  In  would  movements  of  adjust  by  activities  action  and  conditions  rapidly  enhanced  temperatures.  infrequent the  can  stressful conditions:  photosynthesis  pigment  plants  ecological  processes standing  is  also relevance  the  result  responding  crop,  which  partly  is  to  of of  the  explain  the  regression  interaction  environmental  influenced  by  the  of  stresses,  disturbances  268 as  well  as s t r e s s .  possible, and  but  are  they  standing  stochastic  Phenotypic  crop  (see  effects  difficult  positive  produce  effect  the  (1966) to  time.  which  Such rapid  increases  changes  changes i n wave  with  action  productivity  lower,  Nudibranch,  however,  greatest was  i n t h e Zone  not  assemblage  much  in  the  by  than  a n d P/B At  .  thus  meaningful respect  to  correlate  the  during  the  spring  and winter  ratios the  highest  III  turf", that  with  inversely  was  higher,  diversity  although in  sites,  i n t h e upper  assemblages.  and  found .  were  sheltered  Diversity  Zone  sessile  relation  productivity.  productivity  II " a l g a l  greater  dominated  and  as  Margalef  time;  with  the f a l l  and p r o d u c t i v i t y  b y F\ d i s t i c h u s  of  i n a more  levels  a  that  not  in  more a c c u a r a t l y  diversity.  lowest  dominated  crop  have  alleviating  were  notion  during  productivity  algal  was  may  The  not s u r p r i s i n g  derivatives  in nutrient  standing  general,  diversity zones  analysis  in algal  In related  an  the  are  by  be u s e d  t o be c o r r e l a t e d  that  may  photosynthesis.  should  growth  disturbance)  action  growth  for daily  convey  is likely  wave  are  1979).  as a  equations  productivity  magnitudes  observed and  that  factors  with  those  (acting  stress  on p l a n t  Mann,  I t i s thus  regression  as  stated  productivity way  stress.  productivity  comprehensive  action  plant  to  effects  and  also,  on  desiccation/nutrient  varying  Gerard  o f wave  t o measure;  adjustments  but At were  productivity t h e Zone I I I  269  Lapointe  et a l .  productivity  and  "successional" northwest the  larger  community "early of  the  further  study  Spain. sizes  of  compared  influence area.  the  on  the  algal  in  the a l g a l  intertidal  algal  in  the  in  along  a  community  in  Chapter  viewed  5  regarding  productivity wave  community  crops  When  ( i . e . wave  that  pattern  "climax"  standing  plants.  the hypothesis  increase  the observed  lower  diversity  an  diversity  plants  ephemeral  presented  support  in  attributed  with  stress),  noted  in a mussel-raft  They  influencing  desiccation  major  gradient  results  also  decrease  successional"  factors  to  (1981)  kelp of the  in  light those  exposure  data  would  action  organisation  to  is  and seem the  i n the  270 CONCLUDING  The  main  increased  goal  end, a l g a l  but  interacting,  (2)  photosynthetic  levels: rates,  the standing  physiological  crop i s  synthesis,  wave  salinity,  a difficult t h e many  necessitate carbon  (e.  representative  and  to a  interaction  longer  and v a r i a b i l i t y .  degree  o f e r r o r due  problems  c a n be d r a w n  a t some  time  may  problems the  PQ,  short-term  by t h e p l a n t s ,  regarding  which  (constant  In  factors  These  (light,  productivity  periods.  experienced  uptake,  algal  assumptions  environmental  of  (herbivory,  e t c . ) and the e x t r a p o l a t i o n of  of those  which  calculated  conditions  methodological  taken  To  data.  processes  large  of  crops,  nutrient  Estimating  an  different,  standing  the  environmental  subject  to  magnitude  conclusions  ecological  of photosynthesis  of  of  role  system.  productivity,  result  etc.).  and  on t h r e e  macroalgal  the use of s i m p l i f y i n g  g. m o n t h l y )  both  studied  (3)  acquire  intertidal  (photosynthesis,  practical  measurements  of  the  and  task,  contents,  measurements  and  to  magnitude  rocky  (1)  etc.),  etc.),  action,  the  was  and p h o t o s y n t h e s i s  processes  competition,  to  of  p r o d u c t i v i t y was  Productivity  is  research  productivity in a  this  protein  this  understanding  macroalgal  using  of  REMARKS  interval addition, not  be  i n terms limit  the  relationships  271  between  algal  seasonally  the  as  on  processes  entities,  adjust  productivity,  be  changes  to  in  and  a  expected  to  in  the  environmental f l u c t u a t i o n s of  have  Accommodation  changes  are  environmental  expected  algae.  seasonal  macroalgae  to  short-term  would  the  to  only of  a  limited  physiological  environment  are  much  apparent. The  rates,  methods the  standing these  crop,  and  parameters  their  used  in  this  relationships  environment.  the  to  Thus,  magnitude  impact  more  living  ability  conditions. small  ecology,  f l u c u a t i n g environment.  However, show  physiology,  relation studying  interactions, observed  to  and  photosynthesis  productivity, and  a  seasonal  individual  were  proposed  seasonal  in  fluctuating patterns,  and  explain  the  to  patterns  algal  patterns  seasonally  these  hypotheses  magnitudes  examined  between  photosynthesis,  in  By  study  in  macroalgal  productivity. The  observed  calculated reported of  standing  productivity  previously  in  p r o d u c t i v i t y , the  (100-2000 standing  g  C  crops  heterogeneity means). showed  In only  nr  the  range  2  y  1  showed  (standard contrast, a  crops, values  photosynthetic were  literature. of for a  values  fucoids large  degree  of  and  and  values  in the  kelps)  usually  rates  the  i s very  amount  were  photosynthetic  to  However,  reported  deviations  moderate  similar  rates,  and  of >  within  variability  case large algal  spatial 50% a  of  the  species  (standard  272 deviations  were  relatively  constant  difference ( mg  in  attributed Thus, and  Hedophyllum  by  variability  productivity  daily  70-90%  of the observed  light, daily  factor  rates  the  productivity seasonal  the  accounted  sense.  uncoupling  conditions,  was  and/or  This of (2)  algal  (despite can  be  crops.  distichus  environmental  standing  may  water  crops,  be i n f l u e n c e d  temperature  equations  relatively to  was  equations very  these may  for  photosynthesis.  constant seasonal  by  during the changes  have  little  been from  strong  daylength.  f o r standing  parameters  growth the  accounted  in  c o n c e n t r a t i o n s , e t c . , and net  determined  for  in  1  50-75%.  of  i n net daily  adjusted  regression  variation  "ecological"  and the  nutrient  photosynthesis  d' ) ,  2  i n the regression equations f o r  were  temperature,  contrast,  Fucus  of c a .  productivity  variance  F^ di st ichus  irr  standing  for  "error"  I n F\_ d i s t i c h u s ,  g C  applied)  algal  values  an  how  photosynthesis,  thus,  in  the  photosynthesis  (  factors  were  of  calculations  photosynthesis,  reflect  significant  Photosynthetic year;  have  of  of the r e g r e s s i o n analyses  the environment.  net  (1)  the  and  Because  crop  i n the productivity  sessile  mean)  of the u n i t s  and c o r r e c t i o n  productivity,  only  the  year.  1  and net d a i l y  the  the  used  results  factors  of  d~ ) and standing  1  the reported  The  and  to  30%  throughout  of the e r r o r assumptions  <  the magnitude  C g dry wt"  most the  usually  of  the  and  ambient  c r o p and observed  made  due t o two  In  little  factors:  environmental  dependence  of  algal  273 standing  crops  photosynthesis the  sum  of  of  point  Wave both  of metabolism  the interaction  (1) must  action  is  magnitude  much  wave  impact  Phenotypic  a  rather  three  adjustments  i n the Nudibranch  accommodation  action  is  evidence  the  productivity, model  and  the  not  suggest  that  winter,  while  the wave  results  action  action  environmental  productivity  costly  a n d Mann,  in  1979).  increases  infeasible  in and  quantitative  action of t h i s  on factor  productivity,  of  limits  this  factor  (1)  algal  varied  also  study  algal into  is  a  thus  stress  appears  affecting  the  i n the f a l l  is limiting  to  be  intertidal  distributions, along  f o r F\_ d i s t i c h u s  productivity  desiccation/nutrient  Wave  structure:  predicting  chronic  apparently  but a r e  and random  as  weather.  to  and  Gerard  incorporation  have  possible.  However,  summer.  or  i n terms of  adaptations  wave  level.  may  Conclusive  of  i s the  importance  "moderate"  energetically  effects  explaining  probably  to infrequent  impractical.  of  storm  possible,  (see also  probably  evolutionarily  influence,  o f more  are  The  time,  physiological  d i st ichus,  of net p r o d u c t i v i t y  However,  factors.  at the  while  at a  o f many  one s e v e r e  exposure  factor  net p r o d u c t i v i t y )  and g e n o t y p i c  occurred  wave  wave  addition,  ( i . e.  months  of  one  stochastic  and d u r a t i o n ; as  In  by o n l y  be e v a l u a t e d  levels  terms  action.  c a n be l i m i t e d  total  result  on  wave  the  i n the major  community  abundances, exposure  and  and  gradient;  274 (2) the  invertebrate wave  d i s t r i b u t i o n s and abundances  exposure  upper i n t e r t i d a l  gradient;  (3) d e s i c c a t i o n  but increased  alleviate desiccation could  thus  stress. be  wave  s t r e s s i n the  action  Although  no  experimental  herbivory  apparently as  a  has rough  appeared  The observed p a t t e r n  explained  on  i n t e r a c t i n g e f f e c t s of wave a c t i o n and  productivity;  along  (Zones I and I I ) l i m i t e d the growth of many  macroalgal s p e c i e s ,  diversity  varied  the  little  of a l g a l  b a s i s of the  desiccation  manipulations  stress.  were  performed,  on  macroalgal  effect  estimate,  to  herbivores  probably  consume l e s s than 5% of the annual macroalgal p r o d u c t v i t y of this  intertidal  presence  of  reproduction productivity. and  system.  a  Substratum  F_;_ d i s t i c h u s  heterogeneity,  canopy,  and  and recruitment have greater Additional  e c o l o g i c a l , are needed  experiments, to  more  the  variations  impact  on  in  algal  both p h y s i o l o g i c a l  fully  understand  p r o d u c t i v i t y of the macroalgae i n t h i s i n t e r t i d a l  the  system.  275 SUMMARY  1) of  The  the  productivity,  intertidal  Bamfield, period  B.C.,  1982  representative The  zones  based  on  from  the  upper  2) of  1  Fucus  the  and  were  the based  abundance  wt  woodi i the  ,  Ulva  more  II,  by  a  species  (  and  of  where  Zone  F\_  was  di st ichus  Hedophyllum  fifteen  month  study  sites,  divided I,  were  into  II  three III,  and  a l l measurements  in an  Zones  of  of  spring  and  sessile  in  F^  of  di st ichus was  and  annual  and  The  Zone  canopy  sites  summer ,  I,  Zone  Cryptosiphonia  algal  characterized in  II  sheltered  difformis  , etc.).  and  crops  increased,  the  I  extensive  standing  Leathesia  site  was  i t formed  III  of  exposure,  abundant  exposure  series  vicinity  Five  and  structure  division.  most  wave  a  (designated  this  fenestrata  exposed  population Zone  As  2  characterized  site  achieved  irr .  the  wave  shore)  was  sites,  decreased.  ephemeral  on  di st ichus  sheltered  dry  lower  in over  in  each  presence  occasionally kg  at  community  1983).  gradient  shore  to  studied  August  a  algal  community  were  -  of  examined.  calculations  algal  Canada  (June  d i v e r s i t y and  an III.  community  by "algal  a  at  small turf"  in  276 3)  A l l species  minima less  in  standing  abundant  Multiple  during  4)  The and  in  I  Zone  L^ of  sufficient  F.  crop]  at  sitkana the  than  were  summer  crop  on  1982.  selected  equations  50%  of  herbivores These  sites  to  the  which  variance  and  but  were  animals may  limit  species,  Zone  diversity  species  exposed II  sites site  proposed  and  was turf"  and  predicted  [ exp(H')  richness  "algal  exposure  pattern was  Algal  and  the  wave  .  study  numbers  sheltered  the  produced  less  species  with  standing  winter  in  were  have the  .  Littorina  most  been  abundant  present  in  abundance  probably  had  little  and  based  of impact  distichus .  5)  the  of  abundant  secondary/ephemeral on  and  crop.  only  scutulata  compared  factors for  maxima  a d d i t i o n , most  1983  analyses  accounted  standing  In  summer  environmental  generally  spring/summer  crop.  regression  abiotic  algal  showed  by  that  were  greatest  in  different:  Zones  Zone  When  stress,  hypothesis  algal  in  of  diversity  standing II  The  was  greatest  diversity  the  of  pattern  plotted  Huston was  on  I and  III.  diversity  assemblage.  desiccation the  least  1/q,  in  against showed  (1979). result  of  a It  the  277 interactive with  effects  biotic  canopy  Diurnal  distichus.  was  during  Annual  populations  740  g C nr  per  m  intertidal factors  Multiple-R  Positive year,  net d a i l y  but  the spring  greatest  analysis  substrate  wave  i n t h e Zone sites  of d a i l y on  i n net d a i l y  (220-  abiotic  equation,  year,  stress  were  and not l i g h t  E\_ d i s t i c h u s  thus  fall  during  the  and summer.  the  rates  seasonal  result  intensity  productivity  the  the  the  low.  apparently  photosynthetic  photosynthesis  during  nutrient/desiccation  the  but  very  i n the winter  Hourly  during  daylength,  that  observed  I and  productivity  selected  significant  action  crops.  and  summer.  throughout  slightly  action  analysis)  at the sheltered  a  correlated  was  only  wave  strongly  i n Fucus  productivity  varied  i s proposed  was  monthly  was  standing  It  distichus  coefficient  increased  in  and t h e F^  correlation  algal  differences  stress,  measured  and  produced  limited  differences  desiccation  regression  was  Regression  1  environmental the  (multiple  o f F_^ d i s t i c h u s  of  2  was  photosynthesis  productivity  y" )..  2  and  (herbivory  photosynthesis  temperature  greatest  action  influences.  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H. formula.  1968. Ecology  W i n o k u r , M, species.  1948. Amer.  taxonomic J. Bot.  Use of biomass 49:153-156.  study of the genus 43:1409-1420.  units  Photosythesis relationships J . Bot. 35:207-214.  in  Shannons  of  Chlorella  Zavodnik, N. 1973. Seasonal variations in rate of p h o t o s y n t h e t i c a c t i v i t y and c h e m i c a l c o m p o s i t i o n of the littoral seaweeds common to the North A d r i a t i c . I. F u c u s v i r s o i d e s (Don) J . Ag. Bot. Mar. 16:155-165.  299 APPENDIX  Knowledge photosynthesis calculation  A -  PHOTOSYNTHESIS-IRRADIANCE  of  the  and  and  by  Numerous  is  and  a  light  intensity  work  on  1982)  and macroalgae  that  the  seasonally.  PS  vs  aspects objective  of  I  in  the was  photosynthesis  Included accounts of  to  been  reviewed  i n each  for  the  of  these  observed  photosynthesis  some  saturating  the light  to  intensity  with level.  at  which  1957)  and  (photoinhibition).  both  phytoplankton  (Harding  (Ramus a n d R o s e n b e r g , relationship  may  study  to i d e n t i f y  that  saturated  Both  were  diurnal  studied.  photon so that  flux  shown  diurnally  experiments  vs I r e l a t i o n s h i p area.  et e l . ,  1980) h a v e  vary  of the following  relationship  became  have  developed  (IK, as per T a i l i n g ,  o n t h e PS  the  these  primary  f o r the i n h i b i t i o n of p h o t o s y n t h e s i s at  The p u r p o s e  information  macroalgae  include  intensities  Recent  been  of  to the  macroalgal  have  rates up  i s saturated  accounting  light  obtain  in  parameters  photosynthesis functions  which  increase  Additional  higher  models  rates  i s fundamental  of  (1981).  parameter  proportional increasing  Tett  between  sunlight  t h e PS v s I r e l a t i o n s h i p ;  Lederman  models  incident  comprehension  productivity. describe  relationship  CURVES  for and  corrections  was  to  selected seasonal  The  density  and  at  main which  could  be  300 made  to  obtain  productivity  Methods  and  more  (Chapter  photosynthesis of  photon  and  determine  light  the  (PS  rates  only  flux  on  days  of  to  Incubations  begun  at  the  sets day  of to  relationship Each bottles four  measure  and  surface  (Ramus  and  of  were  algal  0930  diurnal  set consisted  (without  performed  water  i n the  run  of  the  of  experiment.  sequentially in  the  wrapped  screening  during  PS  wet  table  Flowing  Inlet.  300  with (1  were  bacterial  temperatures  Bamfield  of  three clear  macroalgae)  in a  rates  vs  I  1980).  density  Station. water  day  bottles  and  high  photoinhibition.  changes  Rosenberg,  neutral  maintained  were  were  and  saturated  the  diurnal  Curves  cover  for  on  BOD  6).  net  modified  estimate  cloud  ensure  between  essentially  Chapter  minimal  replicate  Marine  to  check  phytoplankton  Bamfield  bottles  for  three  used  incubations  test  bottles  experiments the  h  incubation  layers  control  1.5  were  to  and  relationship  I)  (see  density  were  the  vs  procedure  photosynthesis  Three  of  6).  to  photosynthesis determined  estimations  Materials  Experiments  versions  accurate  ml  BOD  one  to  mm  also  mesh);  used  metabolism.  to The  in a  greenhouse  at  water  around  the  ±  that  the  1°C  of  301 Light using  a  attenuation LICOR  Corporation). was  Model  for attenuation  bath,  thus  actually  the  during  any  etc.),  so  during  I  lower  incubations),  nature.  in  the  were  or  were  in  the  constantly  changing  changes,  clouds,  a r e t h e mean  Although  light  and  the  and  PFD  levels  procedure  i n determining  light  curves  water  the plants used  PFD u s e d  methods  the  the  temperature  produced  should  be  o f t h e PS v s I r e l a t i o n s h i p o f t h e m a c r o a l g a e Rosenberg  and  Ramus  i n t h e PS v s I c u r v e s determined the  Photosynthesis  Integrator)  No c o r r e c t i o n s  (diurnal  the usual  incubation  the  which  incubations,  nm)  by  was  period.  the  the  those  PFD  of  (PAR 4 0 0 - 7 0 0  bottle  to  than  values  from  1  r e l a t i o n s h i p ( i . e . constant  the  foli ifera  PFD  Instrument  attenuated  s~ .  BOD  incubation  the  2  determined  LI-500  light  irr  uE  of  MODEL  of  due t o t h e  during  differed  difference  and  LICOR  addition,  single  representative in  during  f o r the incubation  employed vs  flux  as  are  In  that  fluctuated  PS  total  values  exposed  calculations.  values  density  a  was  (Lambda  flux  with  expressed  Meter  photon  by t h e p e r c e n t a g e  screening, made  the  (measured  multiplied  185A Q u a n t u m  Absolute  c a l c u l a t e d as  period  due t o t h e s c r e e n i n g  Ln s i t u  laboratory was m e a s u r e d  of Ulva  (under (under as  (1982b)  reported  spp. and  fluctuating constant  oxygen  little  Gracilaria conditions)  conditions).  evolution  using  a  302  Beckman  Model  dry  wt"  h"  and  Parsons,  1  0260  using  1  site  day  from  filtered  one  the  not  not  report  The  h  plants  ,  held  equipped effects Whole  fenestrata  Hedophyllum individual  C  g  Strickland  of the  screening use  to  with  The and  as  in  6).  l i t e r  or  -  .  1  carbon  Johnston dioxide  using  of plant  up  hours  flowing  seawater  of wound-induced plants  where  Leathesis razor  blade.  h  diurnal were  bottles  deficiency  used the  g d r y wt for  the  results.  troughs  i n the  and bubbled  a i r so  respiration  of C o r a l l i n a  used  a  24-48  ( 1 9 6 9 ) d-id  t o 0.3  material  the  levels  Specimens  i n water  with  at  the  f o r 24-48  and  shaken  collected  influenced  were  was  c o n c e n t r a t i o n s i n t h e BOD  experiments  with  water  atmospheric  was  the  study  equilibrate  s h o u l d not have  sessile thalli  collected  collected.  handled  g d r y wt  24-h  was  offshore  (see Chapter  so t h e amount  were  possible  minimized. Ulva  1  and  nutrient  incubations  greenhouse the  any  were  m  material  algal  1.0  10-50  seawater  Algal  so that  -  1963;  experiments  before  experiments  during  l i t e r  (Westlake,  Nitex  hour  i n the  exceed  problems  jjm  experiments  photosynthesis  1.5  45  1979).  did  the  the plants  oxygen  algae  in  which  dissolved  to size  1.20  the surface  for  cut  of  from  through  (Littler,  PQ  used  intervals  before  a  A n a l y z e r a n d c o n v e r t e d t o mg  1972).  Seawater previous  Oxygen  would  be  Vancouveriensis  and  possible.  Pieces  d i f f o r m i s were Apical  of  cut  from  sections  of  303 Fucus  d i st ichus  used  i n the The  , containing at least  were  (1936),  Winokur  written  as f o l l o w s  PS  1  fitted  (1948),  to  = PSSAT  t h e PS v s I m o d e l  and T a i l i n g  (Lederman  : PS = r a t e  C g d r y wt"  dichotomies,  were  experiments.  data  where  four  { a  (1957),  and T e t t ,  I/[(PSSAT)  which  Smith  may  be  1981):  +  2  of  of photosynthesis  ( a  I) ]exp0.5  }  2  per unit  biomass  (mg  h' ); 1  PSSAT  =  light-saturated  (maximum)  rate  of  p h o t o s y n t h e s i s;  Note  that  I  = photon  a  = an e m p i r i c a l l y  or  data  above  those  Linear data  levels limited)  points  the  photosynthesis PSSAT.  density  summed  on  which  PSSAT v a l u e regression  PFD  where were  PFD  the  into  the  analysis,  visually  but  only  estimated  value  (Piatt  and  as  performed  on  i f this  saturation  linear  (light-  Jassby,  1976).  by p l u g g i n g  generated  of  designated  below  ascending  t o be  saturation  (MIDAS) were  was c a l c u l a t e d equation  ) ;  light  apparently  curve  1  PS=PSSAT/(2)expO.5  for  corresponding  (PFDSAT)  _  constant.  a n d t h e mean  were  p o r t i o n of the  Saturation  2  regression analyses  points  and  which  apparent  were  ( u E m" s  determined  I K = P S S A T / a a n d IK=I  Those at  flux  by  t h e mean  the  regression  linear equation  304  was  statistically  was  estimated  value  could  regression where  IK  parameters  the  of  recorded.  latter  i f  P S S A T was  a  was  The  experiments  were  apparently  calculated  n o way  IK  significant  as the lowest  There  PFDSAT  vs I.  In those  photosynthesis used,  cases,  o f PS  only  produced.  of PFD  as the  PFD  value  to determine  a  curves.  of the experiments  are presented data  i n the  a n d t h e a s s o c i a t e d PS  in Figures lower  impossible.  large y-intercepts  for  i t was The  firm  values  diurnal  However, t h e  Leathesia  range  the  curves  difformis  a  photosynthesis  was  June  1983  greater  suggest  2  for  I The  s" ) 1  the  of a and that  the  relationship  those  species  the data  obtained  . with  experiments Incubation  than  39.  concerning  o f t h e PS v s I  densities  vs  100 u E r r r  However, t h e low v a l u e s  g e n e r a l l y agree  21  (<  conclusions  possible to calculate  PSSAT the  flux  28-34 a n d T a b l e  PFD  f o r a a r e not i n d i c a t i v e  s u b s a t u r a t i n g photon  during  the curves  p o i n t s a n d PFDSAT  was  vs I curves  where  6).  rates  t h e c o n s t r u c t i o n of any  values at  had been  other  and D i s c u s s i o n  Results  make  from  in a l l  calculated  at the lowest  i n these  lack  be  equation  PSSAT  Results  PS  also  of the data  where or  visually  saturated  observed mean  significant;  a n y mean  (see 3  Chapter  PSSAT  for  photosynthetic  305  Figure  28  Photosynthesis-irradiance for  Fucus d i s t i c h u s  curves  from Zone I  at Helby.  A) 29 Sep  1982  B) 11 Apr  1983  C)  1983  5 July  1.4  A  2 9 S e p t 1982  i 200  1 400  1 600  1 800  1— 1000  PFD ( ^ / E i n m - ' s - ) 1  O 0"N  1  2 00  1  1  400  PFD  600  !  800  (jtEin-nr'-s- ) 1  I  1000  1  1  1300  C - 5 July 1983  I 2 00  1 1 1 400 600 800 PFD ( j / E i n - m - ' - s - ) 1  — I 1000  1  1 1600  Figure  29  Photosynthesis-irradiance f o r Fucus d i s t i c h u s  curves  from Zone I I  at Helby.  A) 24 May B)  8 July  1983 1983  24 M a y 1983  _ 200  ,  -i  400  600  PFotf/Ein-m-'-s-*)  1  800  —i 1000  1  1  1600  B - 8 July 1983  >  200  1  400  — r  i  600  PFD(*/Ein-m  - 2  800  s ) - 1  •  1  1000  1  1  1600  Figure  30  Photosynthesis-irradiance for  curves  Fucus d i s t i c h u s from Zone I at Nudibranch.  •  29 Sep  1982  •  A Aug  1983  1.4H  Fucus  1.0H  0.6H  0.2-^  200  —i  r—  1  400 600 800 PFD (//Ein-nr'-s- ) 1  —i  1000  r  1600  314  Figure  31  Photosynthesis-irradiance f o r Hedophyllum (21 May  curve  sessile  1983).  1.4  Hedophyllum  1XH  0.6-r*  0.2H  200  400  600  800  PFD ( j i E i n m - ' s - ) 1  —I 1000  1  1 1600  Figure  32  Photosynthesis-irradiance for  Corallina  curve  vancouveriensis  (29 A p r i l  1983).  1.0-  Corallina  0.6-  0.2—I— 200  —r— 600 800 400 PFD (^Einm-'-s-')  —I  1000  1  1  1600  Figure  33  Photosynthesis-irradiance for Leathesia  curves  difformis.  •  = 21 June 1983/Incubation 1  •  = 21 June 1983/Incubations  2+3  O  = 29 J u l y  1+2  •  = 29 J u l y 1983/Incubation 3  1983/Incubations  3.0H  Leathesia  2.4H  .O _  •  1.6-1 I  o  . - /  a  O  o •  o.8H  o  o  „  _ _ _ _ _  ° ;0  •  1  °  _  '  _  * -  •  o  ••  _ u  0  O  200  °  O  .  *  -  o  -  a  1  1  400  1  600  800  PFD ( / r E i n - n r * - * - ) 1  1  1000  1  1  1600  320  Figure  34  Photosynthesis-irradiance for Ulva  fenestrata.  (7 A p r i l  1983)  curve  4.0H  Ulva  3.OH  >  ? o  2.0-  01  E  V)  a.  1.0-  — T —  200  —I  —r— 800  1—  400  600  PFD(*/E in m  - 2  s"'  T  1000  1  1  1600  322  T a b l e  3 9 .  C a l c u l a t e d  a n d  e s t i m a t e d s e 1 e c t e d  o f  V a n c o u v e r A p r 11  2 9  F u c u s  P S  v s  I  r e l a t i o n s h i p  m a c r o a 1 g a e .  1 )  at  P S S A T 1 2 1  3 1  i n  •  l e n s i s  1 9 8 3  -  Z o n e  3 6 0 "  0 . 6 4 ± 0 . 1 6  5 0  0 . 9 6 1 0 . 1 6  4 3 0 '  1 . 1 5 ± 0 . 1 0  1 7 5  0 . 7 9 ± 0 . 1 6  1 . 0 0 * 1 0  '  1 7 3  9 . 5 5 * 1 0  '  7 3  I  2 9  S e p t e m b e r  11  A p r i l  5  1 9 8 3  Z o n e  I I  M a y  1 9 8 3  1 7 5  0 . 9 0 * 0 . 2 7  J u l y  1 9 8 3  4 5 0  1 . 1 1 1 0 . 1 4  2 4 8  -  1 9 8 2  1 9 8 3  J u l y  H e l b y  N u d i b r a n c h 2 3  -  Z o n e  S e p t e m b e r  4  A u g u s t  H e d o p h y l l u m 21  L e a t h e s i a  I 7 5  1 9 8 2  1 9 8 3  0  8 2 * 0 . 2 0  1 5 0  0 . 8 3 * 0 . 2 1  4 2 0 "  0 . 9 8 1 0  s e s s i l e M a y  1 9 8 3  1 0  9 . 2 7 x 1 0  •  d i f f o r m i s  2 1  J u n e  1 9 8 3  I n c u b a t  i o n s  1  I n c u b a t i o n 2 9  J u l y  &  2  3  1 5 0  0 . 8 7 1 0 . 2 5  1 0 0  1 . 6 3 * 0 . 3 2  1 9 8 3  I n c u b a t  io n  I n c u b a t  i o n s  1 2  6  3  1 5 0  0 . 9 4 * 0 . 3 9  2 0 0  1 . 7 4 1 0 . 9 9  1 2 5  2 . 8 8 1 0 . 5 5  f e n e s t r a t a 7  N o t e s :  t h e  d 1 s t i c h u s H e l b y  U l v a  o f  i n t e r t id a l  P F D S A T 1  S P E C I E S / D A T E C o r a l l m a  p a r a m e t e r s  A p r i1  1 9 8 3  ( 1 )  u E i n r r r ' s  1  ( 2 )  m g  C  g  w t -  ( 3 )  m g  C  g d r y  *  d r y  c a l c u l a t e d  w t  '  u s i n g  h  1  h  1  1  P F D  r e g r e s s 'i o n  e q u a t i o n  a n d  P S S S A T  I s e e  M e t h o d s  1  1  13  323 rate  observed  this any  plant. of  were  the no  There  430  lower  nr  plants  uE  and  III  at  affected  reported for study  three was  the  visual  ,  the  (see  values  also  limited  by  (these  in  there  PS  vs  I  .  species  estimated and  the  at  availability  3).  Chapter Ulva  five  of  abundant Fucus  <  suggested of  during  have when  in  the  Zones  II  distichus  ,  are  reduce  the  Hedophyllum  light  may  (PFDSAT  that  may  a t t e n u a t i o n due  Fucus  green  rates  light  Niemeck  (1980),  generally  suggest  fenestrata  probably  to  the  water  photosynthesis and  photosynthesis  possible effects  in  1966).  Kanwisher,  see  at  IK  maximum  most  by  Murray  PFDSAT  observed  p l a n t s were  However,  of  of  360  were g e n e r a l l y  and of  between  Vancouveriensis  and  slightly  ranged  values  estimates  PFDSAT v a l u e s  s a t u r a t i o n of  experiments) low,  that  Self-shading  distichus  in  Arnold  1  difformis  column. F.  s' ).  2  Nudibranch;  only  difformis  estimated  Corallina  high  Leathesia  for  photoinhibition  in  values  photosynthesizing  and  are  nr  day  photosynthesis tides  calculated,  low  be  the  sess i l e  of  differences  calculated  The  should of  Except  visually  1  the  macroalgae.  most  s~ ;  2  reported  exceeded  evidence  experiments  .  (50-200  however,  little  diurnal  P F D S A T was  pE  photosynthesis  studied.  apparent  Where  diurnal  was  species  relationships  and  i n the  at  (1978)  Mathieson 200-250 u E  nr  f o r F\_ d i s t i c h u s  175  pE  nr  that,  as  this  2  s  _  PFD  in  1  was  self-shading should  in  in 5  s"  2  1  this of  7  relatively be  limited.  324  Little Fucus  seasonal  dist ichus,  differences PFD  values  in  in  t h e PFDSAT.  The  permit  difformis,  The  between  0  a  was  to  of data  PSSAT  be  some  points  a t low  of  were  apparently  any  firm  observed i n  little  pE i r r  change  of  number of  greater  than  1500  studied  should  thus  nr  2  photon  of  the  even s  levels;  to ensure  1  -  1  .  show  macroalgae  light  s"  2  portion  pE  experiments  range  of p h o t o i n h i b i t i o n ,  of the time  in  low  evidence  most  lack  intertidal  as a s u i t a b l e  linear  appeared  these  at  on  a n d 600  as w e l l  ascending  the  saturated  concentrate  i n t h e PSSAT f o r  construction  changes  of  in  observed  the day.  results  generally  the  but there  during  photosynthesis  rates  there  Diurnal  t h e PFDSAT  should  although  d i d not  conclusions. Leathesia  v a r i a t i o n was  curve.  a t photon The  future flux  days.  at  is  studies  densities saturated  points  on  the  There  is  flux  densities  intertidal  be p h o t o s y n t h e s i z i n g  on a l l b u t o v e r c a s t  studied  obtaining  data  that  little  macroalgae  maximum  rates  


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