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UBC Theses and Dissertations

Colonies as defence in the freshwater phytoplankton genus Dinobryon (Chrysophyceae) Armstrong, Gary Dale 1985

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COLONIES AS DEFENCE IN THE FRESHWATER PHYTOPLANKTON GENUS DINOBRYON (CHRYSOPHYCEAE). by GARY DALE ARMSTRONG B.Sc. University Of B r i t i s h Columbia, 1976 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES Department Of Botany We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA A p r i l 1985 © Gary Dale Armstrong, 1985 In presenting t h i s thesis i n p a r t i a l f u l f i l m e n t of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. I t i s understood that copying or publication of t h i s thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of The University of B r i t i s h Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 DE-6 (3/81) i i Abstract This thesis addresses the idea that colony formation e f f e c t i v e l y increases the size of a phytoplankter thereby reducing grazing losses by deterring ingestion by zooplankton. It was i n i t i a l l y hypothesized that colonies of Dinobryon (Ochromonadales, Chrysophyceae) deter zooplankton grazers, and that their spring population declined either because of a drop in the mean colony size of the Dinobryon population or from an increase in the abundances of large zooplankton grazers capable of ingesting large colonies. From January to May 1983 a small dystrophic lake was sampled weekly at three discrete depths at two stations. In the samples col l e c t e d from one station, two species of Dinobryon, D. cylindricum Imhof and D. diverqens Imhof, as well as a l l zooplankton species were enumerated and morphometric variables of Dinobryon colonies were measured. The results showed that, alone, each of the o r i g i n a l hypotheses could not account for the population and colony size dynamics of the Dinobryon species present in the lake. A new hypothesis was generated from the results which suggested that Dinobryon colonies minimized grazing losses to small grazers because of increased size and to larger grazers by fragmentation upon capture. Subsequent evaluation of the assumptions of this new hypothesis, using both the o r i g i n a l data and new data from the second station, added further support to the hypothesis. i i i Table of Contents Abstract i i L i s t of Tables v i L i s t of Figures v i i Acknowledgement ix Chapter I INTRODUCTION 1 1 . PHYTOPLANKTON COLONIES 1 2. EXPLANATIONS FOR COLONY FORMATION 2 3. DINOBRYON 5 3 .1 Occurrence 5 3.2 Adaptations For Spring Appearances 8 3.3 The Function Of Colonies In Dinobryon 9 3.4 Dinobryon Population Declines 11 4. HYPOTHESES 13 4.1 Hypotheses Formulation 13 4.2 Limitations Of The Hypotheses 15 Chapter II MATERIALS AND METHODS 17 1 . FIELD SITE • 17 2. SAMPLING 22 2.1 General Considerations 22 2.2 Physico-chemical Factors 23 2.3 B i o l o g i c a l Factors 25 3. PLANKTON ENUMERATION AND ANALYSIS 2 7 3.1 Species I d e n t i f i c a t i o n 27 3.2 Phytoplankton 27 3.2.1 Samples Analyzed 27 3.2.2 Phytoplankton Counts 27 3.2.3 Limitations Of The Analysis 28 3.2.4 Colonial Phytoplankton Enumeration 31 3.3 Colony Measurements 33 3.3.1 Sample Size Of Colony Measurements 34 3.3.2 Colony Size Estimate 35 3.4 Zooplankton 37 4. STATISTICAL CONSIDERATIONS 39 Chapter III RESULTS AND DISCUSSION 40 1. PHYSICO-CHEMICAL FACTORS 40 1.1 Temperature 40 i v 1.2 Lake Transparency And Light Extinction 40 1.3 Soluble Reactive Phosphate Levels 41 2. DINOBRYON POPULATION AND COLONY DYNAMICS 47 2.1 Species Occurrence 47 2.2 Temporal Distribution And Abundance 47 2.2.1 D. cylindricum 47 2.2.2 D. divergens 49 2.2.3 V e r t i c a l D i s t r i b u t i o n 49 3. COLONY MORPHOMETRICS 54 3.1 Colony Shape 54 3.1.1 Colony Size - Temporal Variation 61 3.1.2 Colony Size - Spatial D i s t r i b u t i o n 62 3.1.3 Concurrent Changes In Colony Size And Populations 62 3.2 Temporal Changes In Other Colony Variables 68 4. ZOOPLANKTON 7 3 Chapter IV THE ORIGINAL HYPOTHESES RECONSIDERED 79 1. MODIFICATION THE ORIGINAL HYPOTHESES 79 2. REFORMULATION OF THE HYPOTHESES 80 2.1 An Explanation For Colony Size Declines 80 2.2 Applying The New Hypothesis To The Results 83 3. OTHER POSSIBLE EXPLANATIONS 85 4. THE REVISED HYPOTHESIS 89 Chapter V REVIEWING THE NEW HYPOTHESIS 90 1. ASSUMPTIONS OF THE NEW HYPOTHESIS 90 2. MATERIALS AND METHODS 90 2.1 Zooplankton Gut Analysis 90 2.2 Colony Size Frequency Distributions 92 2.3 Station II Phytoplankton Samples 92 3. RESULTS 93 3. 1 Gut Analysis 93 3.2 Colony Size Frequency Distributions 93 3.3 Station II Population Dynamics 99 3.4 Station II Colony Size Dynamics 99 3.5 Station II Single Empty Loricas 101 4. DISCUSSION 102 V Chapter VI SUMMARY AND CONCLUSIONS 104 BIBLIOGRAPHY .. . 110 APPENDIX A - EFFECT OF SAMPLING PUMP ON COLONY SIZE 125 APPENDIX B - TAXONOMIC IDENTIFICATION - SOURCES 127 APPENDIX C - DAILY MEAN/MAXIMUM TEMPERATURES AND HOURS OF BRIGHT SUNSHINE FOR THE COMO LAKE REGION 128 APPENDIX D - IRRADIANCE DATA AND EXTINCTION COEFFICIENTS 129 APPENDIX E - SOLUBLE REACTIVE PHOSPHATE CONCENTRATIONS ..130 APPENDIX F - CELL VOLUME ANALYSIS 131 APPENDIX G - COLONY ABUNDANCES - D. CYLINDRICUM ...132 APPENDIX H - COLONY ABUNDANCES - D. DIVERGENS 133 APPENDIX I - CELL DENSITIES - D. CYLI NDRI CUM 134 APPENDIX J - CELL DENSITIES - D. DIVERGENS 135 APPENDIX K - ANALYSIS OF INTERSPECIFIC COLONY MORPHOLOGY DIFFERENCES 136 APPENDIX L - ANALYSIS OF MEASURED LORICA LENGTHS 138 APPENDIX M - ANALYSIS OF LORICA LENGTH ESTIMATES 139 APPENDIX N - ANALYSIS OF COLONY WIDTH 140 APPENDIX 0 - ANALYSIS OF COLONY LENGTH 142 APPENDIX P - COLONY SIZE DATA 144 APPENDIX Q - COLONY SIZE DIFFERENCES BETWEEN DEPTHS 146 APPENDIX R - OTHER COLONY VARIABLES 147 APPENDIX S - ZOOLANKTON ABUNDANCES 149 APPENDIX T - ANALYSIS FOR DIFFERENCES IN COLONY SIZE BETWEEN REPLICATE SAMPLES 169 APPENDIX U - ZOOPLANKTON GUT ANALYSES RESULTS 170 APPENDIX V - STATION II RESULTS 171 APPENDIX W - RESULTS OF WEIGHTED DATA ANALYSIS 172 vi L i s t of Tables I. Morphometry of Como Lake 17 II . Como Lake Chemistry 19 I I I . C e l l volumes ( x.m3) of D. cylindricum and D. divergens ; 47 IV. Colony variables - s t a t i s t i c s 55 V. Measured l o r i c a lengths of D. cylindricum and D.divergens 55 VI. Estimated l o r i c a lengths. ., ; 56 VII. Predominant zooplankton species occurring in Como Lake - January to A p r i l 1983 73 VIII. Abundances of single empty l o r i c a s and empty colonies (#/ml) 101 v i i L i s t of Figures 1. Preserved Colonies of Dinobryon 7 2. The location of Como Lake, B.C 20 3. Contour p r o f i l e of Como Lake 21 4. Dinobryon colony measurements 34 5. Isotherms (°C) 42 6. Maximum dail y temperatures of Como Lake area 43 7. Daily duration of bright sunshine Como Lake area 43 8. P r o f i l e s of the percent surface irradiance remaining per depth 44 9. Secchi disc p r o f i l e s 45 10. The weekly mean concentration of soluble reactive phosphate 46 11. Colony densities 50 12. C e l l densities 51 13. P r o f i l e s of colony densities 52 14. P r o f i l e s of c e l l d e n s i t i e s 53 15. Temporal variation in l o r i c a length estimates 58 16. Linear regression of colony width on colony size (#LPC). 59 17. Linear regression of colony length on colony size (#LPC) 60 18. Colony size frequency d i s t r i b u t i o n s 64 19. Overall temporal changes in the colony size 65 20. Temporal changes in colony size per depth 66 21. Contemporaneous changes in colony size and colony densities 67 22. Temporal variation in colony length and width 69 v i i i 23. Temporal variation in number of l o r i c a s per longest branch 70 24. Temporal variation in number of l o r i c a s and number of empty l o r i c a s per colony 71 25. Temporal variation in percentage of statospores per colony 72 26. Temporal d i s t r i b u t i o n of r o t i f e r species 75 27. Temporal d i s t r i b u t i o n of cladoceran species. 76 28. Temporal d i s t r i b u t i o n of copepod species 77 29. Zooplankton Gut Analysis Examples 95 30. D. cylindricum Colony Size Frequency Distributions ...96 31. D. divergens Colony Size Frequency Distributions 97 32. Combined Size Class Frequency Distributions ...98 33. Station II Results 100 ix Ac knowledgement F i r s t and foremost, I would l i k e to acknowledge Dr. Janet R. Stein for her generous f i n a n c i a l support, the use of her laboratory, extensive c o l l e c t i o n of books and reprints and her e d i t o r i a l and c r i t i c a l s k i l l s without which th i s Masters program would not have been what i t was. I would also l i k e to thank the members of my committee, including Dr. K. Cole for her help and encouragement from the beginning, Dr. Bob DeWreede for his friendship, because his door was always open and for his willingness to disscuss matters both large and small, and f i n a l l y Dr. B i l l N e i l l for the challange and for his timely advice. I would.also l i k e to thank numerous others who aided me including C. L. Dodgson for his rosey characture of ecology and ecologists, Rich Evens for the ecological/metaphysical discussions, Dr. S. Johnson for his timeless correspondance, Dr. Jack Maze for his help and poppycock, Rob Scagel for his s t a t i s t i c a l help and assertion that data should be explored and not exalted, and Mr. Laszlo Veto for his interminable advice. This thesis was supported in part by NESERC grant #1035 to Dr. Stein and by a U.B.C. Summer University Graduate Fellowship to the author of t h i s thesis. 1 I. INTRODUCTION 1. PHYTOPLANKTON COLONIES The term colony is somewhat vague, as i t i s used to describe a vast d i v e r s i t y of associations in the b i o l o g i c a l l i t e r a t u r e . This is p a r t i c u l a r l y true considering that monospecific associations frequently occur across most phyla and that these d i f f e r greatly in t h e i r degrees of integration, coordination and genotypic relatedness (Mackie 1963, Boardman et a l . 1973, Rosen 1979). More accurate terminology has been suggested (e.g., continuous modular s o c i e t i e s ; Rosen 1979) but, since the term colony i s used extensively in the phytoplankton l i t e r a t u r e , i t is therefore used in this thesis. More d e f i n i t i v e terms would be better applied in i n t e r p h y l e t i c comparisons than they would be here. As i t is used in the current phytoplankton l i t e r a t u r e , the term colony describes the physical association of individual phytoplankton c e l l s (Beklemeshev 1970, Boardman e_t a_l. 1973, Farmer 1980, Harlin et a l . 1982, Scagel et a l . 1982). These colonies are formed by the non-dissociation of the c e l l s following binary f i s s i o n either through the fusion of c e l l walls and c e l l wall processes or through th e i r retention in a common mucilaginous sheath (Round 1973, Reynolds 1984). Each colony i s therefore a single genetic entity comprising two or more modular units - i t s constituent c e l l s . In e f f e c t , the phytoplankton 2 colony is no more than an enlarged phytoplankton c e l l , segmented into numerous i d e n t i c a l units. Colony formation often occurs in phytoplankton species. Although estimates of the proportion of phytoplankton species that form colonies vary, i t i s generally agreed that they comprise a large percentage of the t o t a l (Smayda 1970, Lewis 1976, Round 1981). The c o l o n i a l habit is more common in freshwater lakes than in the marine habitat, occurring in more than 50% of limnetic phytoplankton species (Lewis 1976, Round 1981). Although colonies can be c l a s s i f i e d into a few basic types, the d e t a i l s of colony formation d i f f e r from species to species (F r i t s c h 1935, Round 1973, Sournia 1981). Phytoplankton colonies have diverse phylogenetic origins and as such are examples of convergent evolution (Fryxell 1978). The widespread occurrence of colonies, both taxonomically and in diverse aquatic habitats, attests to t h e i r success as a morphological strategy in phytoplankton. Yet t h i s raises the question, to what i s this success due? 2. EXPLANATIONS FOR COLONY FORMATION In spite of the prevalence of phytoplankton colonies, l i t t l e i s known for certain about their functional s i g n i f i c a n c e . Lewis (1976) argued that colony formation enables a single c e l l to reach sizes unattainable by c e l l enlargement alone. As the 3 size of a c e l l increases, i t s surface:volume r a t i o declines by a power of two thirds. Surface area is of paramount importance to such essential processes as nutrient uptake, l i g h t absorption and waste expulsion. The decrease in c e l l surface area r e l a t i v e to volume, as the demands of c e l l u l a r processes grow with increasing c e l l size, ultimately l i m i t s the maximum size of the c e l l (Lewis 1976, Karp 1979, Reynolds 1984). Colony formation allows a phytoplankton c e l l to e s s e n t i a l l y increase i t s size without encountering the r e s t r i c t i o n s of surface to volume ratios (Lewis 1976, Walsby & Reynolds 1980, Reynolds 1984). The circumvention of these constraints does not provide a s u f f i c i e n t explanation for colony formation in phytoplankton, for i t does not explain the advantages of increased si z e . Indeed, there are i n t r i n s i c disadvantages in the c o l o n i a l habit, including increased sinking rate (Smayda 1970, Walsby & Reynolds 1980, Reynolds 1984), the p o s s i b i l i t y of in t r a c l o n a l competition for nutrients (Hughes 1980) and reduced propulsive e f f i c i e n c y for motile phytoplankton (Sleigh & Blake 1977, Vogel 1983). There must therefore be compelling reasons to require an increase in size that balance or outweigh these l i a b i l i t i e s . There are two hypotheses that predominate in the l i t e r a t u r e which may account for the advantage of increased size in phytoplankton. The f i r s t of these argues that colony formation, p a r t i c u l a r l y in non-motile diatoms, increases the f r i c t i o n a l resistance that these phytoplankton have to the water around them (Smayda 1970, Walsby & Reynolds 1980). In e f f e c t , the f r i c t i o n a l resistance afforded by the arrangement of c e l l s in a 4 colony is greater than the sum of that accrued by the component c e l l s i n d i v i d u a l l y . This increased "form resistance" enhances the entrainment of the component c e l l s of a colony in turbulence and currents of the water column. Therefore c o l o n i a l c e l l s do not sink out of the epilimnion so quickly and are maintained longer in the euphotic zone than single c e l l s . They are s i m i l a r l y transported more often between nutrient patches than are individual c e l l s (Smayda 1970, Walsby & Reynolds 1980). Photoinhibition and l i g h t damage may also be minimized by the enhanced tumbling and rotational movements imparted to the colonies by currents. Such movements also may improve nutrient procurement by reducing boundary layers and micro-gradients around the c e l l s (Smayda 1970). The second prevalent hypothesis for the function of phytoplankton colonies argues that colony formation increases the size of a phytoplankter c e l l r e l a t i v e to i t s zooplankton grazers. Colonies therefore function as an anti-predator defence, rendering the phytoplankter too large to be handled or ingested by zooplankton. This hypothesis has pervaded the l i t e r a t u r e since the late 1800's (Schutt 1892, Munk & Riley 1952, Beklemeshev 1959, Lund 1965). It i s widely c i t e d today as a major explanation for the existence of phytoplankton colonies (Porter 1977, Kalff & Knoechel 1978, Morgan e_t a l . 1980, Moss 1980, Porter 1981, Sournia 1982, Reynolds 1984). Evidence for t h i s second hypothesis comes from a variety of sources. Indirect evidence i s taken from f i e l d observations in which large-celled or c o l o n i a l phytoplankton are either absent 5 from the guts of zooplankton, (Gliwicz 1969a, 1977, Cushing 1976, Nadin-Hurley & Duncan 1976, Moore 1979a, Ferguson e_t a l . 1982), or in which they predominate the phytoplankton community when zooplankton are numerous (Bailey-Watts 1974, 1978, Bailey-Watts & Kirka 1981, Nicholls et a l . 1980). Experimental manipulations of natural populations have provided more evidence to support this hypothesis (Hargrave & Geen 1970, Porter 1973, O'Brien & DeNoyelles 1974, Gliwicz 1975, Lynch & Shapiro 1981, Thompson et a_l. 1982), as have laboratory experiments (Beklemeshev 1959, Burns 1968, Webster & Peters 1978, Holm et a l . 1983). These studies suggest that c o l o n i a l phytoplankton are not grazed so e a s i l y as smaller, s i n g l e - c e l l e d species. Therefore, colonialism in phytoplankton is thought to be advantageous under conditions of intensive grazing pressure, when colonies do not suffer the same high mortality rates as the smaller, more vulnerable, individual c e l l s . 3. DINOBRYON 3.1 Occurrence The more than 25 species of the genus Dinobryon Erhrenberg (Ochromonadales, Chrysophyceae) are freshwater c o l o n i a l phytoplankton (Bourrelly 1981) which occur world-wide (Ahlstrom 1937, Bourrelly 1961, Hutchinson 1967, Moore 1978, Nygaard 1979, Cassie 1984). Although species have been observed to f l o u r i s h in l o t i c (Moore 1979c, Wehr 1979), and estuarine habitats 6 (Fritsch 1935, F.J.R. Taylor pers. comm.) as well as the hypolimnion of lakes (Fee 1976, Bloomfield 1980) - the genus is best known for the transient spring blooms of such common species as D. cylindricum Imhof and D. divergens Imhof in the euphotic zone of temperate lakes and ponds. The vernal appearance of phytoplankton assemblages dominated by these species is a remarkably persistent event in temperate lakes (Reynolds 1980). Every year, during the onset of thermal s t r a t i f i c a t i o n , under conditions of very low inorganic phosphorus concentrations, these assemblages replace the annual spring blooms of diatoms (Hutchinson 1967, Lehman 1976, Reynolds 1980, 1984, Round 1981). These spring pulses of Dinobryon are i n i t i a t e d from populations of resting spores (statospores) on the lake bottom. From each s i l i c i o u s statospore four amoeboid c e l l s germinate in response to the increasing insolation of spring (Pascher 1943, Sheath et al_. 1975). Each c e l l then generates two f l a g e l l a and synthesizes a predominantly c e l l u l o s i c receptacle or l o r i c a (Herth & Zugenmaier 1979), which can be c y l i n d r i c a l , conical or campanulate in shape (Fig. 1; Ahlstrom 1937, Huber-Pestalozzi 1941, Bourrelly 1981). The l o r i c a i s the result of the coordination of c e l l u l a r processes and complex c e l l movements which is under s t r i c t genetic control (Franke & Herth 1973). Lorica morphology i s species s p e c i f i c (Ahlstom 1937). Following d i v i s i o n of each c e l l , one of the resultant c e l l s moves to the l i p of the l o r i c a and, upon attaching i t s e l f there, proceeds to synthesize i t s own l o r i c a (Herth 1979). Repeated 7 Figure 1 - Preserved Colonies of Dinobryon. D. cylindricum A, D. divergens B and a closeup of D. cylindr icum c e l l s C - from Como Lake; Magnification 400X A & B, 1000X C. div i s i o n s such as this culminate in the formation of an arbourescent (dendroid) colony (Ahlstrom 1937, Kudo 1966), whose shape is ultimately determined by the number and morphology of the component l o r i c a s (Fig. 1). Colonies of Dinobryon migrate from the bottom of the lake 8 to the euphotic zone where the bulk of the population concentrates (Hutchinson 1967). Populations persist for r e l a t i v e l y short periods of one to four weeks, dominating the phytoplankton community only b r i e f l y before declining. The waning of these populations is t y p i c a l l y precipitous. Statospores are produced throughout the pulse and serve to i n i t i a t e subsequent blooms (Sheath et a l . 1975, Sandgren 1981, 1983). 3.2 Adaptations For Spring Appearances One explanation of the timing of Dinobryon spring blooms, postulated that high concentrations of inorganic phosphorus were toxic to the species, and they could not increase u n t i l the phosphorus levels were low (Pearsall 1932, Rodhe 1948). More recent research has undermined this hypothesis and proposed an alternative explanation more in l i n e with current knowledge of phytoplankton physiology (Tilman et al. 1982). Lehman (1976) demonstrated that D. cylindricum and D. divergens are very e f f i c i e n t at acquiring inorganic phosphorus at low ambient concentrations, in addition to having r e l a t i v e l y low maximum growth rates. (The half saturation constants for each species respectively were: 0.72 & 0.42 Mmol/L). This would enable these species to dominate the phytoplankton community when inorganic phosphorus levels are too low for other species, such as the vernal diatoms, which have higher overa l l growth rates but less e f f i c i e n t uptake kinetics (Lehman 1976). E f f i c i e n t phosphorus acquisition i s just one facet of their 9 biology that suggests that spring blooming species of Dinobryon are suited to the conditions of that time of year. Temperature tolerances are broad, encompassing the range of temperatures expected in spring (Hutchinson 1967, Munch 1972, Lehman 1976). Statospore formation may be sexually or asexually induced and i s i n i t i a t e d by number of internal and external cues such that they are produced throughout a population pulse (Sandgren 1981). The variable induction of resting spores in Dinobryon is not common in other freshwater phytoplankton species. It ensures that statospores w i l l be available for subsequent blooms, regardless of the fate of the present population, at a time when the factors determining the growth and decline of phytoplankton populations are rapidly changing. variable induction (Sandgren 1978, 1981, 1983). Two questions may be posed by the apparent s u i t a b i l i t y of Dinobryon species to spring conditions. F i r s t , what advantages does the formation of colonies confer at this time of year? Second, what factors ultimately contribute to the sudden and rapid decline in their populations ? 3.3 The Function Of Colonies In Dinobryon Since Dinobryon colonies are motile, they are able to maintain a constant depth and to quickly return to t h i s depth following their displacement by a temporary disturbance of the water column (Sheath et a l . 1975, Fee 1976, Bloomfield 1980, Corbet et a l . 1980, Frempong 1981). Additionally, the dendroid 1 0 c o l o n i a l shape and the lack of coordination of the constituent c e l l s imparts an o v e r a l l tumbling movement to the colony as i t moves along (pers. obs.). These facts attest to e f f e c t i v e self mobility. They also render the f i r s t hypothesis regarding the functional significance of colony formation untenable, since none of the postulated advantages of c e l l s joined in a colony, v i s - a - v i s entrainment in lake currents, would apply (Smayda 1970, Reynolds 1984). Therefore, only the second of the two hypotheses on colony formation is worth considering when seeking an explanation for colony formation in Dinobryon. In regards to t h i s second hypothesis, Munch (1972) speculated that colony size could be extremely important in determining the v u l n e r a b i l i t y of Dinobryon populations to grazing. Her q u a l i t a t i v e observations suggested that the smaller colonies of D. divergens declined in number more rapidly, and were found in proportionally greater numbers in the guts of zooplankton, than were the larger sized colonies of D. cylindricum. S i m i l a r i l y Fee e_t §_1. (1977) and Fee (1978) argued that the dense hypolimnetic populations of co l o n i a l chrysophytes, including Dinobryon, developed and persisted in part due to the minimization of grazing losses that colonies afforded. The vernal species of Dinobryon are therefore e s p e c i a l l y suitable subjects with which to investigate the hypothesis that colony formation increases the size of the phytoplankter r e l a t i v e to zooplankton grazers and thereby reduces losses due to grazing. 11 3.4 Dinobryon Population Declines There i s at present no satisfactory explanation for the precipitous declines in vernal Dinobryon populations. Undoubtedly the causal factors are complex involving the summation of both growth and loss processes. Pulses of Dinobryon populations are very b r i e f , with rapid increases and even more rapid declines. This is indicative not only of large imbalances between growth and loss rates but also of the very rapid t r a n s i t i o n from the predominance of growth processes to that of loss processes (Kalff & Knoechel 1978). According to the observations of some researchers, whereas physico/chemical factors determine which phytoplankton species can occur at any given time, loss processes, such as grazing, can determine their densities and therefore their dominance in a phytoplankton assemblage (Kalff & Knoechel- 1978, Lund & Reynolds 1982, Lynch & Shapiro 1981, Reynolds et a l . 1982). Therefore i t may be informative to consider which of the loss factors, acting alone or in unison, are the causal factors behind the decline of Dinobryon populations. The sharp and transitory nature of Dinobryon spring pulses indictates that such factors act intensively and dec i s i v e l y to counteract the rapid growth of the populations, or to cause a rapid decline when population growth rates slow. The consistency of Dinobryon's rapid appearance and decline each spring requires that such loss factors reoccur every year. Blooms of Dinobryon occur at a time when the zooplankton community i s expanding in both biomass and species number 1 2 (Gliwicz 1977, Fogg 1980, Pace & Orcutt 1981). The increase in the size of the zooplankton community, coupled with the r i s e in spring temperatures, could result in p o t e n t i a l l y greater grazing pressures on the populations as spring progresses. The p o s s i b i l i t y therefore e x i s t s that the rapid spring declines in Dinobryon populations are the result of increasing losses through grazing. That the decline of Dinobryon populations may be due to grazers has already been c i t e d (Munch 1972). Additionally, Lehman (1976) in his study on the ecology of vernal Dinobryon species proposed that grazing could account for their population declines when physico-chemical factors could not be implicated. That Dinobryon is grazed, and at times grazed heavily, is evident in a number of studies involving zooplankton gut analysis (Tappa 1965, Munch 1972, Moore 1979a, 1979b, Kryuchkova & Rybak 1980) as well as laboratory experiments (Munch 1972, Sandgren 1978). Data therefore exist in the l i t e r a t u r e to support the idea that grazing may be a major loss process which causes the population declines. In summation then, there i s evidence to suggest that colony formation in vernal species of Dinobryon may function to deter or prevent grazing. However, there is also evidence suggesting that Dinobryon colonies are grazed and that the decline of their populations at that time of year could be due to the expanding zooplankton community. As such, these two l i n e s of evidence are p o t e n t i a l l y paradoxical, for how can grazing be the underlying 1 3 cause of Dinobryon population declines i f the colonies of Dinobryon deter grazers? 4. HYPOTHESES . 4.1 Hypotheses Formulation Scattered reports in the l i t e r a t u r e suggest a f i r s t possible solution to t h i s paradox. In 1943 Braun noted that the number of c e l l s per colony of D. bavaricum Imhof were the greatest at peak population den s i t i e s . Munch (1972) observed that D. divergens and D. cylindricum seemed, l i k e other chrysophytes, to have the largest colonies during the onset of population growth. Thereafter colony size declined, with that of D. divergens declining more rapidly than that of D. cylindricum. Other authors have observed variable colony sizes in these and other species of Dinobryon (Ahlstrom 1937, Braun 1943, Franke & Herth 1973, Sheath & Munawar 1974, Herth & Zugenmaier 1979). Although these observations were q u a l i t a t i v e , i t i s apparent that Dinobryon colony size varies and may possibly decline in the course of a bloom. It also has been demonstrated that there is variation in l o r i c a length within colonies (Lemmermann 1900, Ahlstrom 1937, Braun 1943), within the same population (Ahlstrom 1937) and seasonally (Lemmermann 1910, Pascher 1913, H i l l i a r d 1968). Lorica length has also been inversely correlated with temperature ( H i l l i a r d 1968). 1 4 The number of l o r i c a s per colony and the lengths of l o r i c a s both contribute to the overall size of a colony. As a spring time bloom of Dinobryon progresses, a decline in the number and/or size of l o r i c a s would result in smaller colonies. I f , by virtue of their size, colonies function as a defence against grazing, then with a decreasing mean colony size the Dinobryon population would become increasingly vulnerable to a broader spectrum of zooplankton grazers. Progressively greater losses through grazing would occur as a r e s u l t , and i f this were to continue, Dinobryon numbers would decline. This scenario provides a solution to the paradox outlined above. It also provides the rationale for the f i r s t hypothesis that, in part, served as the focus for this thesis; (IA) Dinobryon colonies exhibit temporal variation in size as a function of l o r i c a length and or number. (IB) The c o l o n i a l habit of Dinobryon functions to deter or prevent potential grazers, the effectiveness of which is determined by i t s o v e r a l l s i z e . There i s , however, an alternative solution to the paradox. The maximum size of phytoplankton that can be eaten by a zooplankter depends upon the zooplankton's size (Burns 1968) and i t s a b i l i t y to capture and ingest that size of phytoplankton (Gliwicz 1974, Allen 1976, Morgan et a l . 1980). The grazing pressure exerted by the zooplankton community on any size class of phytoplankton depends upon i t s constituent species and on 1 5 their abundances (Haney 1973). The increase in the zooplankton biomass and species number in spring constitutes changes in the overall grazing pressure on d i f f e r e n t sized phytoplankton. Even without postulating a decline in the mean colony size, grazing can play an important role in Dinobryon population declines. An increase in a zooplankton species capable of handling and ingesting the available size of colonies would also result in increased grazing pressure. These considerations underlie a second hypothesis that also guided the research of t h i s thesis, namely; (2) The temporal d i s t r i b u t i o n of those zooplankton species capable of ingesting the available size range of Dinobryon colonies is an important factor in determining the occurrence and abundance of Dinobryon populations. 4.2 Limitations Of The Hypotheses The above hypotheses are unavoidably broad in scope. Their incisiveness was blunted by the lack of quantitative information on the essential variables. There are no precise data on the s p a t i a l and temporal variation in Dinobryon colony size. In fact most data on Dinobryon abundances have previously been expressed as c e l l numbers (Hutchinson 1967, Sheath et a l . 1975, Sandgren 1978). Without such background information, no reasonable assessment could be rendered on the potential for Dinobryon colonies to deter grazers. S i m i l a r l y there has been no documentation of the contemporaneous d i s t r i b u t i o n of the 16 zooplankton community and Dinobryon pulses. These data were required before any precise hypotheses could be formulated regarding the grazing pressures facing Dinobryon populations. This lack of background data i s not surprising considering that t r a d i t i o n a l l y phytoplankton research has concentrated on those factors influencing growth and ignored loss processes (Kalff & Knoechel 1978, Reynolds 1984). U n t i l recently few studies have addressed hypotheses such as these. No studies have dealt with loss processes in Dinobryon populations. The absence of this basic information not only constrained the nature of the hypotheses but also the research that addressed them. To f i l l in these gaps of knowledge adequately required a considerable a l l o c a t i o n of time. As such, th i s study is largely f i e l d based and descriptive. It i s primarily concerned with d e t a i l i n g the temporal/spatial patterns • of variation in Dinobryon colony size and populations, the concommitant zooplankton community dynamics, and the p o s s i b i l i t i e s of interactions between them. Given the descriptive nature of this study, and the inherent l i m i t a t i o n s of i t s explanatory power, t h i s thesis ultimately serves to delimit the boundaries of the variables involved and to generate a new, more precise hypothesis consistent with the r e s u l t s . In short, t h i s thesis is an extensive background study for future research on the potential that phytoplankton colonies have in general, and that Dinobryon colonies have in p a r t i c u l a r , to function as anti-predator defences. II. MATERIALS AND METHODS 1. FIELD SITE Como Lake was the f i e l d s i t e for this study. It is situated in Como Lake park, surrounded by r e s i d e n t i a l houses, in the c i t y of Coquitlam about 20 km east of Vancouver, B r i t i s h Columbia (49° 15' 40"N: 122° 51' 25"E; Fig. 2). The lake and park are used extensively by the lo c a l residents for recreational purposes such as walking, jogging, and fishing for the f i s h that are stocked in the lake by the B.C. Ministry of Recreation and Conservation. This lake was chosen because a previous q u a l i t a t i v e study had documented the presence of some common Dinobryon species (Donaldson 1981). Como Lake can be characterized as a small, shallow, dystrophic lake. The physical c h a r a c t e r i s t i c s are l i s t e d in Table I. Data for t h i s table were obtained from the f i l e s of , 355m 4.7 ha . 976m *Shore Line Developement... . 1 .28 •Volume (Total) , 80,215 cu .m (0 - 1.5m) . 51,983 cu ,m . 21,509 cu m . 6,723 cu .m , 122m Table I - Morphometry of Como Lake. * Designates derived values. See text for explanation. 18 the Fisheries Research Group, Fish and W i l d l i f e Branch; B r i t i s h Columbia Ministry of Recreation and Conservation, located on the UBC campus. Values in this table that were subsequently calculated from the o r i g i n a l data are indicated. Estimates of the volumes of lake strata were made using a graphics tablet, and associated software, on an Apple 11+® computer, along with a depth contour map obtained from the same source (Fig. 3). Small ephemeral streams drain into the lake, from the gently sloping terrain of the surrounding park. Few trees grow in t h i s park and so the lake is completely open to the elements. There is only one main outlet, an unnamed stream at the south end of the lake, which ultimately drains into the Fraser River (Fig. 3). The persistent brown colour of the lake waters is c h a r a c t e r i s t i c of dystrophic lakes that are supplied by r e l a t i v e l y large amounts of allochthonous organic matter (Wetzel 1975). In this instance, the humic substances are derived primarily from wood chips and debris ( l e f t from past logging operations in the area) which are an integral part of both the surrounding s o i l s and the lake bottom. As a consequence the lake transparency i s reduced, ranging, during th i s study, from Secchi disc readings of 1.1 m in the summer to 2.6 m in the winter months. Some of the chemical aspects of Como Lake, derived from surface samples taken over a period of two and one half years (1979-1982; Contant 1984), are l i s t e d in Table I I . The Vancouver Greater Regional D i s t r i c t in i t s 1979 O f f i c i a l Regional Plan for the Lower Mainland has designated 19 PH 5.6-7.2 18-33 mg/L 8.3-11 mg/L Nitrate 8-820 mg/L 8.3-11.8 mg/L Soluble Reactive Phosphate. 0-15 yug/L Table II - Como Lake Chemistry (Contant 1984). Como Lake as a " s i g n i f i c a n t b i o l o g i c a l area" (G.V.R.D. 1979). This designation was applied to the lake for i t s "dive r s i t y of habitats and w i l d l i f e " . At the north end of the lake there is a dense stand of Typhus l a t i f o l i a L. ( c a t t a i l ) which provides nesting s i t e s for water fowl such as Anas plaryrhynchnos L. (mallard) and Fulica americana Gmelin (cout). Brasenia serberi Schreb. (water shield) covers most of the lake during the summer and is used as cover by both indiginous f i s h Ictalurus nebulosus LeSueur (brown bullhead) and the f i s h stocked in the lake (Salmo gairdneri Richardson - rainbow tr o u t ) . The lake is also used by migratory birds throughout the year including Branta canadensis L. (Canada goose) and Mergus  merganser L. (common merganser). 20 Figure 2 - The location of Como Lake, B.C. 21 Figure 3 - Contour p r o f i l e of Como Lake. Triangles with enclosed Roman numerals locate the f i r s t and second stations. 22 2. SAMPLING 2.1 General Considerations Como Lake was sampled at weekly intervals from January to A p r i l .1983, between 0630 and 1200h. The second week of March was missed during that 17 week period. The sampling was c a r r i e d out from a small dinghy at two stations approximately 300 meters apart in the middle of the lake (Fig. 3). These two stations were located each week by triangulation with landmarks on the shore. Samples were collected using a PAR® e l e c t r i c bilge pump, powered by a 12 volt car battery, with a pumping capacity of 37.5 L/min. Variable sized samples can be obtained quickly with a pump and therefore both . the r e l a t i v e l y sparse zooplankton community and the more abundant phytoplankters can be sampled using this method. It also minimizes the v a r i a b l i t y between zooplankton samples and the e f f e c t s of zooplankton escape behavior ( N e i l l 1981). Samples were drawn from the lake through 25 mm (I.D.) clear v i n y l tubing marked at 0.5 m inter v a l s from the intake mouth to determine the sampling depth. Since the v i n y l tubing s t i f f e n e d up considerably at temperatures below 7°C, a 2.2 kg weight was attached at the inflow end, to stretch the tubing. This weight was also used when the intake tubing became more f l e x i b l e in warmer temperatures. Throughout sampling, the dinghy was maintained on station -and stationary by the use of an anchor and l i b e r a l use of the oars. 23 The p o s s i b i l i t y of turbulent mixing between depths was minimized by the following precautions. The inflow and outflow tubing were located on opposite sides of the boat. Pumping was re s t r i c t e d only to those times when samples were being taken. The force of the pump's discharge was dissipated by passing i t over one of the oar blades (when the pump was being cleared between depths), into the 3 L sampling container, or through the plankton net as described below in Section 2.3-Biological Factors. 2.2 Physico-chemical Factors Temperature, irradiance, oxygen concentrations, and Secchi disc readings were taken every week at each station. Temperature readings were made of the a i r and at 0.5m intervals in the lake using a model YSI® Oxygen meter. The oxygen concentrations were determined with the same instrument, but due to instrument malfunctions these determinations were made infrequently and f i n a l l y terminated after the last week of February. A Li-Cor® (model LI-185A) 27r Photometer was used to take irradiance readings 1 m above the lake, 50 mm below the lake surface and at half metre inter v a l s to the lake bottom. The irradiance meter was lowered to depth and maintained there at right angles to the lake surface by the use of an improvised lowering frame. A l l irradiance readings were made facing the sun. Secchi disc readings, on the other hand, were made from the side of the boat opposite the sun. Data on solar irradiance, maximum and mean dail y temperatures were taken from 24 the Environment Canada, Atmospheric and Environment Services data, c o l l e c t e d at Vancouver International Airport (E.C. -A.E.S. 1983). These data were gathered only 25km from the study s i t e . As such they are generally representative of the meteorological conditions at the lake (Wetzel & Likens 1979), although the influence of mountains to the north of the lake should be considered. For the determination of soluble reactive phosphate levels in the lake at the time of sampling, one 1.5 L sample was colle c t e d at each depth of each station. To eliminate any extraneous phosphate contamination from the sample bottles a number of precautions were taken. Each sample bottle was o r i g i n a l l y rinsed in a 10% solution of HC1 followed, by numerous rinses in d i s t i l l e d water. Each week, prior to sampling the bottles were washed in Decon® (Decon Laboratories Ltd; BDH Chemicals, Toronto) and rinsed thoroughly in d i s t i l l e d water. These precautions were tested with s i m i l a r l y washed bottles, f i l l e d only with d i s t i l l e d water, analyzed as described below. No detectable phosphate was found in these test bottles. F i n a l l y , before being f i l l e d with water from a s p e c i f i c depth, each bottle was rinsed twice with the water from that depth. Samples were transported on ice to the laboratory where they were f i l t e r e d through p r e - s t e r i l i z e d Whatman GF/C® glass fiber f i l t e r s within 6h of c o l l e c t i o n . Each f i l t e r used was preconditioned by f i r s t f i l t e r i n g and discarding 250 ml of the sample to be analyzed, to saturate that f i l t e r with phosphate. The analysis of soluble reactive phosphate followed the 25 procedure of Wetzel and Likens ( 1 9 7 9 ) . Preliminary tests determined that the soluble reactive phosphate levels were less than 10/u g/L. Therefore isobutanol ( 2-methy 1-propan- 1 -ol) was used to extract the blue colour complex (Alternative A in Wetzel and Likens 1979). Standards of 0, 1 , 5, 10 vq/L were run for each week's analysis. A l l colourimetric determinations were made using a 10 mm test tube cuvette on a Bausch & Lomb® Spectronic 21 spectrophotometer. For consistency the same cuvettes were used for the same samples and standards each week. 2.3 Bi o l o g i c a l Factors Water for the phytoplankton samples was pumped from the desired depth into a 3L p l a s t i c container with holes punched into i t at the 2L l e v e l . The container was f i l l e d and allowed to overflow for at least 5 seconds, while mixing the sample thoroughly with the outflow tubing as i t f i l l e d the container. A 200 ml subsample was then taken by plunging a measured p l a s t i c jar into t h i s container (Dr. W.E. N e i l l pers. comm., Willen & Willen 1979). Two phytoplankton samples were taken per depth and were preserved in a 4% solution of formalin in Lugol's preservative (Throndsen 1978). In the laboratory the samples were gently concentrated by reverse flow f i l t r a t i o n (Dodson & Thomas 1964, 1978). The concentrate was then transferred after two washings of d i s t i l l e d water to 24 ml s c i n t i l a t i o n v i a l s and stored in the dark. The stored samples were p e r i o d i c a l l y replenished with preservative (ca. 2 mo). In retrospect, the use of the s c i n t i l l a t i o n v i a l s 26 should have been avoided as the cap l i n e r coating readily oxidized the preservative, necessitating frequent replenishment. To test for any effect that the pump had on the colony size of either species of Dinobryon, five samples were taken from 0.75M at station II on 17 March. Three of these samples were taken by hand and two by the pump. The colonies of these samples were measured as described in 3.3. The data were analyzed for s i g n i f i c a n t differences among samples in the numbers of l o r i c a s per colony (#LPC), using single factor ANOVA (see II.4 S t a t i s t i c a l Considerations). There were no si g n i f i c a n t differences among a l l five samples (App. A). Therefore, the action of the sampling pump had no discernable effect on colony si z e . To sample the zooplankton, two samples of 37.5 L from each depth were pumped through a 75 Mm plankton net. The f i l t r a t e from each was drained into a 120 ml jar and the net was rinsed with tap water numerous times into the same j a r . The sample was preserved with the 4% formalin solution in Lugol's. These samples were subsequently allowed to s e t t l e in the laboratory for at least 24 h (Wetzel and Likens 1979) before the supernatant water was siphoned off and the sample stored (Sukhanova 1978). 27 3. PLANKTON ENUMERATION AND ANALYSIS 3.1 Species I d e n t i f i c a t i o n The sources that were used to ide n t i f y both phytoplankton and zooplankton are l i s t e d in App. B. 3.2 Phytoplankton 3.2.1 Samples Analyzed Only Station I phytoplankton samples were i n i t i a l l y analyzed. The enumeration of each sample, and the measurement of the colonies i t contained, required from 3 to 6 h to complete. Analysis of the entire body of samples would have entailed a prohi b i t i v e amount of time. Station II samples were therefore set aside for future analysis and for the checking of the results and hypotheses produced by the f i r s t half of the samples. 3.2.2 Phytoplankton Counts Dinobryon biomass determinations were made through the enumeration of an aliquot from each f i e l d sample. The biovolume of each of the p r i n c i p a l species was estimated by determining the c e l l u l a r volumes of randomly chosen colonies, in aliquots of Station I - 1 m samples, at the beginning of March and A p r i l . The volume of each c e l l was estimated from direct measurements of the two p r i n c i p l e dimensions, at 500X magnification on a 28 Leitz Dialux® compound microscope (Willen 1976). These measurements were made with a ca l i b r a t e d occular micrometer, to the nearest ocular unit (1 . 9yum) . For the enumeration, stored phytoplankton samples were f i r s t d i l uted in 50 ml centrifuge tubes to 50 or 100 ml, depending on the densities of Dinobryon present (Lund e_t a l . 1958, Wetzel & Likens 1979). The tubes were gently inverted numerous times to randomize the sample. A 10 ml aliquot was immediately poured into a sedimentation chamber 3 cm in height and was l e f t to s e t t l e over night (Nauwerk 1963, Hasle 1978a). The entire aliquot was subsequently enumerated at 80X magnification on a Zeiss® inverted microscope. The unit of enumeration was the entire Dinobryon colony (Lund e_t a_l. 1958, Smayda 1978). 3.2.3 Limitations Of The Analysis Recommended multistage sampling and enumeration methods for plankton are predicated on the assumption that each subsampling stage, from the o r i g i n a l f i e l d sample to the f i n a l aliquot, i s a random sample of the stage previous to i t . (Lund et a l . 1958, Wetzel & Likens 1979, Venrick 1978a,b). Unfortunately, even when the samples are well-mixed t h i s assumption i s not always met. In fact, within a mixed sample, d i f f e r e n t plankton species are d i s t r i b u t e d variously and not in a l l cases are these d i s t r i b u t i o n s random (Ricker 1937, L i t t l e f o r d et a l . 1940, S e r f l i n g 1949, Holmes & Widrig 1956, Kutkuhn 1958, Lund et a l . 1958). A single species can be d i s t r i b u t e d randomly sometimes, 29 but not at other times, within a sample (Lund e_t a_l. 1958). Furthermore, as the abundance of a species increases, nonrandom di s t r i b u t i o n s become increasingly frequent in samples (Frontier 1972, Rassoulzadegan & Gostan 1976). If i t is to be applied at a l l , the assumption of randomness must be tested in a l l stages of subsampling. This is not feasible, for i t would e n t a i l a p r o h i b i t i v e l y large amount of time and e f f o r t . Besides, admonishments by authors to check the assumption of randomness are rarely accompanied by alternatives, should this assumption prove i n v a l i d (Lund et a_l. 1958, Vollenweider 1974, Hasle 1978b, Wetzel & Likens 1979, Sakshaug 1980) . The application of other theoretical d i s t r i b u t i o n s i s a p o s s i b i l i t y where the assumption of randomness is not.met. Generally their v a l i d i t y has not been established in the description of plankton sample d i s t r i b u t i o n s , as they have been in the s p a t i a l and temporal d i s t r i b u t i o n s of plankton in the f i e l d (Venrick I978a,b). When the assumption of randomness i s not met, the d i s t r i b u t i o n of plankton in a sample i s usually contageous (Holmes & Widrig 1956). Therefore the application of the negative binomial d i s t r i b u t i o n may seem warranted. However, i t s usage has been seriously questioned, with the s t i p u l a t i o n that when a plankton sample i s not randomly distributed, a precise estimate of plankton abundance can only be obtained by counting the entire sample (Holmes & Widrig 1956). Moreover, should i t be possible to f i t a suitable d i s t r i b u t i o n to the plankton sample, i t would be f a l l a c i o u s to extend t h i s 30 d i s t r i b u t i o n to other samples or even to other data sets. In ef f e c t , each new sample would be another sp e c i a l case. One is faced with an intractable problem i f a precise estimate of the abundance of plankton in a sample is sought. Visual plankton counts are s t i l l unsurpassed as a method for estimating the phytoplankton biomass (Sakshaug 1980, Butterwick et a l . 1982). Yet in the case of large numbers of samples, or i f time is limited, the enumeration of entire samples is precluded. The alternative, that of enumerating one subsample, is based on the assumption that this subsample i s randomly drawn from the sample. This assumption can not always be met. Therefore the accuracy of the resultant biomass estimates can not be assessed. Possible approaches to this problem include: enumerating entire samples; determining a crude estimate of the frequency d i s t r i b u t i o n of plankton in aliquots, based on the analysis of a limited number of a l l samples taken; or ignoring the problem. I chose the l a s t a l t e r n a t i v e . Other a l t e r n a t i v e s e n t a i l a greater cost in time and e f f o r t or have dubious merit. Further, sampling, p a r t i c u l a r l y in the f i e l d , i s concerned with estimating rather coarse changes in the plankton populations and not distinguishing between fine-scaled v a r i a t i o n s in abundances (Lund et a_l. 1958). Considering t h i s f a c t , i t i s well to assume that during the enumeration, the plankton counted in aliquots are randomly chosen from the o r i g i n a l f i e l d samples and to use the Poisson d i s t r i b u t i o n to calculate the accuracy of these plankton counts. This not only saves considerable time 31 and conforms to currently accepted methodology, but also the calculated accuracy of the plankton count is s u f f i c i e n t for the purposes at hand. In doing so, i t should be realized that these estimates of the accuracy of the counts, obtained through the application of the Poisson d i s t r i b u t i o n , are, by and large, an underestimate (Holmes & Widrig 1956). 3.2.4 Colonial Phytoplankton Enumeration In addition to a persistent problem of the nonrandom d i s t r i b u t i o n of c o l o n i a l phytoplankton in samples (Holmes & Widrig 1956, Hasle 1968), there exists the d i f f i c u l t y that abundances of phytoplankton are usually expressed in terms of c e l l s per unit volume. It i s only v a l i d to count entire colonies when enumerating c o l o n i a l phytoplankton. Counting single c e l l s when they are joined together in a colony v i o l a t e s the c r i t e r i o n of independence required in the application of the Poisson d i s t r i b u t i o n to plankton counts (Lund et a l . 1958, Venrick 1978a). Considering the foregoing discussion, adherence to this c r i t e r i o n may seem misplaced since a random d i s t r i b u t i o n in even well mixed samples can never be assumed. However, the deliberate v i o l a t i o n of the cri t e r o n would invalidate the use of the Poisson with certainty. If the d i s t r i b u t i o n i s to be used, even with t a c i t knowledge of the f a u l t s of doing so, then i t s c r i t e r i a should be met as far as possible. To quantify c o l o n i a l phytoplankton in terms of the number of c e l l s per unit volume, two estimates are therefore required: 32 the number of colonies per unit volume and the mean number of c e l l s per colony. If the mean number of c e l l s per colony is constant, or "does not vary widely" then the number of c e l l s per unit volume can be obtained from the product of these two estimates (Lund et al_. 1958). Al t e r n a t i v e l y , their product and the combination of their respective standard errors can be calculated. But this is only v a l i d where the variance of each " i s small r e l a t i v e to" their respective values squared (Yates 1960). Unfortunately the two quotes c i t e d here are neither explained, nor are they quantified. A t h i r d p o s s i b i l i t y i s to f i t a t h e o r e t i c a l frequency d i s t r i b u t i o n to both the mean number of c e l l s per colony and the number of colonies per unit volume. The product of these two frequency d i s t r i b u t i o n s would be a t h i r d frequency d i s t r i b u t i o n - the number of c e l l s per unit volume (Gilbert 1942). This approach i s frustrated by the p o s s i b i l i t y of correlations between the two variables and by the unlikelihood of finding a single t h e r o r e t i c a l d i s t r i b u t i o n which approximates the size d i s t r i b u t i o n of colonies (Gilbert 1942). Add to t h i s l a s t reason the fact that the d i s t r i b u t i o n of colonies in samples i s not adequately described by any known d i s t r i b u t i o n and the whole exercise becomes f u t i l e (Gilbert 1942, Venrick 1978b; see Discussion; 3.2.2). An attempt was i n i t i a l l y made to apply the second c a l c u l a t i o n to the data, but without success. The resultant combined standard errors were so large as to be impractical. The only remaining alternative was to multiply the estimated 33 number of colonies per m i l l i l i t r e (with i t s standard error) by the mean number of c e l l s per colony. As outlined above, the calculated accuracy of these counts is of dubious value. Yet i t has been demonstrated that the error contributed by converting from colony counts to c e l l densities i s small r e l a t i v e to the v a r i a b i l i t y inherent in the phytoplankton populations themselves (Lund et a_l 1958). Thus th i s last alternative was chosen as the best conversion from colonies to c e l l s per unit volume. 3.3 Colony Measurements After counting, 31 colonies of each species were randomly located (Guillard 1973) in the same chamber and measured, providing they had at least one l o r i c a which contained a c e l l (Fig. 4). The following variables were determined for each colony: colony length - the greatest a x i a l linear distance (GALD); colony width - the next greatest dimension at right angles to the colony length; the number of l o r i c a per colony (#LPC); the number of those l o r i c a s that were empty; the number of l o r i c a s in the longest linear branch; and the number of statospores per colony. Measurements were made on the inverted microscope, at 321.5X magnification, with a c a l l i b r a t e d ocular micrometer. A l l measurements were made to the nearest ocular unit (2.9jLtm, in this instance). 34 <—w—> 1 7 L o r i c a s per C o l o n y 3 Empty L o r i c a s 5 L o r i c a s per Longes t B ranch 1 S t a t o s p o r e Figure 4 - An example Dinobryon colony measurements. L = colony length; W = colony width. 3.3.1 Sample Size Of Colony Measurements The selection of sample size for measuring colonies was based on preliminary tests done on samples from weeks 1 and 2 of February and week 3 in March. These tests involved f i r s t the generation of performance curves of cumulative sample size against the means of three colony variables - t o t a l length, t o t a l width and number of l o r i c a (Brower & Zar 1977) and, second, the calc u l a t i o n of the optimum sample size to obtain a standard deviation within 20% of these means ( E l l i o t t 1977). It was so determined that the variable means s t a b i l i z e d at a sample size of 15 colonies and that a 20% standard deviation about the means could be expected for sample sizes between 20 and 45 35 colonies (depending on the inherent v a r i a b i l i t y of colonies in a sample). Consequently a sample size of 31 was selected knowing that the resultant variable means and variances were representative of the sample and because i t is considered to be a s t a t i s t i c a l l y "large" sample such that parametric s t a t i s t i c s could be applied to i t s analysis (Caulcott 1973, E l l i o t t 1977). When one aliquot per sample proved to be i n s u f f i c i e n t to meet t h i s sample size, more than one aliquot were scanned u n t i l 31 colonies were measured, or the entire sample was exhausted. 3.3.2 Colony Size Estimate Since the size of colonies is an int e g r a l part of thi s thesis, consideration was given to finding the best possible measurement. Estimates of colony size based solely on the t o t a l length of the colony ignore the contributions made by the t o t a l width. The r a t i o of these two variables is neither an accurate estimate, nor does i t provide insight into the relationship between them (Sokal & Rolf 1969). Calculation of colony volume, l i k e that of c e l l volume (Willen 1976), must assume that colonies have regular geometric shapes and that two dimensional measurements, ( i . e . colony length and width), can be translated into volumes through geometric formulae. Yet, the shape of Dinobryon colonies changes i r r e g u l a r l y with increasing numbers of l o r i c a s and depends upon the pattern of successive c e l l d i v i s i o n s . This precludes the use of a single formula or set of geometric shapes to describe the shape and therefore the size of Dinobryon colonies. Also, the orientation of a colony on the 36 bottom of the s e t t l i n g chamber determines what the measurement of width w i l l be. Colonies that have settled with their greatest width orientated at right angles to the chamber bottom, w i l l have both their width and volume underestimated. An estimate of colony size based on the numbers of l o r i c a s per colony (#LPC) is a better estimate than the preceeding techniques. The size and shape of a colony i s primarily determined by the l o r i c a s , being two to twelve times the length of their c e l l s (Ahlstrom 1937). Other variables are c e r t a i n l y involved in determining colony size and shape, such as the species s p e c i f i c l o r i c a morphology and to some extent the pattern of l o r i c a branching. But the degree to which these variables contribute to the colony size i s a function of the #LPC. Their contributions to colony size are also more d i f f i c u l t to estimate. Therefore, the #LPC was chosen as the best estimate of colony s i z e . Since the l o r i c a lengths of some Dinobryon species (e.g. D. suec icum var longi spina Lemmermann and D. Borgei Lemmermann; H i l l i a r d 1968) have been shown to change with temperature ( H i l l i a r d 1968), estimates of l o r i c a length are desirable i f colonies are being compared over an extended period of time. Because l o r i c a morphology i s species s p e c i f i c (Ahlstrom 1937), possible contributions of d i f f e r e n t l o r i c a morphologies to colony size should be investigated when i n t e r s p e c i f i c comparisons are made. The l o r i c a lengths of both species were estimated in two ways. F i r s t , colonies from the beginning of March and the 3 7 beginning of A p r i l were randomly chosen from aliquots of 1 m phytoplankton samples of Station I. Their l o r i c a s were measured d i r e c t l y at 500X magnification to the nearest calib r a t e d ocular unit (1.9*011, in this instance), on the inverted microscope. The resultant data were tested for s i g n i f i c a n t differences between dates and between species, each through single factor ANOVA. The second method involved estimating l o r i c a lengths by dividing the length of the longest branch (= colony length) by the number of l o r i c a s in that branch (See Fig . 4 ) . The quotient of these two variables underestimates the true l o r i c a length because each l o r i c a in a branch i s p a r t i a l l y contained within the previous l o r i c a (Fig. 1). Assuming that the proportion of the l o r i c a contained i s r e l a t i v e l y constant, changes in the lengths of l o r i c a s , or i n t e r s p e c i f i c differences are manifested using t h i s estimate. These estimates were examined for si g n i f i c a n t differences, both within and between species, using univariate oneway ANOVA. 3 . 4 Zooplankton Two methods of zooplankton enumeration were used. In the f i r s t , three 1 ml aliquots were drawn off from each sample, which had been di l u t e d to 50 ml. Each aliquot was counted in i t s entirety in a Sedgewick-Rafter c e l l at 100X magnification on a Le i t z Labourlux II® compound microscope (Wetzel & Likens 1979). This method was unacceptable because of the small t o t a l number of individuals counted (Lund e_t a_l. 1958), and because of the high degree of variation between replicate 38 aliquots. Therefore after week 1 of February the procedure was changed. However, these data were u t i l i z e d , because of the low numbers of zooplankton present in the lake at that time. Any other enumeration method would not have greatly improved the precision of these estimates without f i r s t increasing the orignal sample size taken in the f i e l d (Lund et a_l. 1958). In the second enumeration method each sample was f i r s t d i l u ted to 50, 100, 200, or 400 mis, depending on the densities of zooplankton present. Samples were then randomized by s t i r r i n g them numerous times in alternate directions after which they were immediately poured off into a 10 ml sedimentation chamber. After at least 30 min. s e t t l i n g (Wetzel & Likens 1979), the entire chamber was counted at 80X magnification with the Zeiss® inverted microscope. Using this method, the t o t a l number of zooplankton counted ranged from 252 to 3748 individuals per aliquot depending on the biomass of zooplankton in the sample and the d i l u t i o n factor. This d i l u t i o n factor was chosen to minimize the enumeration time, while counting at least 200 of the dominant cladoceran species and 40 of the dominant copepods. The larger number of zooplankton counted makes the second method more accurate since i t is the t o t a l number of individuals that are counted which determines the accuracy of the count (Lund et a l . 1958, Vollenweider 1974, Venrick 1978a; but see 3.2.2 for Discussion). 39 4. STATISTICAL CONSIDERATIONS For the analysis of plankton samples, counts from single aliquots were taken as representative of the samples from which they were drawn. The raw counts of replicate samples were averaged and from this mean was derived a standard error and 95% confidence l i m i t s , assuming a l l plankton were dis t r i b u t e d randomly in a l l stages of subsampling (Lund et a_l. 1958; see 3.2.2). These estimates were then multiplied by the appropriate d i l u t i o n factor and then converted to numbers per ml. Abundance and colony size estimates per depth were summed and averaged respectively, to obtain estimates for the entire water column each week. However, the individual estimates were not weighted by the proportion of the entire lake volume occupied by the strata that each represented. Such a weighting is required because data gathered from a station are i m p l i c i t l y extrapolated to the rest of the lake (Dr. W. E. N e i l l pers. comm.). This topic i s dealt with in d e t a i l in App. W, where i t i s demonstrated that when the results are so weighted, the interpretations and conclusions of this thesis are not altered but rather strengthened. Data analysis and manipulation was carried out on the U.B.C. computing system using the M.I.D.A.S. (Michigan Interactive Data Analysis System) s t a t i s t i c a l package. S t a t i s t i c a l tests were made at the 5% probability l e v e l . A l l other d e t a i l s on these tests w i l l be outlined in subsequent chapters and appendices, where appropriate. 40 III. RESULTS AND DISCUSSION 1. PHYSICO-CHEMICAL FACTORS 1.1 Temperature Lake temperature rose gradually and uniformly throughout a l l depths from the beginning of January to the last week of March. Ice formed only b r i e f l y in the beginning of February and then only around the perimeter of the lake. During the f i r s t week of A p r i l there was a rapid r i s e in temperature in the upper 1.5 m of the lake, from 9° to 12°C (Fig. 5). These changes in lake temperature p a r a l l e l e d the changes in maximum daily a i r temperatures and the hours of da i l y sunshine (Figs. 6 & 7; App. C). and correspond to the onset of s t r a t i f i c a t i o n in the lake (Wetzel 1975). 1.2 Lake Transparency And Light Extinction Eighty percent of the incident l i g h t was absorbed within the f i r s t metre of the lake. By the lake's maximum depth (3.5m), up to 98% of surface l i g h t had been lost (Fig. 8; App. D) The entire volume of the lake can be considered part of the euphotic zone, as l i g h t levels throughout the water column were rarely lower than 1% of surface irradiance (Cole 1983). Secchi disc readings ranged from 1.1m to 2.4m throughout the sampling period (Fig. 9). Summer readings were in the range of 1.1m. These Secchi readings are below the normal range for lakes in general (2 to 10m; Wetzel 1975) and are cer t a i n l y due to the dystrophic nature of the lake. 41 1.3 Soluble Reactive Phosphate Levels At no time did soluble reactive phosphate (PO„-P) levels drop to undetectable levels during the sampling period (Fig. 10; App. E). Consequently, PO„-P can not be considered l i m i t i n g (Lehman 1976). Mean PO„-P concentrations ranged from 1.3 to 6.7 g/L during these four months. V a r i a b i l i t y between samples was greatest during the peak blooms of Dinobryon species. Notably, the PO„-P levels were higher and most variable during the onset of Dinobryon declines. (see Figs. 11,12) 42 0 ~ 1 E Q 2 " 7 / 8 f 5 6 5 56 0 3 -7 8 9 9 101112 \ \ 1 \ I i i—i | i—r—i—i—|—i—p 0' I I E 1 CL CU O 2 -131514 5 56 7 8 9 9 101112 i i i I— i — i—r—|— i i i i | i i—i Jan Feb Mar Apr F i g u r e 5 - Isotherms (°C) S t a t i o n s I & I I , Como Lake - January t o A p r i l 1983. 43 20-1 LU cr. ZD UJ Q_ U 5 -A A A A A A A A A T J a n Feb T M a r A A A A A A A 1 A p r Figure 6 - Maximum dail y temperatures of Como Lake area. January to A p r i l 1983. Arrows indicate sampling dates. Source; E.C. - A.E.S. 1983. 15-1 1 0 -cr z> o X • f T f f f f f f f T T T T T T Jan Feb M a r A p r Figure 7 - Daily duration of bright sunshine Como Lake area. January to A p r i l 1983. Arrows indicate sampling dates. Source; E.C. - A.E.S. 1983. 44 F i g u r e 8 - P r o f i l e s of the p e r c e n t s u r f a c e i r r a d i a n c e r e m a i n i n g per d e p t h . S t a t i o n s I & 11 - Como Lake, January t o A p r i l .1983. 45 0 3 - . - i — | — i— r — i—|— i — i — i — i — | — i— r 0 — 1 E 3 I—I—I—|—I—I—I—I I I I | I I J a n Feb Mar Apr Figure 9 - Secchi disc p r o f i l e s . Stations I & II, Como Lake - January to A p r i l 1983. 46 Figure 10 - The weekly mean concentration of soluble reactive phosphate. Depths 1, 2, & 3m, Stations I & 11 combined - Como Lake, January to A p r i l 1983. V e r t i c a l bars designate standard errors. 47 2. DINOBRYON POPULATION AND COLONY DYNAMICS 2.1 Species Occurrence Two species of Dinobryon bloomed during the spring in Como Lake, D. cylindricum and D. divergens. A t h i r d species, D. bavaricum Imhof, also was present but only rarely - fewer than half a dozen colonies were observed throughout the entire sampling period. There was no s i g n i f i c a n t difference in c e l l volumes within or between the two predominant species (Table I II; App. F ) . Biomass comparisons can therefore be made in terms of c e l l and colony densities alone. SPECIES DATE MEAN SE N D. cylindricum Mar 3 195.29 6.498 99 Apr 7 201.62 7. 187 50 D. divergens Mar, 17 194.16 11.881 1 00 Apr 7 172.92 8.376 51 Table III - C e l l volumes ( /<m3) of D. cylindricum and D. divergens. 2.2 Temporal D i s t r i b u t i o n And Abundance 2.2.1 D^ cylindricum The population d i s t r i b u t i o n of D. cyli n d r icum i s bimodal (Figs. 11 & 12; Apps. G, I ) . The f i r s t and greater peak density occurred during the f i r s t week in March. A second maximum took place in the second week of A p r i l . Between these two peaks was 48 a three week period of very low densi t i e s . Colonies of D. cylindricum were present in small numbers from the beginning of the sampling period. With an i n i t i a l increase in lake tempratures this population increased s l i g h t l y by the end of February. This is may be a euplanktonic population originating from blooms of the previous f a l l (pers. obs.), that have overwintered. But given the explosive increase in D. cylindr icum numbers in the f i r s t week of March, t h i s population probably does not represent a s i g n i f i c a n t proportion of the seed population for that spring. The March increase is probably indicative of a massive influx of colonies originating from benthic statospore populations. The increasing spring insolation triggers the simultaneous germination of these statospores, resulting in a sudden appearance of rapidly increasing Dinobryon populations (Sheath e_t a l . 1975). On the other hand, this explanation is probably not applicable to the second population pulse of p. cylindricum in week 1 of A p r i l . Indications that the population was already increasing in the previous week; the fact that the increase in the population, in one week, was one f i f t h of the increase that occurred in the f i r s t pulse in the same period of time; the sudden increase in lake and a i r temperatures as well as the increase in the hours of da i l y bright sunshine in the days prior to sampling; and especially the coincident increase in D. divergens populations argues that the second maximum of D. cylindricum results from enhanced -growth of the exis t i n g populations due to increased l i g h t and temperature levels rather 49 than from a second germination of benthic statospores. 2.2.2 divergens Colonies of D.4 divergens were rare before the f i r s t week of March, only appearing sporadically in samples (Fig. 11, 12; Apps. H, J ) . The population was decidedly unimodal, a single maximum occured in the f i r s t week of A p r i l . Following t h i s peak the population f e l l sharply at a rate which exceeded that of i t s population growth. 2.2.3 V e r t i c a l D i s t r i b u t i o n The populations of both species were concentrated in the upper metre of the lake (Fig. 13, 14; Apps. G, H, I, J ) . This is not surprising considering the markedly deminished l i g h t i n t e n s i t i e s in the lower depths (Fig. 8). The population dynamics of both Dinobryon species c i t e d above were apparent at a l l depths, a l b e i t somewhat attenuated with increasing depth. The only notable exception to this occurred in the f i n a l weeks of February. At this time D. cylindricum's densities decreased in the lower 2 m while they increased in the upper metre. 50 I I I I 1 1 I I j a n 1 f e b 1 i i i r m a r 1 a p r 1 F i g u r e 11 - Colony d e n s i t i e s . D. c y l i n d r i c u m ( ) and D. d i v e r g e n s (• _ ) , Como Lake - January t o A p r i l 1983. E r r o r b ars are c o n t a i n e d w i t h i n the symbols. 51 Figure 12 - C e l l densities D. cylindricum ( ) and D. divergens ( : ), Como Lake - January to A p r i l 1983. Error bars are comtained within the symbols. 5 2 0 D. cy l ind r i cu m # C o l o n i e s / m l E 1 x Q. UJ O 2 - -0 - r T—i—i—|—I—i—i—|—i—i—I—i—|—i—r ivergens # C o l o n i e s / m l 1 ! + x CL U Q 2 " 3--15 5 i i i I I i i—I—i—r J A N 1 F E B 1 M A R T—T 1 I I 1 A P R 1 Figure 13 - P r o f i l e s of colony d e n s i t i e s . D. cylindricum and D. divergens, Como Lake - January to A p r i l 1983. 53 F i g u r e 14 - P r o f i l e s of c e l l d e n s i t i e s . D. c y l i n d r icum and p. d i v e r g e n s , Como Lake - J a n u a r y t o A p r i l 1983. 54 3. COLONY MORPHOMETRICS 3.1 Colony Shape Differences in the colony shape of both species are seen in the s t a t i s t i c s of the entire data set, consisting of 2055 colonies of D. cylindr icum and 1238 colonies of D. divergens (Table IV). A l l the colony variables measured are s i g n i f i c a n t l y d i f f e r e n t between the two species (App. K). (Given the large sample sizes, this result i s not surprising.) The magnitude of the differences between species varies with the variable. There is very l i t t l e difference between the average number of lor i c a s per colony in each species and yet there are d i s t i n c t differences in mean colony lengths and widths. D. divergens colonies are wider and shorter than D. cylindricum. In t e r s p e c i f i c differences in l o r i c a shape primarily account for the differences in colony shape. Although the l o r i c a length in D. divergens is s i g n i f i c a n t l y smaller than that of D. cylindricum (Table V; App. L), the differences between the two are very small and cannot e n t i r e l y account for the differences in colony dimensions. Besides, were l o r i c a length the major determinant of colony dimensions then D. divergens colonies would be smaller in both length and width and not only the former. The two species show considerable difference between the shape of their l o r i c a s which result in corresponding differences in the way in which their respective l o r i c a s are orientated to one another. The basal portion of p. divergens l o r i c a s , unlike 55 Variable D. cyindricum D. divergens # Loricas Range N 14.09 (0.208) 1 - 15 2055 13.32 (0.323) 1 - 91 1 238 Colony Length ijmm) Range N 160.90 ( 1 . 173) 20.3 - 353.8 2055 136.85 ( 1 .485) 23.2 - 319.0 1 238 Colony Width (/<m) Range N 61.62 (0.741 ) 8.7 - 214.6 2055 67.63 ( 1 . 182) 8.7 - 237.8 1 237 # Empty Loricas Range N 2.43 (0.067) 0 - 1 8 2055 2.92 (0.024) 0 - 1 5 1 237 # Statospores Range N 0.015 (0.0052) 0 - 7 2055 0.258 (0.0237) 0 - 7 1238 # Loricas per Longest Branch Range N 4.86 (0.035) 1 - 1 0 2052 4.58 (0.051) 1 - 10 1 237 Table IV - Colony variables - s t a t i s t i c s . Bracketed values indicate standard errors. See text for detaiIs. SPECIES DATE MEAN SE N 5- cylindricum Mar 3 39.98 0.203 1 12 Apr 7 40.26 0.320 65 D. divergens Mar 1 7 38.47 0.239 1 1 1 Apr 7 39.42 0.374 72 Table V - Measured l o r i c a lengths of D. cylindricum and D.divergens. Length units are in yn.m. "N" equals the number of l o r i c a s measured for each estimate. See text for d e t a i l s . 56 those of D. cy l i n d r icum, i s at an angle with respect to i t s upper portion. This angle is generally on the order of 15 - 20° but i t can be as high as 90° (Ahlstrom 1937). It i s the basal portion of the l o r i c a which s i t s within the mouth of the preceeding l o r i c a . The upper portion of each l o r i c a of D. divergens is therefore oriented at an angle with respect to the previous l o r i c a . Generally, branches in D. divergens would be less linear than those of D. cylindricum, becoming increasingly less so as the number of l o r i c a s per branch increased. This is i l l u s t r a t e d in the estimates of l o r i c a lengths derived from the lengths of the longest colony branch (colony length) and the number of l o r i c a s in those branches (Fig. 15, Table VI). Overall the estimate of l o r i c a length (derived as above) is s i g n i f i c a n t l y smaller in D. divergens (Table VI; App. M). But as the number of l o r i c a s per colony and SPECIES MEAN SE N D. cylindricum 33.36 4.307 2052 D. divergens 30.50 4.263 1237 Table VI - Estimated l o r i c a lengths. Length estimates are in units of /*.m. See text for d e t a i l s . per branch decline to low levels at' the end of A p r i l (see 3.3.2), the mean estimate of l o r i c a length for each species converges (Fig. 15). Obviously, as the number of l o r i c a s per longest branch declines, the eff e c t of D. divergens l o r i c a orientation declines proportionately. When the number of 57 lo r i c a s per longest branch i s small the estimate of l o r i c a length in D. divergens w i l l approach the estimates derived from D. cylindricum colonies, as their true l o r i c a lengths are sim i l a r . The effects of l o r i c a shape and orientation would also be evident in the colony. Colony morphology is the result of many such branches described above. With comparable numbers of l o r i c a s , D. divergens colonies would be wider and shorter than D. cylindricum. This i s i l l u s t r a t e d in Fig.16,17; App.N,0. 58 Figure 15 - Temporal variation in l o r i c a length estimates. D. cylindricum ( ) and D. divergens ( ). Error bars are given unless contained within symbols. 59 Figure 16 - Linear regression of colony width on colony size (#LPC). D. cylindricum ( ) and D. divergens ( ). See App. N for d e t a i l s . 60 t — i — i — r — 10 20 30 40 50 60 70 80 # L P C Figure 17 - Linear regression of colony length on colony size (#LPC). D. cylindricum ( ) and D. divergens ( ). See App. 0 for d e t a i l s . 61 3.1.1 Colony Size - Temporal Variation Throughout the spring p. divergens exibited greater range and variance in colony size (#LPC) than D. cylindricum. Frequency d i s t r i b u t i o n s of the (#LPC) i l l u s t r a t e this point. D. divergens had a larger proportion of small and large colonies (Fig. 18; App. P,Q). Also evident in t h i s graph is that for D. divergens the largest proportion of i t s colonies were small in the 4-8 LPC range. In contrast, the majority of D. cylindr icum colonies were spread over a broader range from small to medium colonies (4-16 LPC). The temporal changes in the colony size of each species were marked and d i s t i n c t (Fig. 19). Colony size in p. divergens decreased throughout i t s occurrence (23.2-6.7 LPC). In contrast, The colony size changes of p. cylindr icum exibited three d i s t i n c t phases. During the f i r s t pulse the mean colony size rose gradually (9.4-14.2 LPC) with the population increase, only to f a l l to 6.2 LPC when the population f e l l . In the subsequent two weeks when the population numbers remained depressed, the colony size jumped f i r s t to 21.8 LPC and then climbed further to 24.7 LPC. In the f i n a l phase when densities increased to a second maximum and then f e l l , the average colony size declined to 7.0 LPC. 62 3.1.2 Colony Size - Spatial D i s t r i b u t i o n Overall colony size decreased s i g n i f i c a n t l y with increasing depth (Fig. 20; Apps. P, Q). The differences between depths were more obvious on some dates than others, especially during the f i n a l week of February for D. cylindricum and the th i r d week of March for D. divergens. While the pattern of colony size change was generally similar over the three depths for each species, one notable exception occurs. For a three week period from the fourth week of March to the f i r s t week of A p r i l the colony size of both species remains r e l a t i v e l y constant at one metre. This s t a b i l i z a t i o n of mean colony size was not found deeper in the water column, nor does i t occur on other dates. 3.1.3 Concurrent Changes In Colony Size And Populations The individual pulses of both Dinobryon species follow the same general pattern in the way that their mean colony size changes as their population changes. During the onset of each population pulse, when densities are s t i l l very low, the mean colony size is at i t s largest. Thereafter colony size generally f a l l s and does so most rapidly when the population begins to decline (Fig. 21). Differences between pulses are largely ones of the timing of the decline in colony size r e l a t i v e to the decline in population densities. D. cylindricum colony size remains r e l a t i v e l y constant in the weeks prior to, and during, the f i r s t 63 population maximum. It then declines with the decline in population. During the second pulse, the colony size begins to decline two weeks before the population does so. In contrast, D. divergens colonies decline in size throughout i t s population pulse. When the pulses of the two species are compared, i t i s seen that the patterns of change in colony size and densities in D. cylindricum are i n i t i a l l y out of phase with that of D. divergens, but that by the end of A p r i l the two coincide. The f i r s t pulse and colony size of D. cyindricum decline just as the population of D. divergens begins to increase. During the pivo t a l fourth week of March, colony size in D. cylindricum increases dramatically when i t s densities are at their lowest. At exactly the same time the colony size of D. divergens drops sharply as i t s population continues to increase. The populations of both species subsequently grow with the second maximum of D. cylindricum occurring one week after that of D. divergens has begun to f a l l rapidly. Both species thereafter decline together and to similar colony and population densities in the la s t two weeks of A p r i l . The seemingly complex and concurrent i n t e r s p e c i f i c changes in population and colony size of these two species are, in e f f e c t , the repetition of a simple pattern with minor variations in timing - that of large colonies declining to smaller colonies as populations wax and wane. 64 30 CD O o o ^ 10 T T T T I I I I I I I I I 20 AO -# Loricas per Colony 1 1 1 i 1 n n i i 60 80 100 Figure 18 - Colony size frequency d i s t r i b u t i o n s . D. c y l indr icum ( ) and D. divergens ( ) for the entire sampling period; Depths 1, 2, & 3m - Station I combined. 65 Figure 19 - Overall temporal changes in the colony si z e . D. cylindricum ( ) and D. divergens ( ) averaged over 1, 2, & 3m, Station I - Como Lake, January'to A p r i l 1983. Error bars are given. 66 3 4 -3 0 -26-22-| 1 8 -UH 1 0 -6 -2-1 Im 3 4 -3 0 ->-o 26-o ^ 22-Q. to 1 8 " o * 10-6 -2-3 4 - | 3 0 26 22 18 1 4 -1 0 -6-2 I I I | I I I | I I I I | I I I | 2m t i i i I i i i | i i i i | i i i | 3m i i i i i i i i i i i i I i i i i jan • feb ' mar ' apr ' F i g u r e 20 - Temporal changes i n c o l o n y s i z e per depth. D. c y l i n d r i c u m ( ) and D. d i v e r g e n s ( ) a t each s a m p l i n g d e p t h , 1,2 & 3m, S t a t i o n I - Como Lake, January t o A p r i l 1983. E r r o r b a r s a r e g i v e n . 67 3H 30 o 26 o <b CL w 18H o (_> c u o * 10-6 -2 -• * i r 160 H 15Q U 0 130H 120 110 100-: 90-2 80 O £ 7 0 H I 60H o <-> 50-1 AO 30^ 20 10 i 1 1 1 1 1 r r r r i 1 ! ' I ' 1 1 ' ' ' I 1 1 ' * l jan ' feb 1 mar • apr ' Figure 21 - Contemporaneous changes in colony size and colony den s i t i e s . D. c y l indr icum ( ) and D. divergens ( ) - a l l depths in Station I combined - Como Lake, January to A p r i l 1983. Error bars are given. 6 8 3.2 Temporal Changes In Other Colony Variables It is obvious that for the morphometric variables such as colony length and width (Fig. 22) and the number of lo r i c a s per longest branch (Fig. 23), the patterns of temporal variation are similar to that of colony size (Fig. 19). Of the remaining variables, number of empty l o r i c a s (Fig. 24) and the number of statospores per colony (Fig. 25), several observations can be made Both variables account for only a small proportion of the ov e r a l l number of l o r i c a s per colony throughout most of the sampling period (see also Table IV). The number of empty l o r i c a s per colony does make up an increasing percentage of the colonies when colony size declines, but this is not so much the result of greater numbers of empty l o r i c a s as i t i s the result of the smaller t o t a l numbers of l o r i c a s per colony. (See Appendix R for d e t a i l s of these variables.) Statospore production remained very low in both species but p a r t i c u l a r l y so in D. cyl i n d r icum. Notably though, the means and ranges in the number of statospores per colony of both species increased during population growth, but not during population declines. 69 220-1 200-1 8 0 -160 -U 0 -J 2 0 -1 0 0 -8 0 -6 0 -4 0 -20 -2 2 0 " 2 0 0 -1 8 0 -160-U O -k 1 2 0 -100 -8 0 -6 0 -4 0 -2 0 -> ' H ~ H length width I I | I I I | I I I B \ length \ \ 9 ^ V V width i I I I l l I I I l I l | I I I jan feb mar apr Figure 22 - Temporal variation in colony length and width. D. cylindricum - A; D. divergens - B. Standard errors are indicted by v e r i c a l bars unless contained within the symbols. 10.0-9.0-8.0-7.0 6.0-5.0-4.0-3.0" 2.0-1.0-70 I , ' I i i r i i i i 10.0j 9.0-8.0 7.0-6.0-5.0-4.0-3.0-2.0-1.0 B \ \ m r jan i i r mar apr F i g u r e 23 - Temporal v a r i a t i o n i n number of l o r i c a s per l o n g e s t branch. D. c y l i n d r i c u m - A; D. d i v e r g e n s - B. S t a n d a r d e r r o r s a r e i n d i c a t e d by v e r t i c a l b a rs u n l e s s c o n t a i n e d w i t h i n the symbols, 71 34-30-26-22-18-U -10-6-2-34-30-26-22-18-U -10-6-2 # l o r i c a s i / i # e m p t y A— i i i i i i i r I 1 1 1 I B # l o r i c a s \ •#empty I I I I I I I I i I i i I I i I I j a n feb m a r ap r Figure 24 - Temporal variation in number of l o r i c a s and number of empty l o r i c a s per colony. D. cylindricum - A; D. divergens - B. Standard errors are indicated by v a r t i c a l bars unless contained within the symbols, 100-90-80-70-60-o " 50-40-30-20-10-100-90-80-70-60-o v. — 50-40-30-20-10-72 T T T i r * T * i i r B I. I I I I I I jan feb A • • • • L l i i i r i r mar apr I Figure 25 - Temporal va r i a t i o n in percentage of statospores per colony. D. cylindricum -A and p. divergens -B. A l l standard errors are contained within the symbols. Arrows indicate ranges. 73 4. ZOOPLANKTON Twelve species of zooplankton were i d e n t i f i e d and enumerated from the samples of both stations (Table VII). Of these, three occurred rarely - less than 5 /m2. The temporal d i s t r i b u t i o n s of the remaining nine species (including copepod nauplii) are i l l u s t r a t e d in Figures 26 through 2 8 . The data ROTIFERS Asplanchna priodonta  F i l i n i a sp. K e l l i c o t t i a bostoniensis  Keratella crassa  Keratella quadrata  Lecane sp. Polyarthra sp Trichocerca sp CLADOCERANS Bosmina coregoni  Daphnia longispina COPEPODS Diacyclops thomasi Diaptomus sp. Naupli i Cboth species) Table VII - Predominant zooplankton species occurring in Como Lake - January to A p r i l 1 9 8 3 from which they were derived, including abundance estimates for each depth, are detailed in Appendix S. With the exception of Asplanchna priodonta which also had a pulse in the beginning of February, r o t i f e r populations increased only after the t h i r d week of March (Fig. 2 6 ) . Their population dynamics are of three types; unimodal - peaking 74 during the second and t h i r d week of A p r i l ( K e l l i c o t t i a  bostoniensis; F i g . 26B); bimodal - peaking in the fourth week of March and again in A p r i l (Asplanchna priodonta; Fig. 26A, Kerat e l l a quadrata; F i g . 26C); and increasing through to the end of A p r i l (Keratella crassa; F i g . 26D, Polyarthra sp; F i g . 26E). Both cladoceran species were present throughout the spring period but their dynamics were very d i f f e r e n t (Fig. 27). The much smaller Bosmina coregoni increased in number only after the t h i r d week of March (Fig. 27 A). Its population continued to grow through to the end of A p r i l at Station I while at station II i t peaked during the second week of A p r i l . Estimates of Daphnia longispina abundances at the two stations fluctuated out of phase with each other u n t i l the t h i r d week of March (Fig. 27 B). At t h i s time station II densities rose sharply while densites at station I remained r e l a t i v e l y constant. In the weeks following station II densities declined while those of the f i r s t station went on to peak at the end of March and beginning of A p r i l . Densities at both stations f e l l to comparable levels by the t h i r d week of A p r i l . Diacyclops thomasi was the only copepod present in any appreciable numbers in the adult stage (Fig. 28 B). It was present in the lake from the beginning of January but only rose in abundance after February. Its densities increased u n t i l the t h i r d week of March. The only discrepancy between the estimates of abundance between the two stations occurred during t h i s week, when unusually large numbers appeared at three metres in station I (App. T). Considering the uniqueness of t h i s event, i t i s 75 200 J 100 J E \ in ' 1 100 > "D C O 200 J 100 J J 1 1 r 1 1 J i l l | i I i i I I r 400 J 300 J i T l P i ' H m l i i i 200 J 100 B & Hi i i I i I 1 1 1 I I I I I I I jan i n p feb 1 n mar •i—i-I «-: 300. 200 J 1 0 0 J a pr i i i jan feb mar apr F i g u r e 26 - Temporal d i s t r i b u t i o n of r o t i f e r s p e c i e s . A s planchna p r i o d o n t a - A ; K e l l c o t t i a b o s t o n i e n s i s - B : K e r a t e l l a q u a d r a t a - C ; K e r a t e l l a c r a s s a - D ; P o l y a r t h r a sp.-E S t a t i o n I (• •) S t a t i o n I I ( - - - - - ) . 76 F i g u r e 27 - Temporal d i s t r i b u t i o n of c l a d o c e r a n s p e c i e s . Bosmina c o r e g o n i e -A; Daphnia l o n g i s p i n a -B. S t a t i o n I (— S t a t i o n I I ( - - - - - ) . ) M L ) 77 Figure 28 - Temporal d i s t r i b u t i o n of copepod species. Copepod nauplii -A; Diacyclops thomassi -B; Diaptomus sp. -C. Station I ( ) Station II ( ). 78 probably a transient and l o c a l i z e d high density patch. As such i t i s not representative of the densities at that station and w i l l be ignored. Therefore the densities of th i s species can be considered to have s t a b i l i z e d after the t h i r d week of March u n t i l the last two weeks of A p r i l , after this there is a sudden large increase in the population. Copepod nauplii were very abundant throughout the sampling period, especially a f t e r February (Fig. 28A). They were p r i n c i p a l l y concentrated in the lower depths of the lake, at 3 m and below (App. S). 79 IV. THE ORIGINAL HYPOTHESES RECONSIDERED 1 ._ MODIFICATION THE ORIGINAL HYPOTHESES The o r i g i n a l hypotheses postulated that the decline of Dinobryon populations resulted from either a decline in the mean colony size or an increase in the numbers of larger zooplankton, which rendered colonies more susceptable to losses through grazing. On the basis of the results, neither hypothesis i s f u l l y supported on i t s own. Mean colony size generally declines during the population pulses of two common spring species of Dinobryon (Fig. 21). But the timing of such declines, r e l a t i v e to the f a l l of population numbers, varies from pulse to pulse. The decline of mean colony size of D. divergens, and of the second pulse of D. cylindricum, before the decline in population numbers, supports the f i r s t hypothesis. Progressively smaller colonies at that time would have been subjected to increasing grazing pressure from the growing numbers of smaller zooplankton. In contrast, mean colony size remained r e l a t i v e l y constant during the f i r s t pulse of D. cylindricum u n t i l the population f e l l . The decline in colony size and population coincided with the increase of Diacyclops thomasi, a larger zooplankton. Therefore this supports the second hypothesis. The p a r t i a l support for the o r i g i n a l hypotheses suggests that these hypotheses can be modified and need not be e n t i r e l y dismissed. Any new hypothesis would have to be consistent with the d i s t i n c t i v e features of the data, including: (1) the overa l l 80 decline of mean colony size in Dinobryon pulses; (2) the variations in the timing of each individual pulse; (3) the timing of D. cylindricum pulses with respect to the single pulse of D. divergens; (4) the relationship of these pulses to the dynamics of the zooplankton community. 2. REFORMULATION OF THE HYPOTHESES 2.1 An Explanation For Colony Size Declines Because a colony is composed of l o r i c a s that are fused together, a colony w i l l continue to grow, or stay the same size, unless that colony i s physically broken apart. The decline in mean colony size of a population represents either the loss of large colonies or their fragmentation into smaller ones. Certain aspects of the data suggest that grazing may be linked to colony size decline. The increase in adult and copepodite stages of Diacyclops thomasi in week 3 of March and week 3 of A p r i l coincides with marked declines in the colony size and densities of D. cylindricum. A s t a b i l i z a t i o n in the numbers of this zooplankton from week 3 of March through week 1 of A p r i l coincides with the s t a b i l i z a t i o n in the colony size of both Dinobryon species at one metre. To e f f e c t a decline in the colony size of a population of Dinobryon zooplankton would have to be s u f f i c i e n t l y abundant and capable of breaking up or eliminating large colonies. Of a l l the zooplankton that are present only Diacyclops thomasi meets 81 these c r i t e r i a . Although Daphnia longispina and Asplanchna  priodonta are capable of capturing larger p a r t i c l e s because of their larger r e l a t i v e size (Lund 1965, Burns 1968, Webster & Peters 1978, Nadin-Hurley & Duncan 1976, Gliwicz 1980, Gliwicz & Siedlar 1980, Holm et a_l. 1983), their population dynamics do not coincide with changes in the mean colony size nor the numbers of both Dinobryon species. The remaining smaller zooplankton are limited in their clearance rates and their capacity to both capture and ingest large p a r t i c l e s (Gliwicz 1969a, 1969b, 1977 Morgan et a l . 1980). As such, their effect on Dinobryon populations would be r e s t r i c t e d to the smaller colonies and then only when the i r own populations are large. Diacyclops thomasi i s an omnivorous zooplankton whose copepodite and adult stages are capable of consuming not only Dinobryon colonies (Moore 1979a), but also r o t i f e r s , copepod nauplii and other zooplankton species (McQueen 1970, Gliwicz 1974, Morgan et aJL. 1980). This species, l i k e other pelagic cyclopoid copepods, is a raptoral feeder which ambushes i t s prey and seizes them with i t s feeding appendages. Prey that are not too large, are consumed whole, otherwise they are torn apart by the feeding appendages and eaten piecemeal. These zooplankton are size s e l e c t i v e feeders, p r e f e r e n t i a l l y attacking the larger of the available prey ( M i l l e r 1952, Fryer 1957, Moriarty e_t a l . 1973, Moore 1979a, Morgan et a l . 1980). Size sel e c t i v e predation by D. thomasi would not only eliminate the larger colonies and decrease the mean colony size of the population, but i t would also prevent the smaller 82 colonies from reaching larger sizes. This would render a greater proportion of the population susceptible to grazing by smaller zooplankton. When these smaller zooplankton are present in s u f f i c i e n t numbers then the grazing pressure on a l l colony sizes could be great enough to result in the decline of the Dinobryon populations. Modification of phytoplankton colony size by zooplankton grazers has been demonstrated elsewhere, primarily in marine organisms (Enright 1969, Martin 1970, Parsons & Seki 1970, O'Connors et a l . 1976, Donaghay & Small 1979, Alcaraz et a l . Paffenhofer e_t §_1 . 1982), but also in fresh water organisms (Fryer 1958, Moriarty et a_l. 1973 , Kryuchkova & Rybak 1980). In the short term (24 h), zooplankton grazing results in an i n i t i a l decline in mean colony size of a phytoplankton population (O'Connors et a l . 1976). However, over a longer period of time, with constant zooplankton densities, there is a s t a b i l i z a t i o n in phytoplankton colony size indicative of a balance between colony growth and their fragmentation by zooplankton. The s t a b i l i z a t i o n of the mean colony size in both Dinobryon species (week 4 March - week 1 A p r i l ; 1 m), when the densities of Diacylops thomasi remained r e l a t i v e l y constant and may r e f l e c t an analogous equilibrium between the growth of Dinobryon colony size and th e i r breakup by Diacyclops thomasi in the f i e l d . 0 83 2.2 Applying The New Hypothesis To The Results The increase in Diacyclops thomasi, Daphnia longispina and Bosmina coregoni populations could thus account for the decline in the colony size and population of D. cylindr icum during i t s f i r s t pulse (Fig. 22; 29, 30B). • Diacyclops thomasi would consume and/or break up the larger colonies of the pulse, while the smaller colonies and colony fragments would be eaten by the other zooplankton. After two weeks, only a much depleted population of predominently small colonies would remain (Week 3, March). With the coincident increase of the D. divergens population, the largest remaining colonies of D. cylindricum would be passed up by Diacyclops thomasi for the much larger colonies of D. divergens. With the continued consumption of smaller colonies by other zooplankton species, the mean colony size of D. cylindricum would increase, even as i t s population density continued to decline (Week 4, March). Given the patchy nature of both zooplankton and phytoplankton d i s t r i b u t i o n s , these rare large colonies would be infrequently encountered by Diacyclops thomasi. Therefore the mean colony size of D. cylindricum would remain high u n t i l i t became more numerous (Weeks 1,2 Ap r i l ) or a l t e r a t i v e l y , u n t i l the densities of Diacyclops thomasi increased (Weeks 3,4 A p r i l ) . Open to question here is the o r i g i n of large colonies at the begining of each pulse, p a r t i c u l a r l y those of D. divergens. There are two possible explanations that are not necessarily mutually exclusive. Large colonies may be formed on the lake bottom after germination, but prior to their moving up into the 84 water column. Such an explanation has previously been suggested for the appearance of large colonies in Aphanizomnion flos-aquae (Lynch & Shapiro 1981). On the other hand, some i n i t i a l colonies may escape immediate grazing by cyclopoid copepods because of their patchy d i s t r i b u t i o n and low density. The absence of data on the post-germination events of colony formation, does not allow for a choice between these two alt e r n a t i v e s . The answer to the question of why the mean colony size of Dinobryon populations i s i n i t i a l l y large must be l e f t to future research. The above explanation can account for the colony and population dynamics of D. cylindricum. However, i t does not by i t s e l f explain the growth of the p. divergens population throughout March since the zooplankton community continued to increase after the decline of the f i r s t pulse of D. cylindricum. A colony's width is more important than i t s length in determining i t s fate in encounters with zooplankton grazers. For cyclopoid copepods, the wider i t s prey the more l i k e l y that prey w i l l be broken up prior to ingestion (Fryer 1957, Moriarty et a l . 1973). Regardless of o v e r a l l body size, cladocerans are limited to ingesting r e l a t i v e l y small p a r t i c l e s of narrow width (Burns 1968, Gliwicz 1974, Nadin-Hurley & Duncan 1976, Morgan et a l . 1980, Ferguson et a l . 1982, Holm et a l . 1983). Wider p a r t i c l e s , such as colonies, i f captured by the f i l t e r i n g appendages would be broken up in the process of ingestion or by rejection by the postabdominal claw should they obstruct the 85 mouth region. In either case, wider colonies, such as those of D. divergens, would be more readily broken apart during grazing. More c e l l s of these colonies would be l i k e l y to escape consumption, losses to grazing would be less, and population growth would continue as long as the smaller colonies could escape further grazing. With the continued growth of smaller zooplankton populations during the month of A p r i l , these smaller colonies would be consumed before they could reach larger sizes, and the population would therefore f a l l . In contrast to D. divergens, the narrower colonies of D. cylindricum would suffer greater losses during encounters with Diacyclops thomasi and the cladoceran zooplankton. Their narrower colonies would be more readily ingested by these zooplankton and fewer c e l l s per colony would escape. Their populations would therefore decline more readily with a smaller increase in the number of these grazers. 3. OTHER POSSIBLE EXPLANATIONS There are alternative p o s s i b i l i t i e s , to explain the decline in colony s i 2 i e of Dinobryon. Possible causes can be separated into those that involve the immigration or emigration of colonies and those that effect the addition or loss of l o r i c a s from colonies. An influx of small colonies recently derived from benthic statospores, or the eff l u x of large colonies by sinking out, 86 would lower the mean colony size of a population. Yet neither of these p o s s i b i l i t i e s i s supported to any degree by the data. D. cylindricum colony size does not decline with the rapid growth of i t s f i r s t statospore derived pulse, but rather as the population f a l l s (Fig. 21). Its second pulse, on the other hand, probably resulted from enhanced insolation and increased temperatures (Section 3.2.1), and therefore was not the result of statospore germination. The decline in colony size of p. divergens is evident from the onset of population growth and might i n i t i a l l y be attributed to the immigration of smaller colonies from statospores. This is e s pecially true considering the marked decrease in colony size that occurs with depth in weeks 3, 4 of March (Fig. 21). However i t would not explain the continued decrease in colony size throughout the pulse. Because smaller colonies would eventually grow in size, an increase in the mean colony size of the population would be ine v i t a b l e . As thi s i s not the case for D. divergens, i t is unlikely that the immigration of smaller colonies from statospores accounts completely for the decline in colony s i z e . The sinking out of large colonies would occur with a decline in their a b i l i t y to maintain their m o t i l i t y . A decline in the propulsive e f f i c i e n c y of colonies would result from the loss of c e l l s from the colony through sexual reproduction, physiological death or statospore formation. Yet empty l o r i c a s only make up a large proportion of the colonies when the colonies are small and the numbers of statospores per colony, at 87 any time, are very low (Figs. 24,25). The sinking out of large colonies i s therefore unlikely. Changes in the mean colony size can also r e f l e c t imbalances between the processes which add l o r i c a s to colonies and those which cause the l o r i c a s to be lost from colonies. A d e c l i n e in the rate of l o r i c a additions, ( i . e . , the reproductive rate), r e l a t i v e to the rate of l o r i c a losses would also result in a drop in the mean colony size. During the f i r s t pulse of D. cylindricum colony size declines with the population (Fig. 21). This could be the result of a declining reproductive rate. Yet in the other two pulses colony size declines even as their populations continue to increase. This i s not consistent with this explanation. A decline in the reproductive rate resulting in a decline in colony size therefore does not seem to be consistently supported by the data. An increase in loss rate r e l a t i v e to the reproductive rate i s therefore implicated by the res u l t s . For l o r i c a s to be lost from a colony, some physical disruption of the colony has to occur. Such a disruption could be the result of structural i n s t a b i l i t y of the colony as i t grows larger or i t can be caused by external factors such as water turbulence or grazers. Structural i n s t a b i l i t y can not explain the existence of colonies much larger than the average colony sizes in this and other data (Krieger-Berlin 1930). It would also be d i f f i c u l t to explain how structural i n s t a b i l i t y could result in progressively smaller colonies. Turning to turbulance, as the action of the sampling pump had no 88 discernable effect on the sizes of colonies, the comparatively miniscule turbulence in the lake is not l i k e l y to cause the breakup of colonies. In both of the preceeding cases, i t would also be d i f f i c u l t to envision how either could account for the i n t e r s p e c i f i c patterns of colony size changes, which are at times out of phase with each other (e.g., Fig. 19; weeks 1 - 4 of March). F i n a l l y , neither of these two causes could account for the decline in population numbers. Therefore only the loss of l o r i c a s due to grazers is l e f t and, with i t , the reformulation of the o r i g i n a l hypotheses that was considered above. 89 4. THE REVISED HYPOTHESIS Based on the preceeding arguments, the o r i g i n a l hypotheses can be modified as follows: Colony formation in the spring species of Dinobryon functions to minimize losses to zooplankton grazers. (A) Against smaller f i l t e r feeding species Dinobryon colonies minimize grazing losses by being too large to be e a s i l y consumed. The degree to which they reduce losses to these zooplankton depends upon their o v e r a l l size. (B) Against larger f i l t e r and raptoral feeders, colonies minimize losses by fragmentation, allowing some c e l l s to escape ingestion. Here, the degree to which colonies are e f f e c t i v e i s a function of l o r i c a morphology. Where l o r i c a s give r i s e to wider colonies, more c e l l s escape as colonies are broken up prior to, or during, ingestion. 90 V. REVIEWING THE NEW HYPOTHESIS 1. ASSUMPTIONS OF THE NEW HYPOTHESIS A number of assumptions underlie the arguments which led to the generation of the new hypothesis. The f i r s t assumption is that Dinobryon colonies are being consumed by the zooplankton. Secondly, when the colony size of a population declines, larger colonies are being s e l e c t i v e l y eliminated from the population, through fragmentation and/or ingestion. Thirdly that Diacyclops  thomasi i s the zooplankton that primarily causes the declines in the mean colony size of Dinobryon. If the above hypothesis is fundamentally correct, then there should be evidence in the o r i g i n a l data, as well as the unanalyzed phytoplankton samples of Station II, to substantiate these assumptions. To this end, further analyses of the o r i g i n a l data and of selected phytoplankton samples of Station II were undertaken. The d e t a i l s of these analyses, the i r results and consequences are examined in t h i s chapter. 2. MATERIALS AND METHODS 2.1 Zooplankton Gut Analysis Analyses of zooplankton digestive tracts were carried out by modifying a method used for r o t i f e r i d e n t i f i c a t i o n (Edmondson 1959). Zooplankton species from 1 m samples of Station I were separated into 15 ml test tubes, by the use of glass pipets and 91 a Wild M7® stereomicroscope. The test tubes were f i l l e d several times with d i s t i l l e d water to rinse the zooplankton, which were then transfered in lots of 10 - 15 individuals, to deep welled s l i d e s . A 1:1 solution of d i s t i l l e d water and commercial bleach (5.25% sodium hypochlorite) was then added and s t i r r e d . When the inner tissues of an individual were almost a l l dissolved, that individual was immediately removed from the sl i d e well and rinsed in d i s t i l l e d water. The time for dissolution depended on the species, i t s size and other unknown factors, and varied from 20 s to 2 min. Portions of the digestive tract were the la s t to dissolve and their contents were immediately observed at 100X and 1000X magnification using the Le i t z Dialux® compound microscope. Dinobryon l o r i c a s were observed in the undissolved portions of the gut in this manner (Fig. 29). However, the l o r i c a s themselves were also eventually dissolved by the solution, although at a higher bleach concentration ( 1 - 2 min in 100% bleach). Consequently, I was never certain whether the lack of l o r i c a s in the zooplankton guts was due to their d i s s o l u t i o n or their absence. In fact there were instances where statospores, but not l o r i c a s , were observed in the zooplankton. This method is therefore s t r i c t l y q u a l i t a t i v e . 92 2.2 Colony Size Frequency Distributions Frequency d i s t r i b u t i o n s of colony size (#LPC) were generated for both Dinobryon species, each week, from the pooled data of a l l three - depths of Station I. Each d i s t r i b u t i o n consisted of a histogram divided into colony size classes of 5 LPC. Also generated were weekly colony size class frequency d i s t r i b u t i o n s for both Dinobryon species combined. To obtain these, the weekly size class frequencies of each species were multiplied by the proportion of the entire Dinobryon population which was made up by that species. The proportion of the entire Dinobryon population made up by each size class, of each species, was thereby calculated. Summation of the proportions of each equivalent size classes of each species then resulted in a colony size frequency d i s t r i b u t i o n for a l l Dinobryon colonies that week. 2.3 Station II Phytoplankton Samples One of two 1 m replicates from Station II phytoplankton samples was randomly chosen for each week of March and A p r i l . Dinobryon colonies were ennumerated and measured as described in Chapter II; 3.2.2 & 3.3. Only one replicate was analyzed, as analysis of the data for Station I showed no s i g n i f i c a n t difference between replicates for estimates of colony size (App. T). Unlike the analyses of Station I samples though, colonies which e n t i r e l y lacked c e l l s were also enumerated and 93 the number of l o r i c a s per colony counted. 3. RESULTS 3.1 Gut Analysis Dinobryon l o r i c a s were observed in a l l zooplankton species examined, on a l l dates. Even in the smallest of these examined, B. coregoni, l o r i c a numbers ranged from from none to so many that they packed the entire digestive tract (Fig. 29; App. U). In most cases, l o r i c a s were concentrated in the foregut and near the anus. The q u a l i t a t i v e nature of the method precludes further comment. 3.2 Colony Size Frequency Distributions The drop in mean colony size of D. cyl i n d r icum during the f i r s t pulse (week 1 March) i s accompanied by the disappearance of large colonies (Fig. 30). The increase in colony size in the subsequent two weeks i s marked by the reappearance and increase of larger colonies, when this species makes up a r e l a t i v e l y small proportion of a l l Dinobryon colonies present (Fig. 32). In the month of A p r i l colony size again declines with the elimination of larger colonies (Fig. 30) as p. cylindricum makes up an increasing proportion of the t o t a l Dinobryon biomass (Fig. 32). The elimination of large colonies also accompanies the 94 decline in mean colony size of D. divergens (Fig. 31), and i s most conspicuous during the t h i r d and fourth weeks of March. Following week 3 of March, the maximum colony sizes of both species were always similar and declined together, even though both their mean colony sizes and populations d i f f e r e d in size and pattern of change (Figs. 30, 31,32). 95 F i g u r e 29 - Zooplankton Gut A n a l y s i s Examples D i a c y l o p s thomasi A,B. Daphnia l o n g i s p i n a C,D. Bosmina c o r e q o n i E,F. Arrows p o i n t t o l o r i c a s . M a g n i f i c a t A,B,C 250X; D,E 400X; F 1000X. 96 4 8 4 2 £ 3 6 J 3 0 o (_> = 2 4 < 1 2 -6 -4 8 -4 2 -£ 3 6 -I 3 0 -o = 2 4 -< o 1 8 -1 2 -6 -1 - F e b n = 1 5 5 i i i i 1 i I l l l i i l l 2 - F e b n : 1 6 6 * e 3 3 6 -c • o 3 0 -o -2 4 -< -1 8 --1 2 -6 -I I I I ! I I 3 - F e b n = 1 0 6 I I I I I I I I l I I l | 4 8 -4 2 ' 2 3 6 -J 3 0 ' o J 2 4 -•5 >eH 12 6H 4 - F e b n = 8 7 •R-R-i i i i i1 1 0 2 0 3 0 4 0 5 0 6 0 7 0 # L o r i c a s p e r C o l o n y 1 - M o r n . 1 6 6 3 - M a r n = 1 5 6 I I I I I I I I I I I I i 1 0 2 0 3 0 4 0 5 0 6 0 7 0 *f L o r i c a s p e r C o l o n y 4 8 4 2 HH 30-1 2 4 1 8 -1 2 -6 -1 - A p r n : 1 6 3 I I I I ! TT 4 8 ' 4 2 ' 3 6 ' 3 0 ' 2 4 -1 8 -1 2 -6 -4 8 -4 2 -3 6 -3 0 -2 4 -I B -1 2 ' 6 -4 8 -4 2 " 3 6 -3 0 -2 4 -le-tt-er n_ 2 - A p r 1 ^ — n = 1 8 5 i i i i I i n 3 - A p r n = 1 8 6 TT n i i i i i 4 - A p r n = 1 3 3 i i 1 1 n i i i i i i i i 1 0 2 0 3 0 4 0 5 0 6 0 7 0 *t L o r i c a s p e r C o l o n y F i g u r e 30 - D. c y l i n d r i c u m Colony S i z e Frequency D i s t r i b u t i o n s • From the p o o l e d d a t a from 1, 2, & 3 m, week 1 of Fe b r u a r y t h r o u g h week 4 of A p r i l 1983 - Como Lake. 97 1 - A p r n = 1 8 6 i i i i I i I I I I I I I . 10 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 W L o r i c a s p e r C o l o n y I I I I I 4 8 ui-3 6 -3 0 -2U 1 8 12 6 4 - A p r n = 1 3 3 i i i i i I i I i i I l l I I l I I l I 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 0 1 0 0 # L o r i c a s p e r C o l o n y Figure 31 - p. divergens Colony Size Frequency Distributions From the pooled data from 1, 2, & 3 m, week 1 of March through week 4 of A p r i l 1983 - Como Lake. 98 Figure 32 - Combined Size Class Frequency Di s t r i b u t i o n s From the pooled data of 1, 2, & 3m, week 1 of March through week 4 of A p r i l 1983 - Como Lake. A l l colonies combined ( • ). The proportion made up by D. cylindricum ( ) # 99 3.3 Stat ion II Population Dynamics The patterns of population changes in Station II were similar to those of Station I with two exceptions (Fig. 32; App. V). The population of D. divergens dropped during week three of March and the second pulse of p. cylindricum began to f a l l one week e a r l i e r in Station II than in Station I. Additionally, the colony densities of both species in Station II were lower after the f i r s t week of March than they are in Stat ion I. 3.4 Stat ion II Colony Size Dynamics Again the patterns of colony size v a r i a t i o n in Station II are similar to Station I with exceptions (Fig. 32; App. V). The colony size of p. divergens was lower during week one of March in Station II. The colony size of both species in the t h i r d week of March also was smaller in Station II at the time when the population of p. divergens also declined, in contrast to Station I. F i n a l l y , the mean colony s i z e of p. cylindr icum dropped with the population of i t s second pulse, one week sooner in Station 11. 100 uo 120j 1001 80 60 j *oH 20 I i rP'T i r 30-i 26 1*22-1 § 184 i D | I I I I | I I I UO-120-_ 100-\ 80 * 1 60-J 40W 20 n i i n i i j i mar ' ' UO 120 100 80 60 40' 20-30-26-22-18-U -10-6-2-B i I i i | i i uo 120 100 80H 60 40H 20 I I I | I I I | H apr I I I | I I I mar apr I I M I I I I mar 1 apr Figure 33 - Station II Results Colony densites A & B. Colony Size D & E. # Single Empty Loricas G & H. C & F are correponding results from Station I 1 M. D. cylindricum ( ) p. divergens (- ). 101 3.5 Stat ion II Single Empty Loricas Coinciding with the decline in the colony size and population of each species, there was a marked increase in the numbers of single empty l o r i c a s in the water (Fig. 32). The numbers of single empty l o r i c a s i n i t i a l l y increased as each population began to grow. During the f i r s t week of A p r i l , when the populations of both species expanded rapidly with increased l i g h t l e v e l s and water temperature, their numbers decreased. Following the peak densities of single empty l o r i c a s , their numbers f e l l as the populations of l i v i n g colonies declined further. M Loricas Per Empty Colony DATE SPP 1 2 3 4 5 6 7 8 9 10 1 1 12 March 3 C D 1 .5 0. 1 0.08 - 0.05 - - - - - - -March 17 C D 107.35 5 . 10 3 . 75 0. 28 1 . 70 0.17 O. 73 0.05 0. 48 0.03 0.13 0.08 0.08 0.08 0.03 0.05 -March 24 C D 42 . 28 13. 23 0. 55 0. 20 0. 20 0.05 0.08 0.08 - 0.03 0.03 - - 0.03 - -March 31 C D O. 55 4 . 65 0.08 0. 15 0 0 5 0.13 0. 10 0.05 0.03 0.05 ------Apr i1 7 C D 1 .95 20. 35 0. 23 0. 55 0. 58 0. 10 0.18 - - 0.05 - - - -April 14 C D 21 .43 73 .05 0. 58 0. 23 0. 25 0.90 0. 10 0.45 0.13 0.03 0.08 0.03 - -- - -A p r i l 21 C D 6 . 58 13.75 0.35 0. 23 O. 15 0. 18 0.15 0. 15 0.05 0.15 0.05 0.15 0.05 0.03 0.03 -0.08 - 0.03 Table VIII - Abundances of single empty l o r i c a s and empty colonies (#/ml) From Station II; 1 m - week 1 of March through week 3 of A p r i l 1983. D. cylindricum - C; D. divergens - D Empty colonies, composed of two or more l o r i c a s , were also present in the water, but were considerably outnumbered by the 102 single empty l o r i c a s (Table VIII). Their numbers also increased but only at the end of population declines. 4. DISCUSSION The assumptions underlying the proposed hypothesis are supported by the further analysis of Station I data. Dinobryon colonies were being consumed by the zooplankton. Larger colonies were being eliminated when the mean colony size of a population pulse declined. The maximum colony sizes of the two species were similar when they co-occurred even though their mean colony sizes were very d i f f e r e n t . This lends support to the assumption that Diacyclops thomasi was s e l e c t i v e l y grazing on the larger colonies and therefore was instrumental in colony size declines. But colony size modification i s not l i k e l y to be limited just to thi s species. A major difference between stations in zooplankton community structure i s the marked increase of Daphnia longispina in Station II over that of Station I, between the f i r s t and f i f t h week of March. Corresponding to thi s i s the decline in the population of D. divergens and the lower mean colony sizes of both species in the t h i r d week of March (Fig. 32). It would seem that Daphnia longispina may also be capable of modifying Dinobryon colony size and affe c t i n g population densites i f the decrease of the Dinobryon densities in Station II, after the f i r s t week of March, i s considered. 103 From the analysis of Station II samples there is further evidence that supports the assumptions of the new hypothesis. Large numbers of single empty l o r i c a s appear in the water column immediately after the decline of a l l Dinobryon pulses. Since l o r i c a s are not digested by the zooplankton, increases in the numbers of single empty l o r i c a s is probably indicative of increased grazing by zooplankton. Similar relationships between grazing and the presence of diatom frustules in the water column have been observed previously (Bailey-Watts & Lund 1973, Bailey-Watts I976a,b). This increase in the number of single empty l o r i c a s coincides with increases in the concentration and v a r i a b i l i t y of soluble reactive phosphate (Fig. 10). Since zooplankton grazing regenerates soluble reactive phosphate (Rigler 1961, Barlow & Bishop 1965, Peters & Lean 1973, Lehman 1980a,b), an increase in the patchiness and in the concentration of t h i s nutrient would be expected during periods of intense graz ing. The increase in the large empty colonies should not be ignored. Even though their numbers are very small and their occurrence takes place at the end of each pulse, the increased loss in c e l l s from colonies must be included in the consideration of population and colony size declines, even i f only at the very end of a pulse (Chapter 4; Section 3). 1 04 VI. SUMMARY AND CONCLUSIONS In th i s study i t was demonstrated that the blooms of two common vernal species of Dinobryon take place in the face of an expanding zooplankton community. It was also argued that changes in colony sizes and population densities of Dinobryon may be attributed to grazing and d i f f e r e n t i a l grazing losses afforded by differences in colony morphology. A f i r s t pulse of D. cylindricum declined with the i n i t i a l increase of larger zooplankton grazers. However, this population again increased three weeks later while the second species D. divergens predominated. This larger population of D. divergens declined f i r s t . One week later the smaller pulse of D. cylindricum declined, as the biomass of the zooplankton community continued to increase. The mean size of Dinobryon colonies f e l l during the course of each pulse. With the onset of a decline in population de n s i t i e s , the drop in mean colony size was sharper, and coincided with a marked increase in the numbers of single empty l o r i c a s , as well as an increase in the v a r i a b l i t y and mean concentration of soluble reactive phosphate. As colony size declined, there was a concommitant elimination of large colonies from each population. When both species co-occurred, their maximum colony sizes were the same, in spite of the fact that t h e i r mean colony sizes d i f f e r e d markedly at times. The declines of p. cylndricum pulses coincided with 1 05 increases in the abundances of copepodite and adult stages of cyclopoid copepods. S t a b i l i z a t i o n in the numbers of these zooplankton coincided with the s t a b i l i z a t i o n of colony size for the bulk of both species populations in the upper portions of the lake. With increased densities of large zooplankton grazers (as observed in Station II) both the colony size and population densities were depressed. These observations suggest that zooplankton grazers, p a r t i c u l a r l y the larger cladoceran and later stages of cyclopoid copepods, are important factors in determining the dynamics of colony size and population change of these two vernal species of Dinobryon. Differences in the dynamics of colony size and population changes between the two species, in the face of the same zooplankton assemblage, may be a function of species s p e c i f i c changes in colony morphology. For colonies with i d e n t i c a l numbers of l o r i c a s , those of D. divergens are wider and shorter than those of D. cylindricum. As the width of captured p a r t i c l e s determines their i n g e s t a b i l i t y by zooplankton, the wider colonies of D. divergens would be less readily ingested and more l i k e l y to be broken apart in the process. Enhanced fragmentation of colonies during encounters with larger zooplankton would therefore reduce grazing losses. In t h i s way the population of D. divergens would continue to increase in the face of zooplankton grazers where as that of D. cylindricum would suffer greater losses and possibly decline as a r e s u l t . 1 06 Predictable increases in the temperature and insolation each spring results in the annual spring diatom bloom in many temperate lakes. As a result of the greater a v a i l a b i l t y of prey and r i s i n g lake temperatures, zooplankton numbers increase. Therefore when the statospores of Dinobryon species germinate, either during or following the decline of the diatom bloom, they generally face an already developed or developing community of zooplankton grazers. For a Dinobryon population to increase under these conditions, i t must be able to innundate the grazers with c e l l s and therefore o u t s t r i p the grazing rate. Simply having a high reproductive rate alone would be i n s u f f i c i e n t to overcome the immediate grazing pressure of an established zooplankton community. Recruitment from a large resting spore population would be esse n t i a l i f Dinobryon were to overcome these grazers. However, the existence of an extensive statospore population i s contingent on the previous development of large vegetative populations and s u f f i c i e n t time for their formation. Single l o r i c a t e c e l l s of Dinobryon are susceptible to most zooplankton grazers because of their r e l a t i v e l y small width. A spring bloom of single c e l l s , or even small colonies, would be vulnerable to grazing, regardless of the zooplankton community composition. This would jeopardize the production of statospores and therefore the future perennation of the population. On the other hand, formation of larger colonies which, at least i n i t i a l l y , minimizes grazing losses and permits the growth of a sizable Dinobryon population, would ensure the 107 formation of s u f f i c i e n t numbers of statospores to i n i t i a t e subsequent blooms. The timing of statospore germination i s a function of the increasing insolation levels in the lake (Sheath et a_l. 1975). But the development of the grazing community in spring is a complex function of the a v a i l a b i l i t y and germination of resting eggs and/or overwintering individuals, the size of the vernal bloom of phytoplankton, predation and lake temperature (Allen 1976). The size and composition of the zooplankton community at the time of Dinobryon germination would be uncertain. A general defence would be required to minimize grazing losses to a broad range of possible zooplankton grazers, and thereby ensure adequate production of statospores. The i n i t i a l formation of large l o r i c a t e colonies by Dinobryon would afford such a generalized defence. Such colonies would minimize losses to both small and large zooplankton grazers by being s u f f i c i e n t l y large to i n h i b i t ingestion and by breaking up respectively. Regardless of the zooplankton community composition, germinating populations would be able to increase. As such, colony formation would not s t r i c t l y defend against zooplankton grazers but rather minimize inevitable losses, and so, buy time for the formation of statospores. Since D. divergens appears l a t e r in the spring than D. cylindricum (Munch 1972, Sandgren 1978, this study), there i s an increased pr o b a b i l i t y that- i t s population w i l l face a community composed of larger, slower reproducing zooplankton 108 grazers. Wider colonies that were more readily broken up during grazing would therefore be more advantageous. For the e a r l i e r blooming p. cylindricum, wider colonies would not be as important, as i t is more l i k e l y to encounter the smaller rapidly reproducing zooplankton. Increased size r e l a t i v e to these smaller grazers would be s u f f i c i e n t to minimize grazing. Dinobryon colony morphology is dictated by l o r i c a morphology which i t s e l f i s under s t r i c t genetic control. I n t e r s p e c i f i c differences in l o r i c a , and colony morphology, may represent differences in strategies which are directed at taking advantage of the p a r t i c u l a r conditions that occur in temperate lakes following the vernal diatom bloom, but prior to s t r a t i f i c a t i o n . In setting forth t h i s explanation for the results of this study, the intention here is not to assert that zooplankton grazing is the sole causal factor responsible for the population dynamics of these two Dinobryon species. Indeed the data suggest that other factors must also be considered. For example, the sudden decline in the large population of D. divergens may have been i n i t i a t e d by depressed nutrient lev e l s induced temporarily by the bloom, which constrained further growth, but which were not evident in weekly sampling. Also, towards the end of pulses, the elimination of large colonies and decline in densities may have been augmented by the losses of c e l l s from colonies. 1 09 What is being suggested here i s that zooplankton grazing played an important part in determining the colony and population dynamics of these two Dinobryon species, in this rather small lake in spring. Although further generalizations would be tempting, the extrapolation of t h i s explanation to other data on Dinobryon from other lakes at other times of the year, must be done with extreme caution. To extend these ideas to other c o l o n i a l phytoplankton species would be tenuous, because the results may r e f l e c t the l o r i c a based nature of Dinobryon colonies. Nevertheless, the phytoplankton assemblages ch a r a c t e r i s t i c of early s t r a t i f i c a t i o n are predominantly c o l o n i a l (Munch 1972, Sandgren 1978, Reynolds 1980). The p o s s i b i l i t i e s of extrapolating these results, and the hypothesis generated from them, should therefore be explored. The explanation of Dinobryon colony size and population dynamics offered here, and the hypothesis drawn from i t , serve as the background for further research into the dynamics of Dinobryon populations s p e c i f i c a l l y , and the interactions of c o l o n i a l phytoplankton with their zooplankton grazers in general. It i s not recomended that a similar in depth study be undertaken again because of the cost of time and e f f o r t involved. More f r u i t f u l results might now be best approached through laboratory or f i e l d manipulations. Such experiments might involve the manipulation of Dinobryon colony size and subjecting d i f f e r e n t sized colonies to a broad spectrum of grazers. As such, the hypothesis generated by t h i s thesis might be tested and further expanded upon. 1 1 0 BIBLIOGRAPHY 1. Ahlstrom, E.H. 1937. 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Syst. 13:349-72. 152. Underwood, A.J. 1981. Techniques of analysis of variance in experimental marine biology and ecology. Oceanogr. Mar. B i o l . Ann. Rev. 19:513-605. 153. Venrick 1 54. E.L. 1978a. The implications of subsampling. pp 75-87. I_n A. Sournia (Ed), Phytoplankton Manual. UNESCO, Paris. 337pp. . 1978b. Sampling strategy. pp 7-16. I_n A, Sournia, (Ed), Phytoplankton Manual. UNESCO, Paris. 337pp. 155. Vogel, S. 1983. L i f e in Moving Fluids: the Physical Biology of Flow. Princeton University Press, Princeton, New Jersey. 352pp. 156. Vollenweider, R.A. 1974. A Manual on Methods for the Measurement of Primary Production in Aquatic Environments. 2nd. Ed. International B i o l o g i c a l Program Handbook #12, Blackwell S c i e n t i f i c Publications, Oxford. 225pp. 157. Walsby, A.E. & Reynolds, C.S. 1980. Sinking and f l o a t i n g . pp 371-412. In I. Morris (Ed.), The Phy s i o l o i g i c a l Ecology of Phytoplankton. Blackwell S c i e n t i f i c Publications, Oxford. 625pp. 158. Webster K.E. & R.H. inh i b i t i o n s f ilamentous 23:1238-45. Peters. 1978. Some size-dependent of larger cladoceran f i l t e r s in suspensions. Limnol. Oceanogr. 159. Wehr, J.D. 1979. Analysis of Patterns in Algal Community Structure in the North Alouette River Watershed, B r i t i s h Columbia. MSc. Thesis. University of B r i t i s h Columbia, Vancouver, Canada. 136pp. 160. Wetzel, R.G. 1975. Limnology. W.B. Saunders Co., Philadelphia. 743pp. 1 24 161. Wetzel, R.G. & G.E. Likens, 1979. Limnological Methods. Saunders Co., Philadelphia. 357pp. 162. Willen, E. 1976. A s i m p l i f i e d method of phytoplankton counting. Br. Phycol. J. 11:265-78. 163. Willen, E. & T. Willen, 1979. About freshwater phytoplankton p 297-300. I_n A. Sournia (Ed.), Phytoplankton Manual. UNESCO, Paris. 337pp. 164. Yates, F. 1960. Sampling Methods for Census and Surveys. Hafer Publishing Co., New York. 440pp. 125 APPENDIX A - EFFECT OF SAMPLING PUMP ON COLONY SIZE Univariate oneway ANOVAs for testing the e f f e c t s of the sampling pump on the colony size (#LPC) of D. cylindricum and D. divergens, are detailed here. Thirty-one colonies in a 10 ml aliquot from each of 5 samples, were randomly chosen and their l o r i c a s counted. Three of these samples were drawn by hand and two by pump from 0.75 m at Station II on 17 March 1983. The resultant data were log transformed to s a t i s f y the assumption of equal variances. The results show there was no s i g n i f i c a n t differences among the colony sizes of hand and pump drawn samples. RAW DATA UNIVARIATE 1-WAY ANOVA <1> SAMPLE:HAND*1*SPECIES:D.CYLN <2> SAMPLE:HAND*2*SPECIES:D.CYLN <3> SAMPLE:HAND*3* SPEC IES:D.CYLN <4> SAMPLE:PUMP*1'SPECIES:0.CYLN <S> SAMPLE:PUMP*2*SPECIES:D.CYLN ANALYSIS OF VARIANCE OF 3.LORICA* N" 154 OUT OF 154 SOURCE BETWEEN WITHIN TOTAL DF SUM OF SORS MEAN SOR F-STATISTIC SIGNIF 4 307.69 76.922 1.1915 .3169 149 9619.0 64.557 153 9926.7 (RANDOM EFFECTS STATISTICS) ETA« .1761 ETA-SOR- .0310 (VAR COMP" .40149 XVAR AMONG- .62) EQUALITY OF VARIANCES: DF• 4, 33289. F" 5.8823 <1> <2> <3> <4> <5> 30 31 31 31 31 MEAN 7.6333 6.9677 7.6452 8.2581 1 1 .000 VARIANCE STD DEV 154 8.3052 4S.06B 43.699 22.970 105 .06 105.33 64.880 6.7133 6.6105 4.7927 10.250 10.263 8.0548 UNIVARIATE 1-WAY ANOVA <1> SAMPLE:HAND*1*SPECIES:D.DIV <2> SAMPLE:HAND*2«SPECIES:0.DIV <3> SAMPLE:HAND*3*SPECIES:0.DIV <4> SAMPLE:PUMP*1'SPEC IES:D.DIV <S> SAMPLE:PUMP#2«SPECIES:D.DIV ANALYSIS OF VARIANCE OF 3.LORICA* N" 155 OUT OF 155 SOURCE DF SUM OF SORS MEAN SOR F-STATISTIC SIGNIF 1.4438 .2224 BETWEEN WITHIN TOTAL 4 1393.6 348.39 150 36196. 241.31 154 37590. (RANDOM EFFECTS STATISTICS) ETA. .1925 ETA-SOR" .0371 (VAR COMP- 3.4543 *VAR AMONG' 1.41) EQUALITY OF VARIANCES: OF* 4. 33750. F- .37849 STRATA N MEAN VARIANCE STD DEV < 1> 31 28.677 213.56 14 .614 <2> 31 27.645 267.50 16 .356 <3> 31 34.290 292.28 17 .096 <4> 31 32.710 235.48 15 345 <5> 31 26.548 197.72 14 .061 GRAND 155 29.974 244.09 15 .623 1 2 6 LOG TRANSFORMED DATA UNIVARIATE 1-WAY ANOVA <1> S A M P L E : H A N D * 1 » S P E C I E S : D . C Y L N <2> SAMPLE:HAND#2*SPECIES:D.CYLN <3> SAMPLE:HAND#3*SPECIES:D.CYLN <4> SAMPLE:PUMP#1*SPECIES:D.CYLN <5> SAMPLE:PUMP#2»SPECIES:D .CYLN ANALYSIS OF VARIANCE OF 1 0 . L O G . V 3 N- 154 OUT OF 154 SOURCE DF SUM OF SORS MEAN SQR F - S T A T I S T I C SIGNIF BETWEEN 4 .69012 .17253 1 6511 .1645 WITHIN 149 15 .570 .10450 TOTAL 153 16 .260 (RANDOM EFFECTS STATIST ICS) ETA= .2060 E T A - SQR= .0424 (VAR COMP= .22090 -2 %VAR AMONG- 2 EQUALITY OF VARIANCES : DF= 4 , 33289 F= 1 5294 .1906 STRATA N MEAN VARIANCE STD DEV <1> 30 . 74910 .11382 .33738 <2> 31 . 72812 .(85517 -1 .29243 <3> 31 .81218 .62197 -1 .24939 <4> 31 .72197 .14729 .38378 <5> 31 .89946 .11397 .33759 GRAND 154 . 78238 .10628 .3260O UNIVARIATE 1-WAY ANOVA <1> SAMPLE:HAND#1*SPECIES:D.D IV <2> SAMPLE:HAND#2*SPECIES:D.DIV <3> SAMPLE:HAND#3*SPECIES:D.D IV <4> SAMPLE:PUMP*1 * S P E C I E S : D . D I V <5> SAMPLE:PUMP#2*SPECIES:D.D IV ANALYSIS OF VARIANCE OF 1 0 . L 0 G . V 3 N= 155 OUT OF 155 SOURCE DF SUM OF SORS MEAN SOR F - S T A T I S T I C SIGNIF BETWEEN 4 .39577 .98942 -1 1.2640 .2867 WITHIN 150 11.742 .78277 -1 TOTAL 154 12.137 (RANDOM EFFECTS STATIST ICS) E T A * .1806 ETA -SQR= .0326 (VAR COMP«= .66660 -3 %VAR AMONG= .84) EOUALITY OF VARIANCES'. 0 F « 4 , 33750 F= .53051 .7133 STRATA N MEAN VARIANCE STD DEV <1> 31 1 3974 .59399 -1 .24372 <2> 31 1 3529 .94849 -1 .30798 <3> 31 1 4682 .71480 -1 .26736 <4> 31 1 4494 .74591 -1 .2731 1 <5> 31 1 341 1 .91065 -1 .30177 GRAND 155 1 4018 .78814 -1 .28074 127 APPENDIX B - TAXANOMIC IDENTIFICATION - SOURCES The sources used for a l l i d e n t i f i c a t i o n s are l i s t e d here. The references c i t e d are found in the bibliography. S P E C I E S S O U R C E S D i n o b r y o n c y l i n d r i c u m I m h o f A h l s t r o m 1 9 3 7 D i n o b r y o n d i v e r q e n s I m h o f A h l s t r o m 1 9 3 7 D i n o b r y o n b a v a r i c u m I m h o f A h l s t r o m 1 9 3 7 A s p l a n c h n a p r i o d o n t a G r o s s e E d m o n d s o n 1 9 5 9 B o s m i n a c o r e p j o n i B a i r d P e n n a k 1 9 5 3 ; B r o o k s 1 9 5 9 D i a c y c l o p s t h o m a s i P e n n a k 1 9 5 3 G u r n e y 1 9 3 3 D a p h n l a l o n g i s p i n a S a r s P e n n a k 1 9 5 3 ; B r o o k s 1 9 5 9 K e l l i c o t t i a b o s t o n i e n s i s R o u s s e l e t E d m o n d s o n 1 9 5 9 K e r a t e l l a c r a s s a A h l s t r o m A h l s t r o m 1 9 4 3 K e r a t e l l a q u a d r a t a M u l l e r A h l s t r o m 1 9 4 3 D i a p t o m u s s p . W e s t w o o d P e n n a k 1 9 5 3 F i l i n i a s p . B o r v d e S t . V i n c e n t E d m o n d s o n 1 9 5 9 H e x a r t h r a s p . S c h m a r d a E d m o n d s o n 1 9 5 9 L e c a n e s p . N i t z s c h E d m o n d s o n 1 9 5 9 P o l y a r t h r a s p . E h r e n b e r q E d m o n d s o n 1 9 5 9 T r i c h o c e r c a s p . B o r y d e S t . V i n c e n t E d m o n d s o n 1 9 5 9 1 28 APPENDIX C - DAILY MEAN/MAXIMUM TEMPERATURES AND HOURS OF BRIGHT SUNSHINE FOR THE COMO LAKE REGION These data were taken at the Vancouver International Airport ca. 25 km southwest of Como Lake. Although allowances must be made for the mountains to the north of the lake, these readings are representative of the meteorological conditions at the lake. Source; The Annual Meterorological Summary -Vancouver, 1983 (E.C. - A.E.S. 1983). Temperature readings are given in °C. D A Y M A X I M U M T E M P E R A T U R E J A N F E B M A R A P R 1 4 7 9 0 8 3 8 0 1 1 4 4 3 9 6 7 2 8 2 6 5 9 4 1 0 5 5 6 2 1 6 9 7 5 3 7 1 5 4 B 5 1 0 9 4 9 1 5 6 9 8 0 4 9 7 5 6 9 5 1 2 2 6 8 1 0 6 6 7 4 5 7 8 5 3 8 3 1 0 8 6 1 1 0 5 5 7 9 6 6 5 7 9 1 3 0 1 4 5 5 2 3 9 9 1 1 0 3 7 1 0 7 8 8 1 1 6 1 1 8 8 5 5 2 9 1 9 7 e 9 2 6 3 1 0 6 1 0 3 5 6 2 5 8 9 7 2 9 1 0 2 8 3 1 5 4 7 9 6 1 5 5 1 2 7 6 0 1 0 1 1 5 8 8 1 3 0 9 0 9 4 7 3 1 0 2 5 6 1 1 1 2 0 1 3 4 1 3 0 9 8 9 7 0 0 9 5 7 0 1 2 1 0 0 1 1 0 1 2 3 1 0 9 8 6 9 8 9 2 6 6 1 3 e 9 1 1 2 1 2 0 1 2 1 5 8 9 0 8 0 7 0 1 4 6 9 9 1 1 2 5 1 3 6 3 2 7 2 8 9 7 9 1 5 6 8 1 1 5 1 1 3 1 4 2 2 0 7 5 7 2 9 0 1 6 7 7 1 0 2 1 7 1 1 4 4 3 9 8 1 9 2 9 2 1 7 9 8 1 1 2 1 1 6 1 6 2 7 5 8 3 6 8 1 0 4 1 8 1 0 9 9 1 1 3 3 1 6 3 9 2 6 2 7 5 1 0 2 1 9 8 8 7 6 1 3 6 1 9 1 7 9 5 3 7 8 1 2 6 2 0 8 0 1 2 5 1 1 9 1 4 4 6 8 9 2 7 2 1 1 8 2 1 7 6 9 6 1 0 2 1 4 B 4 5 5 8 7 7 1 0 2 2 2 6 6 1 2 8 1 3 9 1 5 7 2 6 9 8 1 0 2 1 0 1 2 3 6 9 1 4 7 1 3 0 1 4 3 4 8 1 2 3 9 6 1 0 6 2 4 1 0 3 1 1 3 1 0 7 1 2 9 8 0 8 6 5 6 1 0 6 2 5 1 0 5 1 2 4 1 3 5 1 1 3 8 6 8 7 8 3 9 8 2 6 9 6 1 0 7 1 3 0 1 4 5 8 4 8 6 9 4 1 0 8 2 7 1 1 O 8 6 1 1 9 1 4 5 7 5 1 5 4 8 3 9 5 2 8 1 0 2 7 2 8 3 1 7 8 6 7 4 9 6 9 1 1 8 2 9 9 3 1 0 8 1 9 4 6 2 8 4 1 3 2 3 0 9 3 1 1 2 1 8 1 6 4 B 9 1 3 1 3 1 1 0 1 1 1 8 5 9 8 6 M E A N T E M P E R A T U R E J A N F E B M A R A P R D A Y B R I G H T S U N S H I N E ( h ) J A N F E B M A R A P R 1 0 0 7 3 0 5 0 0 2 0 0 7 7 2 3 4 9 3 0 0 6 4 0 5 6 9 4 0 0 7 1 2 4 1 0 7 5 3 7 6 9 0 3 1 0 1 6 0 0 0 0 2 6 1 6 7 0 0 3 7 0 2 8 1 8 2 0 1 3 0 0 9 0 9 0 0 0 1 2 5 0 6 1 0 O 0 0 0 1 4 1 8 1 1 3 2 0 0 8 0 7 3 1 2 3 1 0 0 2 2 1 1 2 1 3 6 7 1 5 0 7 1 2 1 1 4 6 4 0 0 6 3 1 2 4 1 5 3 8 2 1 8 5 1 2 4 1 6 0 1 1 8 9 7 1 2 7 1 7 0 0 0 6 9 7 1 2 0 1 8 0 0 1 3 9 0 1 1 7 1 9 0 0 0 0 1 0 2 1 1 0 2 0 0 7 4 2 8 1 1 0 2 1 4 8 6 4 0 0 1 1 6 2 2 3 6 0 0 8 2 2 1 2 3 0 O 0 0 1 9 3 5 2 4 0 2 1 2 7 2 0 0 2 5 0 0 1 4 7 1 0 0 2 6 0 0 2 6 0 5 7 8 2 7 0 8 7 8 5 0 1 2 8 2 8 3 7 0 0 0 0 9 6 2 9 O 0 0 5 1 2 7 3 0 1 1 2 6 1 1 9 3 1 5 9 1 6 129 APPENDIX D - IRRADIANCE DATA AND EXTINCTION COEFFICIENTS Irradiance data taken in the f i e l d are detailed here. Readings were taken in the a i r , 5 cm below the surface and at 0.5 m intervals to the lake bottom. The calculated extinction coefficents at three depths 1, 2, and 3 m, are also given. D A T E S T N A I R I R R A D I A N C E R E A D I N G S O i E / m V s e c ) S U R F 0 . 5 M 1 . 0 M 1 . 5 M 2 . O M 2 . 5 M 3 . O M E X T I N C T I O N C O E F F I C I E N T S 1 M 2 M 3 M J A N 6 1 4 0 0 2 2 0 6 6 4 3 2 3 1 5 8 5 1 . 6 3 2 4 2 . 6 8 5 6 3 7 8 4 2 2 2 9 0 1 7 0 5 0 2 5 1 5 1 0 6 4 1 . 9 1 6 9 2 . 8 3 3 2 3 7 4 9 5 1 3 1 2 1 5 O 1 6 2 5 4 0 0 2 2 0 1 4 8 5 9 3 5 0 1 . 9 9 9 6 3 . 3 1 5 7 --2 2 9 0 0 2 5 0 0 6 3 5 3 2 0 1 7 0 9 3 5 4 3 2 2 . 0 5 5 7 3 . 2 9 1 4 4 3 5 8 3 2 0 1 9 5 0 6 2 5 2 8 0 1 5 0 9 0 5 2 3 1 1 9 1 . 4 2 7 1 2 4 8 6 5 3 4 9 3 3 2 2 1 2 5 1 5 5 0 8 1 5 3 9 0 2 1 0 1 1 6 6 5 4 0 1 . 3 7 9 9 2 . 5 9 2 4 3 6 5 7 1 2 7 1 8 2 0 4 6 0 2 3 0 1 1 8 6 4 4 1 2 5 1 6 1 . 3 6 0 5 2 . 4 1 7 7 3 3 5 8 6 2 1 5 0 0 9 1 0 4 3 0 2 2 0 1 2 5 7 8 4 6 2 8 1 . 4 1 9 8 2 . 4 5 6 7 3 4 8 1 2 F E B 3 1 2 1 0 0 1 7 5 0 6 6 0 3 1 0 1 6 5 9 7 5 7 3 4 1 . 7 3 0 8 2 . 8 9 2 7 3 9 4 1 0 2 3 3 8 0 2 8 7 0 1 3 0 0 6 0 0 3 1 0 1 9 0 1 0 5 6 2 1 . 5 6 5 1 2 . 7 1 5 0 3 8 3 4 9 1 0 1 2 6 5 1 5 5 6 4 3 2 1 8 1 1 7 5 1 . 5 7 7 7 2 . 6 4 5 5 3 4 3 4 0 2 1 3 5 0 2 6 0 1 1 0 5 2 2 9 1 8 1 1 7 1 . 6 0 9 4 2 . 6 7 0 3 3 6 1 4 8 1 7 1 3 0 O 2 0 0 9 3 5 5 3 0 1 8 1 0 6 1 . 2 9 1 0 2 . 4 0 7 9 3 5 0 6 6 2 1 9 0 0 1 3 0 0 5 6 0 3 0 0 1 7 0 9 7 5 6 3 2 1 . 4 6 6 3 2 . 5 9 5 4 3 7 0 4 4 2 4 1 1 9 5 1 0 6 5 2 2 7 1 6 1 0 6 5 1 . 3 6 7 6 2 . 3 6 0 9 3 0 5 4 0 2 6 8 0 3 9 0 1 9 0 9 9 5 6 3 8 2 5 1 6 1 . 3 7 1 0 2 . 3 2 8 6 3 1 9 3 6 M A R 3 1 7 5 0 3 7 0 1 6 0 9 0 5 3 3 4 2 2 1 4 1 . 4 1 3 7 2 3 8 7 1 3 2 7 4 4 2 7 8 0 4 1 0 1 9 0 1 1 0 6 8 4 3 2 8 1 8 1 . 3 1 5 7 2 . 2 5 5 0 3 1 2 5 8 1 0 1 O •-1 7 dL 1 3 1 0 0 2 0 0 0 6 5 0 3 1 0 1 5 7 8 3 4 4 2 7 1 . 8 6 4 3 3 1 8 2 1 4 3 0 5 1 2 4 4 0 O 3 4 0 0 1 4 3 0 6 4 0 3 3 O 1 8 3 9 4 4 6 1 . 6 7 0 1 2 9 2 2 0 4 3 0 2 9 2 4 1 2 5 5 0 1 6 1 0 7 7 0 3 4 0 1 8 7 1 0 7 5 9 4 1 1 . 5 5 5 0 2 . 7 1 1 2 3 6 7 0 4 2 5 5 0 0 3 6 0 0 1 5 2 0 8 3 0 4 7 0 2 7 0 1 4 5 8 7 1 . 4 6 7 3 2 5 9 0 3 3 7 2 2 8 3 1 1 1 1 5 0 6 1 0 2 4 9 1 0 5 5 9 3 4 2 0 1 0 1 . 7 5 9 5 2 8 8 7 1 4 1 1 0 9 2 2 6 0 0 1 3 0 0 4 5 0 1 7 2 8 8 5 2 3 0 2 8 2 . 0 2 2 6 3 2 1 8 9 3 8 3 7 9 A P R 7 1 3 9 0 0 2 1 0 0 9 3 0 4 5 0 2 7 0 1 6 0 1 0 0 6 0 1 . 5 4 0 4 2 . 5 7 5 4 3 5 5 5 3 2 2 8 2 0 1 5 0 0 6 7 0 3 5 0 2 0 5 1 1 5 6 7 3 7 1 . 4 5 5 3 2 5 6 8 3 3 7 0 2 3 1 4 1 6 5 0 0 3 9 0 0 2 0 0 0 9 5 0 5 5 0 2 9 3 1 4 5 7 4 1 . 4 1 2 3 2 5 8 8 6 3 9 6 4 7 2 7 3 0 0 4 8 0 0 2 4 0 0 1 3 0 O 7 4 0 4 0 0 2 2 0 1 1 8 1 . 3 0 6 3 2 4 8 4 9 3 7 0 5 7 2 1 1 2 9 0 O 1 1 0 0 5 0 0 2 9 0 8 8 5 3 3 0 2 7 1 . 3 3 3 2 3 0 3 2 8 3 7 0 7 2 2 5 8 0 O 2 1 5 0 9 9 O 5 0 0 2 9 9 1 6 3 9 0 5 2 1 . 4 5 8 6 2 5 7 9 5 3 7 2 2 0 2 8 1 5 2 0 3 0 1 1 4 5 6 5 3 0 1 8 1 0 5 1 . 5 3 2 7 2 8 1 6 7 4 0 9 7 7 2 1 4 5 0 7 7 0 3 3 0 1 8 0 9 2 5 4 3 0 1 6 1 . 4 5 3 4 2 6 5 7 4 3 8 7 3 8 M A Y 5 -- -- --1 1 1 3 7 0 o 2 7 5 o 1 0 4 0 3 9 0 1 7 5 7 5 3 4 1 3 1 . 9 5 3 2 3 6 0 1 9 5 3 5 4 4 2 4 5 0 0 4 1 5 0 1 4 9 0 6 2 0 2 7 0 1 2 0 5 3 2 2 1 . 9 0 1 1 3 5 4 3 4 5 2 3 9 8 1 9 1 3 8 0 0 2 7 5 0 9 9 0 3 7 0 1 6 0 6 4 2 6 9 2 . 0 0 5 9 3 7 6 0 5 5 7 2 2 1 2 2 2 0 0 1 4 3 0 5 2 0 2 2 5 1 0 5 4 6 2 1 8 1 . 8 4 9 3 3 4 3 6 8 5 1 8 6 0 1 30 APPENDIX E - SOLUBLE REACTIVE PHOSPHATE CONCENTRATIONS Weekly soluble reactive phosphate concentrations are detailed here for 1, 2, 3 m at Stations I & I I . Weekly mean concentrations for a l l depths at each station and for both stations combined are also given. D A T E S O L U B L E R E A C T I V E P H O S P H A T E C O N C E N T R A T I O N S ( ^ t q / L ) S T A T I O N I S T A T I O N I I M E A N S J m 2m 3 m J J D 2 m 3 m S T N 1 S T N I_I S T N I / I _ I J A N 6 2 . 4 5 2 2 3 1 . 2 1 2 1 . 5 3 3 1 3 2 4 1 3 3 . 6 2 5 2 3 2 . 5 2 3 1 . 8 2 3 2 2 2 . 5 2 0 2 . 9 2 9 2 1 2 . 4 2 4 2 4 2 4 2 4 2 4 2 7 2 . 4 2 5 1 8 1 . 8 2 4 2 4 2 2 2 2 2 . 2 F E B 3 2 . 1 1 8 2 5 2 . 1 2 4 2 4 2 1 2 3 2 2 1 0 3 . 0 3 2 3 . 0 3 0 4 2 3 1 3 4 3 . 3 1 7 2 . 4 4 5 1 8 1 . 8 2 6 2 6 3 0 2 3 2 . 6 2 4 3 . 0 1 2 2 4 3 . 3 1 4 1 4 2 2 2 0 2 . 2 M A R 3 3 0 1 8 3 . 1 1 8 1 9 2 4 2 3 2 . 3 1 0 1 7 4 . 8 8 8 6 5 3 . 6 2 4 1 . 2 6 7 2 4 4 . 6 2 4 3 . 0 2 4 9 1 0 . 9 3 0 1 2 2 7 1 7 2 . 8 3 1 1 . 1 1 2 0 8 2 . 1 1 2 1 . 5 1 0 1 6 1 . 3 A P R 7 1 . 0 0 9 1 8 1 . 2 1 8 1 . 9 1 2 1 6 1 . 4 1 4 2 . 5 5 9 4 1 2 . 5 2 . 4 4 2 2 5 3 . 5 2 1 2 . 4 2 5 1 . 8 1 8 2 0 2 5 1 9 2 . 1 2 8 1 . 7 3 0 2 3 2 . 4 3 0 3 . 0 2 3 2 8 2 . 6 M A Y 5 1 1 1 . 3 2 4 1 . 8 3 3 2 . 1 1 9 2 4 2 . 2 1 9 2 . 2 2 4 2 4 1 . 2 1 8 1 9 2 1 1 6 1 9 D E P T H 2 . 3 3 1 2 9 2 . 1 2 2 2 . 1 2 8 2 2 2 . 5 M E A N 131 APPENDIX F - CELL VOLUME ANALYSIS The results for the univariate oneway ANOVA on the calculated c e l l volumes of D. cylindricum (March 3rd, A p r i l 7th) and D. divergens (March 17th, and A p r i l 7th) are detailed here. The test for equality of variances between samples was si g n i f i c a n t only at the 0.06 l e v e l . Therefore the analysis was also done on log transformed data, which better met this assumption. The results in both analyses indicate that there were no s i g n i f i c a n t differences between the c e l l volumes of a l l four samples. U N I V A R I A T E 1 - W A Y A N O V A A N A L Y S I S O F V A R I A N C E O F 5 . T R U E V O L N = 3 0 0 O U T O F 3 0 0 S O U R C E D F S U M O F S O R S M E A N S O R F - S T A T I S T I C S I G N I F 1 . 6 8 6 7 . 1 6 9 9 B E T W E E N W I T H I N T O T A L 3 2 4 7 1 5 . 8 2 3 8 . 2 2 9 6 . 1 4 4 5 7 + 7 4 8 8 4 . 2 2 9 9 . 1 4 7 0 4 + 7 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 1 2 9 6 E T A - S Q R = . 0 1 6 8 ( V A R C O M P = 4 6 . 3 7 1 % V A R A M 0 N G = . 9 4 ) E Q U A L I T Y O F V A R I A N C E S : D F = 3 , . 1 2 3 2 0 + 6 F = 2 . 3 9 8 2 . 0 6 6 0 D A T E N M E A N V A R I A N C E S T D D E V M A R 3 9 9 1 9 5 . 2 9 4 1 8 0 . 6 6 4 . 6 5 7 M A R 1 7 1 0 O 1 9 4 . 1 6 5 1 6 4 . B 7 1 . . 8 6 7 A P R 7 5 0 2 0 1 . 6 2 7 0 5 7 . 3 8 4 . 0 0 8 A P R 7 5 1 1 7 2 . 9 2 3 5 7 7 . 7 5 9 . . 8 1 3 G R A N D 3 0 0 1 9 2 . 1 7 4 9 1 7 . 8 7 0 . . 1 2 7 U N I V A R I A T E 1 - W A Y A N O V A A N A L Y S I S O F V A R I A N C E O F 6 . L O G N = 3 0 0 O U T O F 3 0 0 S O U R C E D F S U M O F S O R S M E A N S O R F - S T A T I S T I C S I G N I F . 1 6 5 9 B E T W E E N W I T H I N T O T A L 3 . 1 2 7 8 2 . 4 2 6 0 8 - 1 1 . 7 0 5 8 2 9 6 7 . 3 9 3 7 . 2 4 9 7 9 - 1 2 9 9 7 . 5 2 1 5 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 1 3 0 4 E T A - S O R = . 0 1 7 0 ( V A R C O M P = . 2 4 3 7 3 - 3 % V A R A M O N G = . 9 7 ) E Q U A L I T Y O F V A R I A N C E S : D F = 3 , . 1 2 3 2 0 + 6 F = . 6 6 4 4 1 . 5 7 3 8 D A T E M A R 3 M A R 1 7 A P R 7 A P R 7 N 9 9 1 0 0 5 0 5 1 M E A N . 2 6 4 4 . 2 6 2 6 . 2 7 0 2 . 2 1 0 3 V A R I A N C E . 2 5 1 1 7 - 1 . 2 1 5 6 7 - 1 . 3 0 0 8 3 - 1 . 2 6 4 6 2 - 1 S T D D E V . 1 5 8 4 8 . 1 4 6 8 6 . 1 7 3 4 5 . 1 6 2 6 7 G R A N D 3 0 0 2 . 2 5 5 5 . 2 5 1 5 6 - 1 1 5 8 6 0 1 32 APPENDIX G - COLONY ABUNDANCES - D. CYLINDRICUM Colony abundances, their confidence intervals and standard errors are given here for each week at Station I, January to A p r i l 1983. The combined density estimate and standard error for a l l three depths are also given. Counts for each replicate sample were averaged to obtain the density estimates each week. Confidence i n t e r v a l s and standard errors were calculated from these density estimates as detailed in Lund et a l . 1958. Combined density estimates are the sum of the densities at a l l 3 depths each week. This sum, multiplied by a factor of 1000, gives an estimate of the to t a l number of colonies beneath 1 m2. The standard error of this sum was calculated as in Yates (1960). "N" represents the number of replicate samples enumerated. 85% CONFIDENCE TOTAL COMBINED PATE DEPTH NO/ L INTERVAL c N NO/IOcm' S E LOWER UPER LIMIT LIMIT JAN 6 1 5 0 . 1 32 6 3 2361 1 - 0 10.0 2 7426 5 0 1 32 6 1 561 2 JAN 13 1 5 0 . 1 32 6 1 56 1 1 2 12 5 2.6 4 2 2 500 2 27.5 3 3607 10 0 1.6 40 4 3 2361 2 JAN 20 1 17 5 5.0 51 5 2 B580 2 32 5 13.7 72 3 4 031 1 2 70 0 5 9174 20 0 6.3 5 1 3 1623 2 JAN 28 , 1 15 0 74 6 175 6 7 5629 2 142 5 96 .8 20B 3 8 4 10 2 325.0 12 7476 67 5 37.9 17 6 5 B095 2 FEB 3 1 410 0 326.1 51 7 14 3178 2 607 5 506.4 728 3 17 4284 2 1527.5 27 6 360 510 0 417.9 621 8 15 9687 2 FEB 10 1 52 5 456.4 6B 3 16 6208 2 625 0 52.3 747 3 17 677 2 1612.5 28 07 12 435 0 350 4 539 3 14 7479 2 FEB 17 1 293 0 2638.0 3260 0 54 1572 1 670 0 563.4 796 2 18 3030 2 3640.5 57 302 37 5 16.9 79 0 4 301 2 FEB 24 , 3175 0 2657 0 3790 0 56 347 1 12 5 80.6 184 6 7 8262 2 370.0 57 2057 72 5 41.6 123 B 6 0208 2 AIAP 3 1 593O0 0 595.3 62798 1172 1918 2 790  0 7063 7 B3 6 62 8490 2 7357 .5 190 207 2 5157 5 4B49.8 5484 6 50 7814 2 MAP 10 \ - 00 -MAR 17 1237 5 926.5 1647 9 24 8747 2 430 0 314.9 584 9 14 629 2 1947 5 31 2050 2S0 0 18S.6 410 7 1 1 832 2 MAR 24 475 0 3»5 0 TB7 5 15 4 1 10 3 37 5 190 0 S87 5 13 * a o 4 2 730 5 25 9326 0 0 0 0 1 MAR 31 1 1 195 0 •2 5 1BO0 0 34 438 2 1087 5 798.0 1476 3  3184 3 3107.5 39 4 179 B25 0 57.5 172 5 30 3101 2 APR 7 1 16725 0 1502 3 1B642 4 91 467 2 2650 0 2179 8 321B 5 36 405 2 19791.7 9  5683 4 16 7 275.4 625 14 438 3 APR 14 t 2190O 0 1916 B 24075 5 104 642 2 620  0 5463.1 7034 5 5 676 2 31575.0 125 6483 3475 0 2931.B 416 3 41 63 2 APR 21 1 17B7 5 1407.2 26 7 39 8957 3 525 0 4831.2 6316 4 52 5S95 2 1712.5 56 5262 40  0 3784.5 513 46 804 2 3APR 2B 1 65 0 36.1 14 5 709 2 2 132 5 B.7 1B6 5 B 1394 2 42  . 5 14534 3 25 0 16 0 303 9 10 606 2 1 33 APPENDIX H - COLONY ABUNDANCES - D. DIVERGENS Colony abundances, their confidence intervals and standard errors are given here for each week at Station I, January to A p r i l 1983. The combined density estimate and standard error for a l l three depths are also given. Counts for each replicate sample were averaged to obtain the density estimates each week. Confidence intervals and standard errors were calculated from these density estimates as detailed in Lund et a_l. 1 9 5 8 . Combined density estimates are the sum of the densities at a l l depths each week. This sum, multiplied by a factor of 1000, gives an estimate of the t o t a l number of colonies beneath 1 m2. The standard error of thi s sum was calculated as in Yates (i960). "N" represents the number of repl i c a t e samples enumerated. 85% CONFIDENCE TOTAL COMBINED DATE DEPTH NO/I INTERVAL E N NO/ 10cm' E . LOWER UPER LIMIT LIMIT JAN 6 1 O .2 24 1 0 1 - 0 0 . 0 3 0 .2 24 1 0 2 JAN 13 1 0 .2 24 1 0 2 2 0 .2 24 1 0 2 0. 0 3 O . 2 24 1 o 2 JAN 2 0 1 0 .2 24 1 0 2 2 O . 2 24 1 0 2 0 O 3 0 . 2 24 1 0 2 JAN 27 1 0 .2 24  0 2 2 0 .2 24 1 0 2 0 0 3 O .2 24 1 0 2 0 . FEB 3 1 0 .2 24  0 2 2 7 5 .7 36 6 1 9365 2 12.5 2 50O0 3 5 0 . 1 32 6 1 581 1 2 FEB 10 1 5 0 . 1 32 6 1 58 1 1 2 2 0 . 2 24 1 0 2 5.0 1 581 1 3 0 .2 24 1 0 2 FEB 17 1 O 0. 0 0 1 2 0 .2 24 1 0 2 0. 0 3 O .2 24 1 o 2 FEB 24 1 25 0. 162 0 5 0 0 0 0 1 2 O .2 24 1 0 2 25.0 5 OOOO 3 O . 2 24 1 0 2 MAR 3 1 20O 0 63. 1 50 6 10 0 0 0 0 2 2 25 0 0.0 162 0 3 5 3 5 5 2 247 . 5 1 1 1249 3 2  5 7.7 58 6 3 354 1 2 MAR 10 - 0 - 0 - -- 0 MAR 17 1 46B7 5 4051.1 542 1 648 4123 2 2 5 9 5 0 457.4 72 3 17 2482 2 5675.5 53 2565 3 390 0 281 .0 538 9 13 9642 3 MAR 24 1 16362 5 15143.9 17678 0 80 4503 2 2 15075 1*06.8 16340 2 •6 818 2 3596.5 129 859 3 149 0 KI.O 1363 0 13 8968 1 MAR 31 1 28E2 5 37232 7 30*89 0 120 1301 3 2 2170 O 20282 5 23205 0 104 163 3 •1375.0 201 714 3 306 12 5 28127 4 32594 3 124 1218 3 APR 7 1 15850 011203 2 10689 6 340 6761 3 2 32987 5 31242 .7 34B26 9 128 4280 3 160912 5 83 64B1 3 12075 10621.5 13723 7 7  7014 3 APR 14 1 43025 4020.4 46023 3 146 67 14 32 16025 14819.4 17327 5 8  5126 3 70187 5 187 3334 3 1137 5 1013B.2 1234 0 74 634 1 2 APR 21 1 10875 0867.8 1859 2 73 7394 2 2 B725 0 8793.4 10753 6 £9 7316 2 24212 .5 no 0284 3 3612 5 3O58.0 4265 1 42 500 2 APR 28 1 SO O 54.8 145 4 6 7082 2 2 15 0 74.6 175 6 7 5829 2 335.0 12 9432 3 130 0 6.7 193 5 a 0623 ' 2 1 34 APPENDIX I - CELL DENSITIES - D. CYLINDRICUM C e l l abundances, their confidence intervals and standard errors are given here for each week at Station I, January to A p r i l 1983. The combined density estimate and standard error for a l l three depths are also given. Combined density estimates are the sum of the densities at a l l 3 depths each week. This sum, multiplied by a factor of 1000 gives an estimate of the to t a l number of c e l l s beneath 1 m2. The standard error of this sum was calculated as in Yates (1960). "N" represents the number of replicate samples enumerated. DATE DEPTH • LPC •COLONIES MEAN •COLONIES S E . /•CELLS S. E. /ml • LOR / 1 0 C I H ' /10cm' JAN 6 1 B .OO 5 .0 2 9.00 10.0 2.74 90 0 24 .30 3 9 .00 5 .0 JAN 13 1 13 .00 5 .0 2 5 .00 12 .5 6.80 27.5 3.36 187.0 22 .85 3 5 .67 10 .0 JAN 20 1 12 .29 17 .5 2 8 .25 32 .5 9.41 70.0 5.91 658.7 55 .61 3 8 .63 20 .0 JAN 27 1 13 .03 1 15 .0 2 12 .21 142 .5 1 1 .92 325.0 12.75 3874.0 151 .20 3 9 .81 67 .5 FEB 3 1 12 .45 4 10 .0 2 14 .97 607 . 5 13.17 1527.5 27.64 20117.2 364 .02 3 12 .98 510 .0 FEB 10 1 13 .21 552 .5 2 13 . 42 625 .0 13 .40 1612.5 28.07 21607.5 376 . 14 3 13 .58 350 . 4 FEB 17 1 13 .06 2638 0 2 15 69 670 .0 14 .09 3640.5 57.33 51294.7 807 .78 3 8 .92 37 .5 FEB 24 1 16 .42 3175 .0 2 10 .83 122 5 13 . 10 3370.0 57.21 44147.0 749 .50 3 11 .74 72 5 MAR 3 1 15 42 59300 .0 2 14 69 7900 0 14 . 15 72357.5 190.21 1023858 6 2691 .50 3 12 . 32 5157 . 5 MAR 10 1 2 g - - - -MAR 17 1 7 29 1237 . 5 2 5. 60 430. 0 6.24 1947.5 31.21 10280 .4 197 . 75 3 5 46 280. 0 MAR 24 1 24 05 475 0 2 19 52 337. 5 21 .78 720.5 25 .93 15692.5 564 .76 3 O 189. 6 MAR 31 1 23. .53 1195 . O 2 25 68 1087. 5 24.70 3107.5 38.42 76755.3 948 .97 3 24 90 825. 0 APR 7 1 22. 24 16725. 0 2 18. 95 2650. 0 18.78 19791.7 BB 57 37168S. 1 1869 .92 3 14. 97 416. 7 APR 14 1 18. 21 21900. 0 2 14 . 95 6200. o 15. 18 31575.0 125.65 4 79308.5 1907 . 37 3 12. 39 3475. 0 APR 21 1 9 81 1787. 5 2 e . 35 5525. O 9.20 11712.5 56.53 107755.0 520 .08 3 9. 44 4400. 0 APR 2B 1 8. 08 65. 0 2 6. 96 132. S 7.02 422.5 14.53 2965 0 102 .00 3 6 63 225. 0 1 35 APPENDIX J - CELL DENSITIES - D. DIVERGENS C e l l abundances, their confidence intervals and standard errors are given here for each week at Station I, January to A p r i l 1983. The combined density estimate and standard error for a l l three depths are also given. Combined density estimates are the sum of the densities at a l l 3 depths each week. This sum, multiplied by a factor of 1000, gives an estimate of the to t a l number of colonies beneath 1 m2. The standard error of this sum was calculated as in Yates (1960). "N" represents the number of replicate samples enumerated. DATE DEPTH #LPC 'COLONIES MEAN 'COLONIES S.E 'CELLS S.E. /ml #LOR /lOCfll* /10cm' JAN 6 1 0 0. 0 2 0. 0. 0. 0. 0. 3 O 0. 0 JAN 13 1 O 0. 0 2 0 0. 0 0. 0. 0. 0. 0. 3 0 0. 0 JAN 20 1 0 0. 0 2 O 0. 0 0. 0. 0 0. 0. 3 0 0. 0 JAN 27 1 0 0. 0 2 O 0. 0 0. 0. o . 0. 0. 3 0 0. 0 FEB 3 1 0 - 0. 0 2 40 .00 7 . 5 29.80 12.5 2. 50 372 .5 74.5 3 14 .50 5. 0 FEB 10 1 19 .00 5. 0 2 O 0. 0 19.OO 5.0 1 . 58 95.0 30.02 3 0 0. 0 FEB 17 1 0 0. 0 2 O 0. 0 0. 0. 0. 0. 0. 3 0 0. 0 FEB 24 1 30 OO 25. 0 2 0 0. 0 30.00 25.0 5. 00 750.0 150.00 3 0 0. 0 MAR 3 1 21 .43 200. 0 2 36 OO 25 . 0 23. 18 247.5 1 1 . 12 5737.1 257.76 3 21 .50 22. 5 MAR 10 1 2 - - - -3 MAR 17 1 29. 26 4687 . 5 2 21 . 53 595. 0 21.61 5672.5 53. 26 123717.2 1161.6 3 14 . 40 390. 0 MAR 24 1 16 .73 16362. 5 2 19 98 15075 0 16.84 32586.5 129. 86 548756.7 2186.84 3 10 .77 1 149 0 MAR 31 1 17 .26 28862. 5 2 13 .45 21700 0 15.OS 81385.0 201 . 71 1224843.3 3035.74 3 14 .45 30812. 5 APR 7 1 17 03 115850. 0 2 13 OS 32987 5 13.36 160912.5 283. •5 2149791.0 3789 56 3 10 OO 12075 0 APR 14 1 10 47 43025. 0 2 9 .45 16025. 0 9.53 70187.5 187. 33 6688B6.9 1785.25 3 B 68 12075. 0 APR 21 1 8 .24 10875. 0 2 7 .39 9725. 0 7.26 24212.S 1 10. 03 175782.8 798.82 3 6 . 15 3612 . 5 APR 2B 1 6 .97 90 0 2 7 .69 1 15. 0 6.65 335.0 12. 94 2227.8 86 .05 3 5 .57 130. 0 1 36 APPENDIX K - ANALYSIS OF INTERSPECIFIC COLONY MORPHOLOGY DIFFERENCES Both the Students t-test and the Mann-Whitney U-test were used to test for i n t e r s p e c i f i c differences between the six colony variables measured on Pinobryon colonies. These six variables were; the number of l o r i c a s per colony (LORICA#), colony length (TOT.LEN), colony width (TOT.WID), the number of empty l o r i c a s per colony (EMPTY#), the number of statospores per colony (STATO#), and the number of l o r i c a s in the longest branch (LONG.BR). These variables were neither normally distributed nor were the variances between the two species homogeneous (except for colony length). The large sample size though, permits the use of the t-tests (Underwood 1981). Nevertheless, the non-parametric Mann-Whitney U-test was also done for comparison. The results of both analyses concur: there were s i g n i f i c a n t differences between the two species for a l l variables. Student's T-Tests T W O - S A M P L E T - T E S T S V A R I A B L E S P E C I E S D . C Y L N 8 . M E A N 1 4 . 0 8 5 L O R I C A * V A R 8 8 . 6 3 1 ( T O T A L = 3 2 9 3 ) N 2 0 5 5 . 9 5 0 0 C O N F . I N T . O N D I F F 1 2 . M E A N 1 6 0 . 8 7 T O T . L E N V A R 2 8 2 5 . 0 ( T O T A L = 3 2 9 3 ) N 2 0 5 5 . 9 5 0 0 C O N F . I N T . O N D I F F 1 3 . M E A N 6 1 . 6 2 2 T O T . W I D V A R 1 1 2 8 . 3 ( T O T A L = 3 2 9 3 ) N 2 0 5 5 . 9 5 0 0 C O N F . I N T . O N D I F F 9 . M E A N 2 . 4 3 1 6 E M P T Y * V A R 9 . 1 7 0 5 ( T 0 T A L = 3 2 9 3 ) N 2 0 5 5 . 9 5 0 0 C O N F . I N T . O N D I F F 1 0 . M E A N . 1 4 5 9 9 S T A T O * V A R . 5 5 2 8 8 ( T O T A L = 3 2 9 3 ) N 2 0 5 5 . 9 5 0 0 C O N F . I N T . O N D I F F 1 1 . M E A N 4 . 8 6 2 1 L O N G . B R V A R 2 . 4 4 7 6 ( T O T A L * 3 2 9 3 ) N 2 0 5 2 . 9 5 0 0 C O N F . I N T . O N D I F F D . D I V T E S T S T A T I S T I C D F S I G N I F 1 3 . 3 2 3 T = 2 . 0 7 7 9 3 2 9 1 . 0 3 7 8 1 2 9 . 2 9 F = 1 . 4 5 8 8 1 2 3 7 . 2 0 5 4 . O O O O 1 2 3 8 P R 0 B ( 1 S T M E A N > 2 N D | D A T A ) = . 9 7 6 3 ( U N E Q U A L V A R I A N C E S ) ' ( . 9 1 4 9 5 - 2 , 1 . 5 1 5 0 ) 1 3 6 . 8 5 T = 1 2 . 6 2 9 3 2 9 1 . 0 0 0 0 2 7 4 2 . 9 F* 1 . 0 2 9 9 2 0 5 4 , 1 2 3 7 . 2 8 2 9 1 2 3 8 P R 0 B ( 1 S T M E A N > 2 N D jDATA) = 1 . O O O O ( U N E Q U A L V A R I A N C E S ) ' ( 2 0 . 3 0 3 . 2 7 . 7 3 0 ) 6 7 . 6 2 7 T = - 4 . 5 3 6 1 3 2 9 0 . O O O O 1 7 2 7 . 2 F = 1 . 5 3 0 8 1 2 3 6 , 2 0 5 4 . O O O O 1 2 3 7 P R O B ( 1 S T M E A N < 2 N D j D A T A ) = 1 . O O O O ( U N E Q U A L V A R I A N C E S ) " ( - 8 . 7 3 8 7 . - 3 . 2 7 1 4 ) 2 . 9 1 7 5 T = - 4 . 7 8 6 7 3 2 9 0 . O O O O 5 . 9 4 1 4 F = 1 . 5 4 3 5 2 0 5 4 , 1 2 3 6 . 0 0 0 0 1 2 3 7 P R 0 B ( 1 S T M E A N < 2 N D jDATA ) = 1 . O O O O ( U N E Q U A L V A R I A N C E S ) - ( - . 6 7 4 5 7 . - . 2 9 7 2 5 ) - 1 . 2 5 7 6 7 T = - 1 2 . 4 3 0 3 2 9 1 . O O O O - 1 . 6 9 4 2 6 F = 1 2 . 5 5 7 1 2 3 7 , 2 0 5 4 O . 1 2 3 8 P R O B ( 1 S T M E A N < 2 N D jDATA) = 1 . O O O O ( U N E Q U A L V A R I A N C E S ) * ( - . 2 9 0 5 9 , - . 1 9 5 5 6 ) 4 . 5 7 5 6 T = 4 . 8 1 3 2 3 2 8 7 . O O O O 3 . 2 1 0 5 F = 1 . 3 1 1 7 1 2 3 6 , 2 0 5 1 . O O O O 1 2 3 7 P R O B ( 1 S T M E A N > 2 N D jD A T A ) * 1 . O O O O ( U N E Q U A L V A R I A N C E S ) = ( . 1 6 5 8 7 . . 4 0 7 1 3 ) 1 37 Mann-Whitney U-Tests TWO-SIMPLE COMPARISON TEST OF 8.LORICA* SIGNIF 11351 +7 MANN-WHITNEY U* MEDIAN TEST 0000 OOOO TEST OF 12.T0T.LEN SIGNIF .94670 *6 MANN-WHITNEY U* MEDIAN TEST OOOO OOOO SPECIES N AVG. RANK MEDIAN* 12 N< N> .000 N-SPECIES N AVG. RANK MEDIAN* 150.80 N< N> N= D.CYLN D.DIV 2055 1238 1713.642 1536.378 952 1009 693 497 94 48 D.CYLN D.DIV 2055 1238 1805.319 1384 200 871 747 1 160 459 24 32 TOTAL 3293 OUT OF 3293 TOTAL 3293 OUT OF 3293 TEST OF 13. TOT.WID SIGNIF TEST OF 9.EMPTY* SIGNIF MANN-WHITNEY U = MEDIAN TEST .11983 +7 .0059 .01 19 MANN-WH MEDIAN ITNEY U-TEST .10424 *7 OOOO .OOOO SPECIES N AVG. RANK MEDIAN* 58 N< N> 000 N= SPECIES N AVG. RANK MEDIAN= 2. N< N> OOOO N= D.CYLN D.DIV 2055 1237 1611.107 1705.298 1025 922 566 613 108 58 D.CYLN D.DIV 2055 1237 1535.255 1831.309 979 382 744 60O 332 255 TOTAL 3292 OUT OF 3293 TOTAL 3292 OUT OF 3293 TEST OF 10 STATO* SIGNIF TEST OF 11.LONG. BR SIGNIF MANN-WHITNEY U* MEDIAN TEST .11193 +7 OOOO 1 .0000 MANN-WHITNEY U* MEDIAN TEST . 1 1439 *7 . OOOO .0000 SPECIES N AVG RANK MEDIAN* 0. N< N> N* SPECIES N AVG. RANK MEDIAN* 5 N< N> . OOOO N* D.CYLN D.DIV 2055 1238 1572.674 1770.376 0 16 0 158 2039 1080 D.CYLN 0 .DIV 2052 1237 1706.036 1543.751 792 595 712 385 548 2S7 TOTAL 3293 OUT OF 3293 TOTAL 3289 OUT OF 3293 138 APPENDIX L - ANALYSIS OF MEASURED LORICA LENGTHS Int e r s p e c i f i c differences between d i r e c t l y measured l o r i c a -lengths were tested for using the Mann-Whitney U-test. This test was used because both the raw data and their transformation f a i l e d to s a t i s f y the assumption of variance homogeneity and because the sample sizes are small. Loricas of D. cyli n d r icum were s i g n i f i c a n t l y larger than those of D. divergens by this te s t . T W O - S A M P L E T - T E S T S V A R I A B L E S P E C I E S D . C Y L D . D I V T E S T S T A T I S T I C D F S I G N I F 5 . M E A N 4 0 . 0 8 5 3 8 . 8 4 2 T = 4 . 5 6 0 1 3 5 8 . 0 0 0 0 L O R . L E N V A R 5 . 3 5 0 7 7 . 9 8 0 2 F = 1 . 4 9 1 4 1 8 2 , 1 7 6 . 0 0 3 9 ( T O T A L = 3 6 0 ) N 1 7 7 1 8 3 P R O B M S T M E A N > 2 N D j D A T A ) = 1 . O O O O 8 . M E A N 1 . 6 0 2 3 1 . 5 8 B 2 T = 4 . 6 7 3 7 3 5 8 . 0 0 0 0 L O G . L E N V f l R . 6 3 6 6 8 - 3 . 9 9 4 2 5 - 3 F = 1 . 5 6 1 6 1 8 2 , 1 7 6 . 0 0 1 5 ( T O T A L = 3 6 0 ) N 1 7 7 1 8 3 P R O B ( 1 S T M E A N > 2 N D j D A T A ) = 1 . O O O O 9 M E A N 1 . 6 0 2 3 1 . 5 8 8 2 T = 4 . 6 7 3 7 3 5 8 . 0 0 0 0 S O R T L E N V & R . 6 3 6 6 8 - 3 . 9 9 4 2 5 - 3 F = 1 . 5 6 1 6 1 8 2 , 1 7 6 . 0 0 1 5 ( T O T A L = 3 6 0 ) N 1 7 7 1 8 3 P R O B M S T M E A N > 2 N D j D A T A ) = 1 . O O O O T W O - S A M P L E C O M P A R I S O N T E S T O F 5 . L O R . L E N S I G N I F M A N N - W H I T N E Y U - 1 1 5 5 4 . 0 0 0 0 M E D I A N T E S T . 0 0 0 2 S P E C I E S " N A V G . R A N K M E D I A N = 4 0 . 0 0 0 N ' N > N = D . C Y L 1 7 7 2 0 6 . 7 2 3 6 9 6 8 4 0 D . D I V 1 8 3 1 5 5 . 1 3 7 1 0 6 4 7 3 0 T O T A L 3 G O O U T O F 3 G 0 139 APPENDIX M - ANALYSIS OF LORICA LENGTH ESTIMATES The descriptive s t a t i s t i c s and analysis for i n t e r s p e c i f i c differences, are detailed here for the estimate of l o r i c a length derived from the length of the longest branch (Colony Length) and the number of l o r i c a s in the longest branch. Again, as in the analysis of the l o r i c a lengths measured d i r e c t l y , the l o r i c a length of p. cylindricum i s s i g n i f i c a n t l y greater than that of D. divergens. D E S C R I P T I V E M E A S U R E S < 1 > S P E C I E S : D . C Y L N V A R I A B L E N M I N I M U M M A X I M U M 5 0 . L O R L E N 2 0 5 2 3 3 8 3 3 6 6 . 7 0 0 M E A N S T D D E V 3 3 . 3 5 7 4 . 3 0 7 2 D E S C R I P T I V E M E A S U R E S < 2 > S P E C I E S : D . D I V V A R I A B L E N M I N I M U M M A X I M U M M E A N S T D D E V 5 0 . L O R . L E N 1 2 3 7 1 0 . 8 7 5 6 9 . 6 0 0 3 0 . 5 0 3 4 . 2 6 2 9 T W O - S A M P L E T - T E S T S V A R I A B L E S P E C I E S D . C Y L N D . D I V T E S T S T A T I S T I C D F S I G N I F 5 0 . M E A N 3 3 . 3 5 7 3 0 . 5 0 3 T = 1 8 . 4 7 8 3 2 8 7 . 0 0 0 0 L O R . L E N V A R 1 8 . 5 5 2 1 8 . 1 7 2 F = 1 . 0 2 0 9 2 0 5 1 . 1 2 3 6 . 3 4 4 0 ( T O T A L = 3 2 9 3 ) N 2 0 5 2 1 2 3 7 P R D B M S T M E A N > 2 N D j D A T A ) = 1 . O O O O . 9 5 0 0 C O N F . I N T . O N D I F F ( U N E Q U A L V A R I A N C E S ) ' ( 2 . 5 5 1 9 . 3 . 1 5 5 8 ) 140 APPENDIX N ANALYSIS OF COLONY WIDTH Plots of colony width against colony size (#LPC)r using both the raw data and their log transformation are given here for both species of Dinobryon. The regression analysis of the former and the analysis of covariance on the l a t t e r are also given. The ANCOVA was carried out on log transformed data to minimize the homoscedasticity apparent in the raw data. In the scatter plots, values are plotted with an "*". When values overlap, the number of overlapping values i s plotted unless they exceed 9 , in which case they are designated by an "X". Plots and Regression Analysis of Raw data. S C A T T E R P L O T T O T . W I D 2 5 0 - 0 0 <1> S P E C I E S : D . C Y L N 2 0 5 5 O U T OF 2 0 5 5 1 3 . T O T . W I D V S 8 . L O R I C A * S C A T T E R P L O T T O T W I D 2 5 0 . 0 0 < 1 > S P E C I E S : D . D I V 1 2 3 7 O U T O f 1 2 3 8 1 3 . T O T . W I D V S . 8 . L O R I C A * , , . . . . 2 2 . 2 3 * 3 4 • • • , . 2 . . 2 » 2 * 4 2 « » * 3 * 5 2 3 3 2 ' 4 3 2 * » 2 * 2 2 4 2 6 6 X 3 6 7 4 3 2 2 - * • 4 - 4 X 6 9 7 3 X 2 3 2 4 * * 2 8 4 4 X 3 6 7 2 4 2 3 * • 2 2 7 5 X X 8 X X 2 * 2 4 2 * • 2 * 5 9 X X X X X X X 2 * 2 3 2 • * 3 5 9 X X X X X X 8 6 2 4 * * 2 8 X X X X X X X 5 4 • • 6 X X X X X X 9 5 3 2 2 2 X X X X X X X 3 3 * * • X X X X X X X 7 * • • X X X X X 5 5 " • X X X X 3 3 • • X X X 3 2 X X 3 * 2 3 2 * 3 * • 3 * 2 4 3 3 2 4 2 - 3 4 4 * 4 2 * • 3 2 2 3 2 9 3 8 2 * 2 3 2 2 X 4 2 2 3 5 2 * • 3 * * 9 7 4 2 5 7 2 • 3 4 6 9 2 7 4 6 2 * 2 * 2 8 X X 5 X X 9 9 2 3 * * 5 6 X X X 7 7 9 6 * * * • • 4 X X X X X 9 « 3 * 2 X X X X 8 8 2 6 2 " 6 X X X 4 8 4 3 * X X X X 8 4 2 2 2 X X X 2 2 * • x x x 3 • 7 X 8 * X X 4 L O R I C A * 1 0 0 . 0 0 L O R I C A * 1 0 0 . O O L E A S T S Q U A R E S R E G R E S S I O N S T R A T - S P E C I E S : 0 . C Y L N L E A S T S Q U A R E S R E G R E S S I O N S T R A T " S P E C I E S : D . D I V A N A L Y S I S OF V A R I A N C E OF 1 3 . T O T . W I D N - 2 0 5 5 o u r o r 2 0 5 5 A N A L Y S I S OF V A R I A N C E OF 1 3 . T O T . W I O N -> 1 2 3 7 OUT OF 1 2 3 8 S O U R C E D F S U M S O R S M E A N S O R F - S r A T S I G N I F S O U R C E D F S U M S O R S M E A N S O R F - S T AT S I G N I F R E G R E S S I O N E R R O R T O T A L 1 2 0 5 3 2 0 5 4 . 1 6 1 0 8 . 7 0 6 6 B . 2 3 1 7 5 + 7 • 6 + 7 . 1 6 1 0 8 * 7 3 4 4 . 2 2 4 6 7 9 6 0 . R E G R E S S I O N 1 E R R O R 1 2 3 5 T 0 1 A L 1 2 3 6 . 1 4 5 9 5 * 7 . 6 7 5 2 9 * 6 . 2 1 3 - 1 8 * 7 . 1 4 5 9 5 • ' 5 4 6 7 9 7 2 6 R 9 . 2 0 . M U l . T R = . 8 3 3 7 1 R - S Q R " . 6 9 5 0 7 S E - 1 8 . 5 5 3 M U L I 8 2 6 8 5 R - S Q R ' . 6 8 3 6 8 S E ' ' 2 3 . 3 8 J V A R I A B L E P A R T I A L C O E F F S T D E R R O R 1 - S I A I S 1 G N I F V A R I A B L E P A R T I A L C O E F F S T O E R R O R 1 - S 1 A I S I G N I F C O N S T ANT 8 . L O R I C A * . 8 3 3 7 1 t 9 . 7 2 5 2 . 9 7 4 6 . 7 3 6 6 3 . 4 3 4 8 3 - 1 2 6 7 7 7 6 B . 4 0 8 0 . 0 . C O N S 1 ANT 8 . L O R I O A " 8 2 G 8 5 2 7 . 3 8 6 3 . 0 2 3 5 1 . 0 2 4 1 . 5 8 5 2 ? -2 6 . M 2 1 5 1 6 6 5 0 . 0 . 141 Plots and ANCOVA of Log Transformed Data S C A T T E R P L O T N" L O G . V 12 <1> SPCCIES:0.CYLN 2055 OUT OF 2055 112LOG.V12 VS. 102.LOG.VB 2 5488 + • . . . 2 2' • • ••23«4«« *2 • • '4 «62244 45729 2 2 3*2 462X2XXX95X424 3 * 2 • 2»777XX9X7XXBX742632 2 3005 • • • 45 756XXXXXXXXXXX2X73* • • 3 2 ex XXXXXXXXX7XX97»3 22 2 5 2 4 XX XXXXX8XXX5755*** + • X X X XX XXXX9XXB6 334* 2 a X X X XX XXXX4X7 3*** 2 4 8 X X XB 45X5423* 2 052 3 + 5 X X X B 99 2* 223* * • X X X X X X6 2 -2 * • 2 8 X X 6 X 42 2 •*• a 9 X e 3 5 2 5 4 6 • • X X 6 5 2 • 1 8040 + X X 6 4 • • 1 - W A Y COVARIANCE MODEL ANALYSTS OF VARIANCE OF 112.L0G.V12 N« 3293 OUT OF 3293 L O G .V8 1 . 7 4 0 4 BETWEEN MEANS COVARI A ICS ERROR REGRESSION EQUAL AOJ MEANS ERROR OVERALL REGRESSION EQUAL REGRESSIONS EQUAL AOJ MEANS EQUAL SLOPES ERROR)EACH REGR) TOTAL• DF SUM SORS MEAN SOR F-STAT 3289 3292 4 . 7802 73.399 25.565 76.224 1 .9550 25.565 76.224 1 .9670 1.9550 .120O1 25 553 103.74 73.399 .77704 1.9550 .77704 .12001 .77691 126.59 1 .5447 SIGNIF 0. . OOOO .OOOO . 2 140 S C A T T E R P L O T < t > S P E C I E S : 0 . 0 I V N- 1 2 3 8 O U T OF 1 2 3 8 1 1 2 . L O G . V 1 2 V S . 1 0 2 . L O G . V 8 TABLE OF COEFFICIENTS COVARI A T E S T D E R R O R 2 5038 * 2 . • 102.LOG.ve 43138 44386 .. . >2 • •• 3* -5 24322* • TABLE OF MEANS AND REGRESSIONS • •2442322552*4282* • 2 • 4**4*6557X34*3* 3 * SPECIES D.CYLN 0.DIV 2 2761 + 22* 2*9448779X3X82*4*2* MEAN 2 . 1787 2.lOOO • • 24* 73X59X4XX745332 ADJ MEAN 2 . 1681 2 1 176 • 3 347 XXXB 6344* *2* • ( STD ERROR) .19476 -2 .25118 -2 • • • 4 259 XXXX7X595622* * INTERCEPT 1 . 7289 1 .6784 3 6 7 X69 X6X4253542 N 2055 1238 3 8 X X79 6773-32 * * 2 04B5 • 3 6 X X X xs 576 2322* ! CONSTANT 1 . 7340 1 .6723 9 X X 8 X42 3 2 •• * * ! 102.LOG.V8 . 42647 .43757 a x X X X4* • • a 1 SE OF REGR .87945 -1 .88469 - 1 + 5 8 X B 2-2 2 R-SQR . 7 1565 .77566 3 9 4 4 4 2* SIGNIF o. 0. T - S T A T S I G N I F 97.190 O. 1 8208 + LOG.VB 1 .9590 142 APPENDIX 0 - ANALYSIS OF COLONY LENGTH Plots of colony length against colony size (#LPC), using both the raw data and their log transformation are given here for both species of Dinobryon. The regression analysis of the former arid the analysis of covariance on the l a t t e r are also given. The ANCOVA was ca r r i e d out on log transformed data to minimize the homoscedasticity apparent in the raw data. In the scatter plots, values are plotted with an "*". When values overlap, the number of overlapping values is plotted unless they exceed 9, in which case they are designated by an "X". Plots and Regression Analysis of Raw Data. S C A T T E R P L O T T O T . L E N 36O.0O < 1 > S P E C J E S : D . D I V 1 2 3 8 OUT OF 1 2 3 8 1 2 . T O T . L E N V S . 8 . L O R I C A * S C A T T E R P L O T T O T . L E N 360.OO <1> S P E C I E S : O . C r L N 2 0 5 5 OUT OF 2 0 5 5 1 2 . T O T . L E N V S . B . L O P l C A * 2 * 2 " * 2 * • • • * 4 * 3 * * • 2 2 2 * " * * • • " 2 3 2 4 5 3 2 3 7 3 2 * 2 2 2 * 2 2 * ' • 2 2 * 2 3 5 4 5 3 2 2 2 * 2 • * • 5 5 8 9 5 5 8 * 5 4 3 * * * 2 * 2 • 7 8 8 X 8 X X X X 6 5 4 2 * * " * • 3 4 3 8 8 6 3 6 7 2 * 4 * * * • 3 9 X X X 9 6 6 3 3 * * * • • 5 4 X X 9 7 X 6 3 4 " • * 3 X X X X X 3 8 5 4 2 . 3 X X X X 5 3 5 * • • X X X 8 8 4 2 3 x x x 5 * * 4 X X X 3 2 X X X 4 X X 7 X 4 * * 2 3 2 2 2 2 ' • 4 * 3 * 2 3 * 3 2 4 2 * 3 * * * 2 3 2 4 5 5 2 5 3 2 * 2 2 * * 2 3 * 7 3 4 6 3 * 5 2 * * " 2 3 4 6 B 5 7 3 8 7 6 8 3 2 * * 2 3 " * * ' 5 X X X X X 7 9 2 S 6 3 2 2 * • 3 6 7 X X X X X X 9 5 4 * 3 3 3 * • • • 2 X 9 X X X X 5 X 7 3 6 2 2 3 3 2 " 3 K X X X X X X X X X 5 2 3 ' 2 * • 5 X X X X X X X 6 4 6 2 * * * X X X X X X X 9 5 3 2 2 * 5 v XX X X X G 4 * • • • 6 X X X X X X * * • • X X X X X 8 5 3 X X X B 4 * 2 * X X X 8 ' 3 * X X X X * x x e * L O R I C A * 100.OO L O R I C A * 10O.OO L E A S T S Q U A R E S R E G R E S S I O N S T P A T - S P E C I E S : D . D T V L E A S T S Q U A R E 5 R E G R E S S I O N 5 T R A T ' S P E C I E S . 0 C Y L N A N A L Y S I S OF V A R I A N C E OF 1 2 . T O T . L E N N - 12 3 8 OUT OF 1 2 3 8 A N A L Y S I S O F V A R I A N C E OF 1 2 . T O T L E N ' 2 0 5 5 OUT OF 2 0 5 5 S D U P C E DF S U M 5 0 R S M E A N S Q P r - ST AT S I G N I F S O U R C E D F S U M S Q R S M E A N S O R F - ST AT S I G N I F R E G R E S S I O N 1 . 2 0 4 0 7 • 7 . 2 0 4 0 7 '7 18*55. 2 0 . R E G R E S S I O N . 1 . 3 3 3 2 4 * 7 . 3 3 3 2 4 «1 1 2 7 6 " . 6 0 . t e n o n 1 2 3 6 . 1 3 5 2 3 * 7 1 0 9 4 . 1 E R R O R 2 0 5 3 . 2 4 7 0 2 • 7 1 2 0 3 . 2 T O T A L 1 2 3 7 . 3 3 9 3 0 * 7 T O T M 2 0 5 4 . 5 8 0 2 6 * 7 M U L T P * 7 7 5 5 3 R - S Q R * . 6 0 1 4 5 S E - 3 3 . 0 7 7 M U L T P= . 7 5 7 8 3 R - S Q R -' . 5 7 4 3 0 S E • • 3 4 . 6 8 7 V A R I A B L E P A R T I A L C O E F F S T D E R R O R T - S T AT S I G N I F VA01 a p t F P A R T I A L C O E F F S T O E R R O R T - ST AT S I G N I F C O N S T ANT 8 9 . 2 6 0 1 4 4 8 5 6 1 f-24 0 . C O N S I ANT 1 0 O 6 1 1 3 7 7 2 7 3 050 0 . 8 . L O P ! r . A * . 7 7 5 5 3 3 . 57?1 . 8 2 7 l O - 1 •13 18 8 0 . S . L O P t r A * 7 5 7 8 3 4 . 2 7 8 5 . 8 1 2 9 7 -1 I 5 2 K27 0 . 143 Plots and ANCOVA of Log Transformed Data, S C A T T E R P L O I L 0 G 1 3 2 . 3 3 1 6 < 1 > S P E C 1 E S : D . C V L N 2 0 5 5 OUT OF 2 0 5 5 4 3 . L 0 G 1 3 V S . 1 . 7 7 4 8 + 1 . 4 9 6 4 + • . • • • 4 • 2 * • • » 2 2 " 2 * 2 3 * * • - * 7 * 3 5 2 " 2 * * * * • 2 2 * 2 5 2 6 4 * 7 7 2 5 2 2 2 3 2 4 9 X X X X 8 X 7 5 5 * 2 2 7 2 4 3 X 4 5 X 6 9 2 3 2 3 2 3 " 3 7 9 7 X 9 X 9 X X X 2 3 7 4 2 * 4 6 3 8 2 9 X X X 7 X 9 3 * * * • 2 4 5 6 7 6 4 X X 6 X 3 B 5 3 5 " 4 5 X X X X X X X X X B 8 S 2 * X 6 X X X X X X X 3 6 2 3 2 2 XX X X X X 8 X X M 4 2 X X X 7 X 9 3 7 5 3 2 2 * X 6 8 6 4 8 9 9 5 2 * X X 8 6 X 9 4 5 3 * * • 9 9 2 3 4 4 • X 5 5 3 * * 2 3 6 X • * 2 • 3 3 2 * • • 2 1 - W A V C O V A R I A N C E M O D E L A N A L Y S I S OF V A R I A N C E OF 4 3 . L 0 G 1 3 N - 3 2 9 2 OUT O F 3 2 9 3 L O G . V 8 1 . 7 4 0 4 S C A T T E R P L O t . L O G 1 3 2 3 7 6 2 <1> S P E C I E S : D . D I V 1 2 3 7 OUT OF 1 2 3 8 4 3 . L 0 G 1 3 V S . 1 0 2 . L O G . V 8 2 • * • • • 4 * 2 2 * * 2 3 5 * 2 6 2 4 3 2 2 2 * 2 2 3 4 3 3 6 2 * * * 2 * 2 2 * S * 4 * 6 2 2 2 * 2 * 2 * 2 6 2 3 5 8 7 4 9 6 X 4 3 * 4 * 2 2 * 4 3 2 7 3 B 5 2 6 7 2 2 * * 3 2 6 6 X 8 2 B 7 X X 9 2 6 * * * • 3 5 7 9 X 5 4 6 3 6 6 3 * 6 2 7 6 7 9 6 5 6 4 4 3 • • • 3 5 X 9 X 9 4 8 7 4 » 3 * * 8 X 5 X 2 X 2 - 5 5 2 X 7 2 8 * 8 2 2 2 * * X 5 8 8 3 3 2 2 2 2 8 5 3 * 4 4 7 2 2 S O U R C E O F S U M S Q R S M E A N S O R F - S T AT S I G N I F B E T W E E N M E A N S 1 . 2 5 I S O C O V A R I A T E S 1 3 0 2 3 B 2 0 3 3 8 1 1 0 4 7 . 0 . E R R O R 3 2 8 9 6 0 . 2 5 6 . 1 B 3 3 0 - 1 R E G R E S S I O N 1 1 9 9 . 3 8 E Q U A L A D J M E A N S 1 3 . 2 4 3 3 3 . 3 4 3 3 1 7 7 . 0 3 . O O O O E R R O R 3 2 B 9 6 0 2 5 6 . 1 8 3 3 0 - 1 O V E R A L L R E G R E S S I O N 1 1 9 9 3 8 E O U A L R E G R E S S I O N S 2 3 . 2 8 0 1 1 . 6 4 0 1 8 9 . 5 4 8 O O O O E Q U A L A D J M E A N S t 3 . 2 4 3 3 E O U A L S L O P E S 1 . 3 6 8 1 2 - 1 3 6 8 1 2 - 1 2 . 0 1 0 0 . 1 5 6 4 E R R O R ) E A C H R E G R ) 3 2 8 8 6 0 3 1 9 . 1 B 3 1 5 - 1 T O T A L 3 2 9 < 2 6 2 . 8 8 O f C O E F F I C I E N T S C O V A R 1 AT E C O E F F S T D E R R O R T - S T A T S I G N I F L O G . V B 7 1 6 S 4 . 6 8 1 7 5 - 2 1 0 5 . 1 0 0 . T A B L E DF M E A N S A N D R E G R E S S I O N S S P E C I E S M E A N A D J M E A N ( S T O E R R O R ) I N T E R C E P T hi C O N S T A N T . 1 0 2 . L O G . V B S € OF R E G R R - S O R S I G N I F D . C Y L N 1 . 7 1 8 1 1 . 7 0 0 4 . 2 9 9 0 5 - 2 . 9 7 0 9 4 2 0 5 5 . 9 7 9 9 2 . 7 0 7 9 3 . 1 2 9 7 9 . 7 6 1 0 0 0 D I V 1 . 7 3 6 1 1 . 7 6 5 5 . 3 8 5 8 5 I . 0 3 6 0 1 2 3 7 t . 0 2 5 4 . 7 2 7 3 8 . 1 4 4 0 7 . 7 8 2 6 3 0 . 1 . 5 6 7 2 L O G . V B 1 . 9 5 9 0 PAGE 144 OMITTED 145 D . d i v e r g e n s C o l o n y S i z e D A T E D E P T H # L P C S . E . N C O M B I N E D # L P C S . E . N J A N 6 1 0 . 0 . 0 2 - - - 0 . 0 . 0 3 0 . 0 . 0 J A N 1 3 1 0 . 0 . 0 2 0 . 0 . 0 0 . 0 . 0 3 0 . 0 . 0 J A N 2 0 1 0 . 0 . 0 2 0 . 0 . 0 0 . 0 . 0 3 0 . 0 . 0 J A N 2 8 1 0 . 0 . 0 2 o . 0 . 0 0 . 0 . 0 3 0 . 0 . 0 F E B 3 1 0 . 0 . 0 2 4 0 . 0 0 6 . 2 4 5 3 2 9 . 8 0 7 . 2 6 2 5 3 1 4 . 5 0 4 . 5 0 0 2 F E B 1 0 1 1 9 . 0 0 0 . 0 0 0 1 2 0 . 0 . 0 1 9 . 0 0 0 . 1 3 0 . 0 . 0 F E B 1 7 1 0 . 0 . 0 2 0 . 0 . 0 0 . 0 . 0 3 0 > ' 0 . 0 F E B 2 4 1 3 0 . 0 0 O . O O O 1 2 0 . 0 . 0 3 0 . 0 0 0 . 1 3 0 . 0 . 0 M A R 3 1 2 1 . 4 3 4 . 0 5 2 7 2 3 6 . O O 1 2 . 0 0 0 2 2 3 . 1 8 3 . 5 8 0 1 7 3 2 1 . 5 0 6 . 1 7 6 8 M A R 1 0 1 - - -2 - - - - - -3 - - -M A R 1 7 1 2 9 . 2 6 2 . 4 1 1 6 2 2 2 1 . 5 3 2 . 0 9 4 6 2 2 1 . 8 1 1 . 2 2 3 1 8 4 3 1 4 . 4 0 1 . 1 9 6 6 0 M A R 2 4 1 1 6 . 7 3 1 . 5 9 2 6 2 2 1 9 . 9 8 1 . 3 7 3 6 2 1 6 . 8 4 . 9 0 3 1 5 5 3 1 0 . 7 7 1 . 0 2 7 3 1 M A R 3 1 1 1 7 . 2 6 1 . 4 0 8 6 2 2 1 3 . 4 5 1 . 1 1 0 6 2 1 5 . 0 5 . 7 2 1 1 8 6 3 1 4 . 4 5 1 . 1 8 0 6 2 A P R 7 1 1 7 . 0 3 1 . 3 3 4 6 2 2 1 3 . 0 5 1 . 0 8 3 6 2 1 3 . 3 6 . 6 8 8 1 8 6 3 1 0 . 0 0 . 9 7 0 6 2 A P R 1 4 1 1 0 . 4 7 1 . 0 5 0 6 2 2 9 . 4 5 . 8 2 6 6 2 9 . 5 3 . 5 0 7 1 8 6 3 8 . 6 8 . 7 2 4 6 2 A P R 2 1 1 8 . 2 4 . 7 1 2 6 2 2 7 . 3 9 . 5 9 2 6 2 7 . 2 6 . 3 7 5 1 8 6 3 6 . 1 5 . 6 2 2 6 2 A P R 2 8 1 6 . 9 7 . 7 8 8 3 3 2 7 . 6 9 . 9 5 7 4 5 6 . 6 5 . 4 4 3 1 3 1 3 5 . 5 7 . 5 2 6 5 3 1 46 APPENDIX Q - COLONY SIZE DIFFERENCES BETWEEN DEPTHS Univariate oneway ANOVAS testing for differences between the mean colony size of each species at 1, 2 & 3M are detailed in this appendix. The data were log transformed to meet the assumption of variance equality. U N I V A R I A T E 1 - W A Y A N O V A < 1 > D E P T H : O N E * S P E C I E S : D . C Y L N < 2 > D E P T H : T W O * S P E C I E S : D . C Y L N < 3 > D E P T H : T H R E E * S P E C I E S : D . C Y L N A N A L Y S I S O F V A R I A N C E O F 1 0 2 . L O G . V 8 N = 2 0 5 5 O U T O F 2 0 5 5 S O U R C E D F S U M O F S O R S M E A N S O R F - S T A T I S T I C S I G N I F 2 1 . 5 2 5 . 0 0 0 0 B E T W E E N W I T H I N T O T A L 2 4 . 5 1 5 2 2 . 2 5 7 6 2 0 5 2 2 1 5 . 2 1 . 1 0 4 8 8 2 0 5 4 2 1 9 . 7 3 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 1 4 3 3 E T A - S Q R = . 0 2 0 5 ( V A R C O M P = . 3 1 5 1 0 - 2 % V A R A M O N G = 2 . 9 2 ) E Q U A L I T Y O F V A R I A N C E S : D F = 2 , . 9 3 5 7 1 + 7 F = 2 . 1 1 0 5 . 1 2 1 2 S T R A T A N M E A N V A R I A N C E S T D D E V < 1 > 6 9 9 1 . 0 9 5 2 . 9 8 0 4 1 - 1 . 3 1 3 1 2 < 2 > 7 3 8 1 . 0 4 6 9 . 1 0 3 1 0 . 3 2 1 1 0 < 3 > 6 1 8 . 9 7 8 1 6 . 1 1 4 7 4 . 3 3 8 7 3 G R A N D 2 0 5 5 1 . 0 4 2 7 . 1 0 6 9 8 . 3 2 7 0 7 U N I V A R I A T E 1 - W A Y A N O V A < 1 > D E P T H : O N E * S P E C I E S : D . D I V < 2 > D E P T H : T W O » S P E C I E S : D . D I V < 3 > D E P T H : T H R E E * S P E C I E S : D . D I V A N A L Y S I S O F V A R I A N C E O F 1 0 2 . L O G . V 8 N = 1 2 3 8 O U T O F 1 2 3 8 S O U R C E D F S U M O F S Q R S M E A N S Q R F - S T A T I S T I C S I G N I F 2 6 . 4 2 9 . O O O O B E T W E E N W I T H I N T O T A L 2 7 . 1 6 9 9 3 . 5 8 4 9 1 2 3 5 1 6 7 . 5 2 . 1 3 5 6 5 1 2 3 7 1 7 4 . 6 9 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 2 0 2 6 E T A - S Q R = . 0 4 1 0 ( V A R C O M P = . 8 3 6 0 2 - 2 % V A R A M O N G = 5 . 8 1 ) E Q U A L I T Y O F V A R I A N C E S : D F = 2 , . 3 4 2 8 7 + 7 F = . 5 7 3 9 4 . 5 6 3 3 S T R A T A N M E A N V A R I A N C E S T D D E V < 1 > 4 1 4 1 . 0 5 4 8 . 1 4 2 1 6 . 3 7 7 0 3 < 2 > 4 2 2 1 . 0 O 1 7 . 1 2 8 1 2 . 3 5 7 9 4 < 3 > 4 0 2 . 8 7 2 2 9 . 1 3 6 8 4 . 3 6 9 9 2 G R A N D 1 2 3 8 . 9 7 7 4 2 . 1 4 1 2 2 . 3 7 5 8 0 147 APPENDIX R - OTHER COLONY VARIABLES This appendix contains the d e t a i l s of colony morphometric measurements for both Dinobryon species from Station I samples, a l l depths combined. D. cyl Indrlcura DATE * # * COLONY COLONY LPC EMPTY STATO BRANCH LENGTH WIDTH JAN 6 9 9 2.2 0.0 4.3 152.3 50.8 MEAN 1 . 12 0.53 0. 0.23 8. 15 5.49 SE 26 26 26 26 26 26 N JAN 13 6 8 1 .2 0.0 3.6 139.7 43 8 MEAN 1.81 0.39 0. 0.37 13.38 8 .04 SE 10 10 10 10 10 10 N JAN 20 9.4 1.5 0.0 4.3 149.0 50.9 MEAN 1 .27 0.32 0. 0.32 12.99 6 . 16 SE 27 27 27 27 27 27 N JAN 27 11.9 2.0 0.0 4 . 7 160.2 49.4 MEAN 0 68 0. 17 0. 0.42 5.26 2.54 SE 120 120 120 120 120 120 N FEB 3 13.2 1 . 7 0.0 5.0 170.8 54.5 MEAN 0.50 0. 15 0. 0.40 3.49 1 .85 SE 155 155 155 155 155 155 N FEB 10 13.4 0.5 0.04 5. 1 174.0 54 .6 MEAN 0.38 0.06 0.03 0.07 2.76 1 .49 SE 186 186 186 186 186 186 N FEB 17 14 . 1 0.5 0.04 4.9 167 .4 56 . 5 MEAN 0.81 0. 11 0.04 0. 13 5.03 2.84 SE 106 106 106 106 106 106 N FEB 24 13 . 1 0.9 0.0 4.8 168.8 56.4 MEAN 0.84 0. 12 0. 0. 14 5. 17 2.70 SE 87 87 87 87 87 87 N MAR 3 14 . 2 0.9 0.0O5 5. 1 170. 2 56.6 MEAN 0. 48 0.9 0.005 0.09 3.11 1 .74 SE 186 186 186 186 186 186 N MAR 10 - - - - - - MEAN - - - - - SE - - - - - N MAR 17 6.2 3.2 0.0 3.4 110.6 31 .4 MEAN 0.40 0.21 0. 0. 11 3.36 1 .80 SE 156 156 156 156 156 156 N MAR 24 21.8 2 . 1 0.02 6. 1 198.0 87 .7 MEAN 0.99 0.21 0.01 0. 13 4.51 2.93 SE 124 124 124 124 124 124 N MAR 31 24.7 1 .7 0.01 6.3 199 7 95.2 MEAN 0.84 0. 1 0.007 0. 10 3.2 2.34 SE 185 185 185 185 185 185 N APR 7 18 8 2.7 0.07 5.7 185. 1 83.5 MEAN 0. 78 0.2 0.02 O. 12 3.86 2.98 SE 1B3 183 183 183 183 183 N APR 14 15.2 4.9 o.oi 4.9 150.6 72.4 MEAN 0.66 0.23 0.00 0. 10 3.25 2.98 SE 185 185 185 185 185 185 N APR 21 9.2 5.2 0.0 3.4 125.6 51.6 MEAN 0.40 0.40 0. 0 0 9 3 01 1 .95 SE 186 186 186 186 1B6 186 N APR 28 7.0 4 . 1 0. 3.4 114.4 44 . 9 MEAN 0.39 0.26 0. 0.30 3.27 SE 133 133 133 133 133 133 N 1 48 D . d i v e r g e n s D A T E # It * / L C O L O N Y C O L O N Y L P C E M P T Y S T A T O B R A N C H L E N G T H W I D T H J A N 6 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 M E A N 0 . 0 . 0 . 0 . 0 . 0 . S E 0 0 0 0 0 0 N J A N 1 3 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 M E A N 0 . 0 . 0 . O . 0 . 0 . S E 0 0 0 0 0 0 N J A N 2 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 M E A N 0 . 0 . 0 . 0 . 0 . 0 . S E 0 0 0 0 0 0 N J A N 2 7 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 M E A N 0 . 0 . 0 . 0 . 0 . 0 . S E 0 0 0 0 0 0 N F E B 3 2 9 . 8 0 . 2 0 . 0 6 . 2 1 8 9 . 6 0 1 2 0 . 1 M E A N 7 . 2 6 0 . 0 9 0 . 0 . 5 1 2 3 . 5 8 2 0 . 5 9 S E 5 5 5 5 5 5 N F E B 1 0 1 9 . 0 3 . 0 0 . 0 5 . 0 1 7 1 . 1 5 8 . 0 M E A N 0 . 0 . 0 . 0 . 0 . 0 . S E 1 1 1 1 1 1 N F E B 1 7 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 M E A N 0 . 0 . 0 . 0 . 0 . 0 . S E 0 0 0 0 0 0 N F E B 2 4 3 0 . 0 2 . 0 0 . 0 6 . 0 1 8 8 . 5 - M E A N 0 . 0 . 0 . 0 . 0 . - S E 1 1 1 1 1 - N M A R 3 2 3 . 2 1 . 5 o.o 6 . 1 1 8 4 . 2 1 0 3 . 9 M E A N 3 . 5 8 0 . 7 7 0 . 0 . 3 9 1 1 . 6 4 1 1 . 3 5 S E 1 7 1 7 1 7 1 7 1 7 1 7 N M A R 1 0 - - - - - - M E A N - - - - - - S E - - - - - - N M A R 1 7 2 1 . 8 3 . 2 0 . 0 0 5 5 . 7 1 6 8 . 9 8 8 . 0 M E A N 1 . 2 2 O . 2 1 0 . 0 0 5 0 . 1 4 4 . 3 3 3 . 6 2 S E 1 8 4 1 8 4 1 8 4 1 8 4 1 8 4 1 8 4 N M A R 2 4 1 6 . 8 2 . 3 0 . 5 6 5 . 3 1 5 4 . 9 8 2 . 0 M E A N 0 . 9 0 0 . 1 9 0 . 0 9 0 . 1 4 3 . 8 8 3 . 4 2 S E 1 5 5 1 5 5 1 5 5 1 5 4 1 5 5 1 5 5 N M A R 3 1 1 5 . 1 2 . 4 0 . 6 8 5 . 1 1 4 7 . 9 7 1 . 4 M E A N 0 . 7 2 O . 1 7 0 . 0 9 0 . 1 2 3 . 4 2 2 . 8 1 S E 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 N A P R 7 1 3 . 4 3 . 1 0 . 5 1 4 . 8 1 4 2 . 0 6 7 . 3 M E A N 0 . 6 9 0 . 2 0 . 0 8 0 . 1 2 3 . 6 4 2 . 7 1 S E 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 N A P R 1 4 9 . 5 3 . 7 0 . 0 3 4 . 2 1 2 2 . 6 5 7 . 0 M E A N 0 . 5 1 0 . 1 8 0 . 0 1 0 . 1 0 3 . 0 2 2 . 7 2 S E 1 8 5 1 8 5 1 8 5 1 8 5 1 8 5 1 8 5 N A P R 2 1 7 . 3 2 . 6 0 . 0 1 6 3 . 4 1 0 4 . 4 5 0 . 2 M E A N 0 . 3 8 0 . 1 6 0 . 0 0 9 0 . 1 1 3 . 0 9 3 . 6 8 S E 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 1 8 6 N A P R 2 8 6 . 5 3 . 2 0 . 3 . 3 1 0 5 . 1 5 0 . 3 M E A N 0 . 4 4 0 . 2 0 0 . 0 . 1 1 3 . 1 0 2 . 9 1 S E 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 1 3 1 N 1 49 APPENDIX S - ZOOPLANKTON ABUNDANCES Detailed on the following pages are the temporal changes in individual zooplankton species, at each depth and for a l l three depths combined for both stations. A S P L A N C H N A P R I O D O N T A 9 5 % C . I . L O W E R U P P E R T O T A L D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . E . J A N 3 1 1 1 . 3 . 0 8 . 7 . 6 6 6 6 2 1 . 6 . 1 9 . 0 . 7 2 0 0 1 2 1 . 3 . 0 8 . 7 . 6 6 6 6 3 . 1 1 . 0 2 2 1 . 8 . 1 9 . 4 . 7 6 9 7 4 . 2 1 . 1 9 1 3 • . 4 0 . 0 7 . 2 . 3 8 4 9 2 . 9 0 . 0 8 . 0 . 5 4 4 3 J A N 1 3 1 1 5 . 3 1 . 7 1 4 . 7 1 . 3 3 3 2 2 5 . 1 1 . 6 1 4 . 4 1 . 3 0 5 1 1 2 1 . 8 . 1 9 . 4 . 7 6 9 7 7 . 3 1 . 5 6 2 1 . 6 . 1 9 . 0 . 7 2 0 0 7 . 3 1 . 7 0 1 3 . 2 0 . 0 6 . 8 . 2 7 2 1 2 . 7 0 . 0 7 . 6 . 8 1 6 3 J A N 2 0 1 1 3 . 8 . 9 1 2 . 4 1 . 1 2 2 0 2 4 . 3 1 . 1 1 3 . 2 1 . 1 9 2 4 1 2 1 . 6 . 1 9 . 0 . 7 2 0 0 5 . 6 1 . 3 6 2 1 . 6 . 1 9 . 0 . 7 2 0 0 6 . 3 1 . 4 5 1 3 . 2 O . O 6 . 8 . 2 7 2 1 2 . 4 . 0 . 0 7 . 2 . 3 8 4 9 J A N 2 7 1 1 2 3 . 3 1 4 . 1 3 7 . 9 2 . 7 8 8 5 2 1 6 . 0 8 . 7 2 8 . 8 2 . 3 0 9 1 1 2 5 . 3 1 . 7 1 4 . 7 1 . 3 3 3 2 2 9 . 5 3 . 1 4 2 1 1 . 8 5 . 7 2 3 . 4 1 . 9 8 1 1 3 0 . 0 3 . 1 6 1 3 . 9 0 . 0 8 . 0 . 5 4 4 3 2 2 . 2 . 3 1 0 . 1 . 8 6 0 6 F E B 3 1 1 4 0 . 4 2 7 . 8 5 8 . . 4 3 . 6 7 1 3 2 3 3 . 1 2 1 . 8 4 9 . 7 3 . 3 2 1 8 1 2 1 8 . 5 1 5 . 6 2 1 . 9 3 . 0 4 0 3 5 8 . 9 4 . 7 7 2 1 5 . 0 1 2 . 4 1 8 . . 1 2 . 7 4 1 3 5 2 . 6 4 . 5 6 1 3 - - -2 4 . 5 3 . 1 6 . 3 1 . 4 9 2 6 F E B 1 0 1 1 5 4 . 9 4 9 . 8 6 0 6 5 . 2 4 0 7 2 3 6 . 7 3 2 . 6 4 1 . . 4 4 . 2 8 4 2 1 2 4 1 . 0 3 6 . 6 4 5 . 9 4 . 5 2 5 7 1 1 3 . 0 7 . . 5 2 2 2 0 . 8 1 7 . 7 2 4 . 4 3 . 2 2 6 0 6 3 . 4 5 . . 6 3 1 3 1 7 . 2 1 4 . 4 2 0 . . 5 2 . 9 2 8 9 2 5 . 9 4 . 4 8 . 0 1 . 7 2 0 2 F E B 1 7 1 1 1 6 . 0 1 3 . 3 1 9 . . 2 2 . 8 3 0 8 2 1 6 . 0 1 3 . 3 1 9 . 2 2 . 8 2 4 9 1 2 1 6 . 0 1 3 . 3 1 9 . 2 2 . 8 2 4 9 3 4 . 5 4 . 1 5 2 1 . 6 . 9 2 . 9 1 . 2 6 3 3 1 8 . 6 3 . 1 4 1 3 2 . 5 1 . 6 4 . 0 1 . 1 2 4 1 2 1 . 1 . 5 2 . 2 . 7 2 9 4 F E B 2 4 1 1 1 . 2 . 6 2 . 4 . 7 7 3 6 2 . 2 . 0 1 . 0 . 3 1 5 8 1 • 2 . 2 . 0 1 . . 0 . 3 1 5 8 1 . 7 9 1 2 . 1 . 0 9 . 2 5 7 9 . 5 5 2 1 3 . 3 . 0 1 . 1 . 3 6 4 7 2 . 2 . 0 1 . 0 . 3 1 5 8 150 4 A R 3 1 1 2 . 1 1 . 3 3 . 5 1 . 0 3 1 5 2 5 . 0 3 . 6 6 . 9 1 . 5 7 9 2 1 2 2 . 0 1 . 2 3 . 4 . 9 9 8 7 4 . 7 1 . 5 4 2 1 . 9 1 . 1 3 . 3 . 9 8 2 0 7 . 6 1 . 9 5 1 3 . 6 . 2 1 . 6 . 5 4 7 0 2 . 7 . 2 1 . 7 . 5 7 6 6 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 1 8 . 5 1 5 . 6 2 1 . 9 3 . 0 4 0 3 2 8 . 8 6 . 9 1 1 . 3 2 . 1 0 2 9 1 2 8 . 0 5 . 5 1 1 . 6 2 . 0 0 1 2 2 8 . 9 3 . 8 0 2 7 . 9 5 . 4 1 1 . 4 1 . 9 8 4 5 1 8 . 1 3 . 0 0 1 3 2 . 4 1 . 2 4 . 7 1 . 0 9 6 1 2 1 . 3 . 5 3 . . 3 . 8 1 7 0 1 1 9 2 . 2 8 2 . 9 1 0 2 . 6 6 . 7 9 1 5 2 5 3 . 0 4 6 . 0 6 1 . . 0 5 . 1 4 7 8 1 2 2 5 . 0 2 0 . 3 3 0 . 7 3 . 5 3 3 0 1 1 9 . 9 7 . 7 4 2 1 7 . 8 1 3 . 9 2 2 . 7 2 . 9 7 9 6 7 5 . 2 6 . 1 3 1 3 2 . 7 1 . 4 5 . 1 1 . 1 5 5 4 2 4 . 4 2 . 6 7 . 3 1 . 4 8 4 2 1 1 2 6 . 4 1 9 . 8 3 5 . 1 3 . 6 3 2 0 2 1 1 . . 7 7 , . 5 1 8 . . 1 2 . 4 2 1 4 1 2 7 . . 2 4 . . 0 1 2 . . 5 1 . 8 9 6 8 3 4 . 9 4 . 1 8 2 3 . 2 1 . . 3 7 . . 3 1 . 7 8 8 3 1 5 . 5 3 . 1 2 1 3 1 . . 3 3 4 . . 7 . 8 1 6 2 2 . 5 . 0 3 . . 5 . 7 3 0 0 1 1 4 5 . 3 3 6 . 4 5 6 . . 3 4 . 7 5 9 5 2 2 2 . 9 1 6 . . 8 3 1 . . 2 3 . 3 8 5 2 1 2 1 0 6 . 1 9 2 . . 1 1 2 2 . . 1 7 . 2 8 2 4 1 5 8 . 6 8 . 9 0 2 1 2 8 . 5 1 1 3 . . 0 1 4 6 . 0 . 8 . . 0 1 4 1 1 5 6 . 2 8 . 8 4 1 3 7 . . 2 4 . 0 1 2 . 5 1 . . 8 9 6 8 2 4 . 8 2 . 3 9 . 5 1 . 5 4 8 7 1 1 3 0 . 6 2 3 . 4 4 0 . 0 3 . 9 1 4 6 2 4 5 . 0 3 6 . 2 5 6 . 0 4 . . 7 4 5 4 1 2 3 4 . 9 2 7 . 2 4 4 . 8 4 . . 1 7 8 0 7 2 . 0 6 , . 0 0 2 3 8 . . 6 3 0 . 5 4 8 . 9 4 . 3 9 5 6 9 9 . 1 7 . . 5 7 1 3 6 . 4 3 . 5 1 1 . 5 1 7 8 8 3 2 1 5 . 5 1 0 . 5 2 2 . 5 3 . 9 3 1 4 1 1 5 2 . 8 4 3 . 1 6 4 . 5 5 . 1 3 6 5 2 5 6 . 2 4 6 . 2 6 8 . . 3 5 . 3 0 2 4 1 2 5 2 . 5 4 2 . 9 6 4 . . 2 5 . 1 2 3 5 1 1 1 . 4 7 . 4 6 2 5 4 . 6 4 4 8 6 6 . 6 5 . 2 2 6 5 1 2 3 . 1 7 . 8 5 1 3 6 . 1 3 . 3 1 1 2 1 . 7 5 0 6 2 1 2 . 3 6 . 5 2 2 . 4 2 . 4 7 6 9 1 1 1 4 . 1 9 . 5 2 0 . 9 2 . 6 5 7 5 2 2 2 . 7 1 6 . 6 3 0 . . 9 3 . 3 6 5 4 1 2 6 . 9 3 8 1 2 . . 2 1 . 8 6 1 3 2 4 . 3 3 . 7 1 2 6 . 9 3 . . 8 1 2 . . 2 1 . 8 6 1 3 3 7 . 1 4 . 3 0 1 3 3 . 2 8 1 0 . 2 1 . 7 8 9 1 2 7 . . 5 3 . 3 1 6 . 1 1 . 9 3 2 5 151 B O S M I N A C O R E G O N E 9 5 % C . I . L O W E R U P P E R D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . J A N 6 1 1 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 2 . 7 . 0 7 . . 6 . 4 7 1 3 1 2 3 . 8 . 9 1 2 . 4 1 . 1 2 2 0 1 2 . 0 2 . . 0 0 2 5 . 1 1 . 6 1 4 . 4 1 . 3 0 5 1 1 6 . 2 2 . 3 3 1 3 5 . 1 1 . 6 1 4 . 4 1 . 3 0 5 1 2 1 0 . 4 4 . 8 2 1 . 6 1 . 8 6 5 6 J A N 1 3 1 1 8 . 0 3 . 2 1 8 . 4 1 . 6 3 2 8 2 5 . 3 1 . 7 1 4 . 7 1 . 3 3 3 2 1 2 6 . 7 2 . 4 1 6 . 6 1 . 4 9 0 5 2 8 . 7 3 . 0 9 2 9 . 3 4 . 1 2 0 . 2 1 . 7 6 3 6 2 0 . 3 3 . 2 5 1 3 1 4 . 0 7 . 2 2 6 . 3 2 . 1 6 0 0 2 5 . 7 1 . 9 1 5 . 2 2 . 3 8 0 2 J A N 2 0 1 1 8 . 2 3 . 4 1 8 . 7 1 . 6 5 5 3 2 4 . 8 1 . 4 1 3 . 9 1 . 2 6 4 8 1 2 8 . 4 3 . 5 1 9 . 0 1 . 6 7 7 5 3 0 . 2 3 . 1 7 2 1 0 . 4 4 . 8 2 1 . 6 1 . 8 6 5 6 2 0 . 8 2 . 6 3 1 3 1 3 . 6 6 . 9 2 5 . 7 2 . 1 2 5 4 2 5 . 6 1 . 8 1 5 . O 1 . 3 6 0 7 J A N 2 4 1 1 1 1 . 1 5 . 2 2 2 . 5 1 . 9 2 4 3 2 5 . 6 1 . 8 1 5 . 0 1 . 3 6 0 7 1 2 4 . 4 1 . 2 1 3 . 4 1 . 2 1 7 0 1 8 . 9 2 . 5 1 2 2 . 9 . 5 1 1 . 1 . 9 8 1 2 9 . 3 1 . . 7 6 1 3 3 . 3 . 7 1 1 . 8 1 . 0 5 4 0 2 . 9 . 0 8 . 0 . 5 4 4 3 F E B 3 1 1 8 . 4 3 . 5 1 9 . 0 1 . 6 7 7 5 2 5 . 1 1 . 6 1 4 . 4 1 . 3 0 5 1 1 2 6 . 1 4 . 5 8 . 2 1 . 7 4 9 0 1 4 . 6 2 . . 4 2 2 7 . 6 5 . 9 1 0 . 0 1 . 9 5 5 4 1 6 . 5 2 . 7 2 1 3 2 3 . 7 2 . 5 5 . 5 1 . 3 6 4 6 F E B 1 0 1 1 1 7 . 4 1 4 6 2 0 . 7 2 . 9 4 5 9 2 3 5 . 8 3 1 . 7 4 0 . 5 4 . 2 3 3 4 1 2 1 2 . 3 1 0 . . 0 1 5 . . 2 2 . 4 8 0 2 3 9 . 4 4 . 4 4 2 1 0 . 3 8 . 2 1 2 9 2 . 2 7 0 2 5 6 . 7 5 . 3 3 1 3 9 8 7 . 7 1 2 . 4 2 . 2 1 0 8 2 1 0 . 6 8 . 4 1 3 . . 2 2 . 2 9 9 3 F E B 1 7 1 1 2 7 1 . . 7 4 . . 3 1 . 1 6 7 6 2 1 4 . 0 1 1 . . 5 1 7 . 0 2 . 6 4 2 4 1 2 8 . , 2 6 . 4 1 0 . 6 2 . 0 3 0 5 1 2 . 0 2 . 4 5 2 6 . 6 5 . . 0 8 . 8 1 . 8 2 3 5 2 1 . 1 3 . 2 5 1 3 1 . 1 . 5 2 . . 2 . 7 2 9 4 2 . 5 . 2 1 . . 5 . 5 1 5 8 F E B 2 4 1 1 9 . 4 7 . . 4 1 2 . 0 2 . 1 7 2 9 2 3 . 8 2 . 6 5 . 5 1 . 3 7 6 7 1 2 1 . 9 1 . 1 3 . 3 . 9 8 2 0 1 1 . 8 2 . 4 3 2 . 3 . 1 1 . 2 . 4 0 7 7 4 . 6 1 . 5 1 1 3 . 4 . 1 1 . 3 . 4 4 6 7 2 . 5 . 1 1 . 4 . 4 8 2 4 152 M A R M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 1 . 3 . 6 2 . 4 . 7 9 4 8 2 2 . 3 1 . 4 3 . 7 1 . 0 6 3 2 1 2 . 3 . 1 1 . 2 . 4 0 7 7 1 . 9 . 9 8 2 . 6 . 2 1 . 6 . 5 4 7 0 3 . 0 1 . 2 2 1 3 . 3 . 1 1 . 2 . 4 0 7 7 2 . 1 . 0 . 9 . 2 5 7 9 M A R 1 0 1 2 1 2 1 2 M A R 1 7 1 1 4 2 . 4 3 7 . 9 4 7 . 3 4 . 6 0 2 2 2 8 6 . 1 7 9 . 7 9 3 . 1 6 . 5 6 1 9 1 2 1 2 . 5 9 . 3 1 6 . 8 2 . 5 0 4 9 5 7 . 7 5 . 3 7 2 5 . 7 3 . 7 8 . 9 1 . 6 9 4 2 9 2 3 6 . . 7 9 1 3 2 . 8 1 . 4 5 . 3 1 . 1 8 4 0 2 . 4 . 0 2 . 0 . 4 4 7 5 1 1 5 2 . 2 4 5 . 3 6 0 . 2 5 . 1 0 8 7 2 6 3 . 5 5 5 . 8 7 2 . 3 5 . 6 3 6 8 1 2 3 5 . 0 2 9 . 4 4 1 . 6 4 . 1 8 1 9 9 1 . . 3 6 . 7 6 2 2 4 . 8 2 0 . 1 3 0 . 6 3 . 5 2 3 6 9 0 . . 4 6 . 7 2 1 3 4 . 1 2 . 4 6 . 9 1 . 4 3 8 5 2 2 . 0 . 9 4 . . 2 1 . 0 0 0 6 1 1 9 8 . . 3 8 4 . 9 1 1 3 . 9 7 . 0 1 2 1 2 8 7 . 1 7 4 . . 5 1 0 1 . 9 6 . . 6 0 1 0 1 2 1 6 . . 8 1 1 . . 6 2 4 . . 1 2 . . 8 9 7 4 1 4 2 . 6 8 . 4 4 2 1 4 . 9 1 0 . 1 2 1 9 2 . 7 3 1 7 1 1 8 . 6 7 . 7 0 1 3 2 7 . 4 2 0 . 7 3 6 , 3 3 . 7 0 4 7 2 1 6 . 5 1 1 . 4 2 3 . . 8 2 . 8 7 4 3 1 1 1 7 3 . 8 1 5 5 . . 6 1 9 4 . 0 9 . 3 2 0 9 2 1 2 8 . . 5 1 1 3 . 0 1 4 6 . 0 8 . 0 1 4 1 1 2 2 2 . . 4 1 6 . . 3 3 0 . . 6 3 . . 3 4 5 6 2 0 1 . 5 1 0 . . 0 4 2 6 9 . . 3 5 8 . 1 8 2 . . 6 5 . 8 8 6 0 3 5 5 . 0 1 3 . . 3 2 1 3 5 . . 3 2 . 7 1 0 . . 2 1 . . 6 3 2 5 2 1 5 7 2 1 4 0 . , 0 1 7 6 . 5 8 . 8 6 6 7 1 1 4 5 8 3 6 . . 9 5 6 . 9 4 . 7 8 7 4 2 1 2 7 . 4 1 1 2 . 0 1 4 4 . 9 7 . . 9 8 0 8 1 2 5 4 . . 9 4 5 0 6 6 . 9 5 2 3 9 2 2 0 9 . 2 1 0 . 2 3 2 2 5 1 . . 3 2 2 9 . . 4 2 7 5 . 3 1 1 . . 2 0 9 6 4 5 6 . 5 1 5 . 1 1 1 3 1 0 8 . . 5 9 4 . . 3 1 2 4 . 7 7 . 3 6 4 3 2 7 7 . 8 6 5 . 9 9 1 . 8 6 . 2 3 7 7 1 1 8 9 . 0 7 6 . 2 1 0 3 . 9 6 . 6 7 1 2 2 7 3 . 6 6 2 . O 8 7 . 2 6 . 0 6 4 4 1 2 1 3 1 . 7 1 1 6 . 0 1 4 9 . 4 8 . 1 1 3 3 3 6 5 . 6 1 3 . 5 2 2 1 7 1 . 4 1 5 3 . 4 1 9 1 . 4 9 . 2 5 6 3 4 1 0 . 3 1 4 . 3 2 1 3 1 4 5 . 0 1 2 8 . 5 1 6 3 . 5 8 . 5 1 4 0 2 1 6 5 . 4 1 4 0 . 8 1 9 4 . 1 9 . 0 9 3 5 1 1 7 6 . 8 6 5 . 0 9 0 . 6 6 . 1 9 4 8 2 1 7 3 . 8 1 5 5 . 6 1 9 4 . 0 9 . 3 2 0 9 1 2 8 6 . 3 7 3 . 8 1 0 1 . 0 6 . 5 7 0 6 8 5 9 . 8 2 0 . 7 3 2 8 7 . 7 7 5 . 0 1 0 2 . 4 6 . 6 2 1 1 3 9 6 . 9 1 4 . 0 9 1 3 6 9 6 . 8 6 4 4 . 8 7 5 2 . 8 1 8 . 6 6 4 8 2 1 3 5 . 5 1 1 3 . 4 1 6 1 . 8 8 . 2 3 1 3 1 53 D A P H N I A L O N G I S P I N A 9 5 % C . I . L O W E R U P P E R D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . J A N 6 1 1 . 9 . O 8 . 0 . 5 4 4 3 2 . 2 . 0 6 . 8 . 2 7 2 1 1 2 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 2 3 . 1 2 . 7 8 2 2 . 9 . 5 1 1 . 1 . 9 8 1 2 1 8 . 9 2 . 5 1 1 3 1 9 . 1 1 0 . 9 3 2 . 7 2 . 5 2 3 6 2 1 5 . 8 8 . 5 2 8 . 5 2 . 2 9 3 0 J A N 1 3 1 1 4 . 9 1 . 4 1 4 . 1 1 . 2 7 6 4 2 4 . 0 1 . 0 1 2 . 8 1 . 1 5 4 6 1 2 1 0 . 9 5 . 1 2 2 . 2 1 . 9 0 4 9 3 0 . 4 3 . 1 9 2 1 3 . 3 6 . 8 2 5 . 4 2 . 1 0 7 9 3 2 . 7 3 . 3 0 1 3 1 4 . 7 7 . 7 2 7 . 1 2 . 2 1 0 8 2 1 5 . 3 8 . 2 2 8 . 0 2 . 2 6 0 5 J A N 2 0 1 1 1 4 . 4 7 . 5 2 6 . 8 2 . 1 9 4 0 2 4 . 5 1 . 3 1 3 . 5 1 . 2 2 9 1 1 2 1 5 . 1 8 . 0 2 7 . 7 2 . 2 4 4 1 3 7 . 3 3 . 5 3 2 8 . 0 3 . 2 1 8 . 4 1 . 6 3 2 8 1 7 . 2 2 . 3 9 1 3 7 . 8 3 . 1 1 8 . 1 1 . 6 1 0 0 2 4 . 7 1 . 3 1 3 . 7 1 . 2 4 7 1 J A N 2 7 1 1 2 . 9 . 5 1 1 . 1 . 9 8 1 2 2 3 5 . 3 2 3 . 6 5 2 . 4 3 . 4 3 1 4 1 2 1 6 . 4 9 . 0 2 9 . 4 2 . 3 4 1 0 3 3 . 1 3 . 3 2 2 2 8 . 2 1 7 . 9 4 3 . 9 3 . 0 6 6 8 7 2 . 0 4 . 9 0 1 3 1 3 . 8 7 . 1 2 6 . 0 2 . 1 4 2 8 2 8 . 4 3 . 5 1 9 . 0 1 . 6 7 7 5 F E B 3 1 1 1 2 . 9 6 . 4 2 4 . 8 2 . 0 7 2 5 2 4 . . 7 1 . . 3 1 3 . 7 1 . 2 4 7 1 1 2 2 4 . 7 2 1 . 4 2 8 . 6 3 . 5 1 7 0 3 7 . 6 4 . 0 8 2 2 2 . 0 1 8 . 8 2 5 . 7 3 . 3 1 7 5 3 7 . 1 4 . 2 2 1 3 2 1 0 . . 4 8 . . 3 1 3 . . 1 2 . 2 8 4 8 F E B 1 0 1 1 9 , 4 1 . . 9 . 6 5 7 5 2 1 9 1 . . 1 3 . . 2 . 9 6 4 9 1 2 1 . 2 6 2 . . 4 . 7 7 3 6 1 8 . 0 3 . 0 0 2 4 . 0 2 . . 7 5 . . 8 1 . 4 1 2 4 4 8 . 9 4 . 9 4 1 3 1 5 . 9 1 3 . 2 1 9 . 1 2 . 8 1 9 0 2 4 3 . O 3 8 . . 5 4 8 . 0 4 . 6 3 8 2 F E B 1 7 1 1 3 . 4 2 . 3 5 . 1 1 . 3 0 2 2 2 3 . 9 2 . 6 5 . 6 1 . 3 8 8 7 1 2 4 . 3 3 . 0 6 . 2 1 . 4 7 0 1 1 6 . 8 2 . 9 0 2 4 4 . 3 3 9 . 7 4 9 . 4 4 . 7 0 5 8 7 1 . 7 5 . 9 9 1 3 9 . 1 7 . 1 1 1 . 6 2 . 1 3 4 3 2 2 3 . 5 2 0 . 3 2 7 . 3 3 . 4 3 0 8 F E B 2 4 1 1 4 2 . 8 3 8 . 3 4 7 . 8 4 . 6 2 3 8 2 1 1 . 0 8. 8 1 3 . 8 2 . 3 4 9 4 1 2 1 5 . 4 1 2 . 7 1 8 . . 5 2 . 7 7 1 4 6 7 . 8 5 . 8 2 2 1 2 . O 9 . 7 1 4 . 9 2 . 4 5 3 2 2 8 . 2 3 . 7 5 1 3 9 . 6 7 . 6 1 2 . 2 2 . 1 9 5 7 2 5 . 1 3 . 7 7 . 1 1 . 6 0 0 1 1 54 M A R 1 1 1 6 . 7 1 4 . . 0 2 0 . 0 2 . 8 8 8 9 2 4 . . 3 3 . 0 6 . . 1 1 . 4 5 8 8 1 2 4 9 . . 9 4 5 . . 1 5 5 . 3 4 . 9 9 7 1 7 8 . 9 6 . 2 8 2 1 3 . . 7 1 1 . . 2 1 6 . 7 2 . 6 1 7 2 2 6 . 1 3 . . 6 1 1 3 1 2 . 2 9 , . 9 1 5 . 1 2 . 4 7 3 5 2 8 . . 2 6 . , 3 1 0 . 6 2 . 0 2 2 3 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 1 9 . 4 1 6 . 5 2 2 . 9 3 . 1 1 5 9 2 2 0 . 7 1 7 . 7 2 4 . 3 3 . 2 2 0 9 1 2 2 5 . 9 2 1 . 1 3 1 . 7 3 . 5 9 8 5 5 9 . 9 5 . 4 7 2 1 3 2 . 4 1 2 1 . 2 1 4 4 . 8 8 . 1 3 7 3 1 9 5 . 8 9 . 8 9 1 3 1 4 . 6 1 1 . 0 1 9 . 1 2 . 6 9 7 4 2 4 2 . 6 3 6 . 3 4 9 . 9 4 . 6 1 4 5 1 1 1 2 . 5 9 . 3 1 6 . 8 2 . 5 0 4 9 2 8 6 . 8 7 7 . 7 9 6 . 9 6 . 5 8 6 9 1 2 2 3 . 5 1 9 . 0 2 9 . 1 3 . 4 2 7 5 5 0 . . 9 5 . 0 4 2 5 2 . 1 4 5 . 1 6 0 . 0 5 . 1 0 2 2 1 6 1 . 3 8 . 9 8 1 3 1 4 . 8 1 1 . 3 1 9 . 4 2 . 7 2 2 0 2 2 2 . 4 1 8 . 0 2 7 . 9 3 . 3 4 8 7 1 1 3 0 . 6 2 3 . 4 4 0 . 0 3 . 9 1 4 6 2 1 2 6 . . 3 1 1 1 . 0 1 4 3 . 7 7 . 9 4 7 4 1 2 2 2 . 4 1 6 . 3 3 0 . 6 3 . 3 4 5 6 9 8 . 1 7 . 0 0 2 1 2 . 3 8 . 0 1 8 . 7 2 . 4 7 5 8 1 4 6 . 6 8 . 5 6 1 3 4 5 . 0 3 6 . 2 5 6 . 0 4 . 7 4 5 4 2 8 . 0 4 . 6 1 3 . 5 1 . 9 9 9 4 1 1 3 6 . 5 2 8 . 6 4 6 , . 5 4 . 2 7 2 6 2 2 3 . , 5 1 7 . 2 3 1 . 8 3 . 4 2 4 3 1 2 4 3 . . 4 3 4 . 7 5 4 . . 2 4 . 6 6 0 4 9 7 . . 5 6 . 9 8 2 3 7 . 0 2 9 . 1 4 7 . . 1 4 , . 3 0 3 7 7 0 . . 1 5 . 9 2 1 3 1 7 . 6 1 2 . 3 2 5 . 0 2 . 9 6 5 6 2 9 , . 6 5 . 9 1 5 . 5 2 . 1 9 0 2 1 1 1 4 . . 1 9 . 5 2 0 , , 9 2 . 6 5 7 5 2 3 8 . . 9 3 0 . 7 4 9 , . 2 4 . 4 1 0 7 1 2 1 8 . 7 1 3 . 2 2 6 , . 3 3 , . 0 5 4 1 5 0 . . 9 5 . 0 4 2 4 6 . . 4 3 7 . 4 5 7 . . 5 4 8 1 5 1 1 0 1 . . 3 7 . 1 2 1 3 1 8 . 1 1 2 . 7 2 5 , 6 3 , , 0 1 0 1 2 1 6 0 1 1 . 0 2 3 . . 1 2 . 8 2 7 5 1 1 5 . 9 3 . 1 1 0 . 8 1 . 7 1 2 2 2 1 4 . , 1 9 . 5 2 0 . . 9 2 , . 6 5 7 5 1 2 9 . 3 5 . 7 1 5 . 2 2 . 1 5 9 6 2 7 . 2 3 . 6 9 2 2 1 . 9 1 5 . 9 3 0 O 3 . 3 0 5 5 4 5 . 6 4 . 7 7 1 3 1 2 . 0 7 . 7 1 8 . 4 2 . 4 4 8 7 2 9 . 6 4 . 7 1 9 O 2 . 1 9 1 2 1 1 1 8 . 9 1 3 . 4 2 6 6 3 . 0 7 5 8 2 4 6 . . 9 3 7 . 8 5 8 , , 1 4 . 8 4 2 7 1 2 2 0 . . 0 1 4 . 3 2 7 , 8 3 . 1 6 1 3 5 4 . . 9 5 . . 2 4 2 6 . 1 3 . 3 1 1 , 2 1 , , 7 5 0 6 5 3 . 6 5 . . 1 8 1 3 1 6 . 0 9 . 3 2 7 . , 1 2 . . 8 2 8 9 2 5 , 0 6 . 1 5 1 6 5 155 D I A C Y C L O P S T H O M A S S I 9 5 % C . I . L O W E R U P P E R D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ! S . E . J A N 6 1 1 2 . 2 . 3 1 0 . 1 . 8 6 0 6 2 . 9 . 0 8 . 0 . 5 4 4 3 1 2 . 4 . 0 7 . 2 . 3 8 4 9 4 . 4 1 . 2 2 2 4 . 2 1 . 1 1 3 . 1 1 . 1 8 6 2 1 4 . 7 2 . 2 1 1 3 1 . 8 . 1 9 . 4 . 7 6 9 7 2 9 . G 4 . 2 2 0 . 5 1 . 7 8 4 5 J A N 1 3 1 1 5 . 1 1 . 6 1 4 . 4 1 . 3 0 5 1 2 8 . 0 3 . 2 1 8 . 4 1 . 6 3 2 8 1 2 6 . 9 2 . 6 1 6 . 9 1 . 5 1 5 2 2 0 . 9 2 . 6 4 2 8 . 0 3 . 2 1 8 . 4 1 . 6 3 2 8 2 0 . 7 2 . 6 2 1 3 8 . 9 3 . 8 1 9 . 6 1 . 7 2 1 1 2 4 . 7 1 . 3 1 3 . 7 1 . 2 4 7 1 J A N 2 0 1 1 4 . 0 1 . 0 1 2 8 1 . 1 5 4 6 2 4 O 1 . 0 1 2 . 8 1 . 1 5 4 6 1 2 4 . 4 1 . 2 1 3 . . 4 1 . 2 1 7 0 1 3 . 1 2 . 0 9 2 8 . 7 3 . 6 1 9 . . 3 1 . 6 9 9 5 1 6 . 2 2 . 3 3 1 3 4 . 7 1 . 3 1 3 . . 7 1 . 2 4 7 1 2 3 . 6 . 8 1 2 , . 1 1 . 0 8 8 5 J A N 2 7 1 1 G . 0 2 O 1 5 . 6 1 . 4 1 4 0 2 8 . 7 3 . 6 1 9 . . 3 1 . 6 9 9 5 1 2 G . 4 2 . 3 1 6 . 2 1 . 4 6 5 5 2 2 . 0 2 . 7 1 2 7 . 6 3 . 0 1 7 . . 8 1 . 5 8 6 8 2 0 , . 7 2 . 6 2 1 3 9 . 6 4 . 2 2 0 . , 5 1 . 7 8 4 5 2 4 . 4 1 . 2 1 3 . . 4 1 . 2 1 7 0 F E B 3 1 1 7 . 8 3 . 1 1 8 . . 1 1 . 6 1 0 0 2 G . 9 2 . 6 1 6 . 9 1 . 5 1 5 2 1 2 9 . 0 7 . 0 1 1 . . 5 2 . 1 1 8 7 1 6 . 8 2 . 6 6 2 7 . 6 5 . 8 9 . . 9 1 . 9 4 6 9 1 8 . . 9 2 . 8 8 1 3 2 4 . 5 3 . 1 6 . . 3 1 . 4 9 2 6 F E B 1 0 1 1 2 . 2 1 . 3 3 . 6 1 . 0 4 7 5 2 3 . 9 2 . 7 5 . . 7 1 . 4 0 0 6 1 2 3 . 8 2 . G 5 . 5 1 . 3 7 6 7 2 4 . 1 3 . 4 7 2 3 . 4 2 . . 3 5 . 1 1 . 3 0 2 2 2 2 . 0 3 . . 3 2 1 3 1 8 . . 2 1 5 . . 3 2 1 . 5 3 . 0 1 2 8 2 1 4 . . 7 1 2 . . 1 1 7 . 8 2 . 7 1 0 8 F E B 1 7 1 1 3 . . 9 2 . . 6 5 . 6 1 . 3 8 8 7 2 5 . 5 4 . . 0 7 . 6 1 . 6 6 1 2 1 2 5 . . 8 4 . . 2 7 . 9 1 . 7 0 0 8 3 0 . 5 3 . 9 0 2 1 5 . . 2 1 2 . . 6 1 8 . 3 2 . 7 5 3 4 5 3 . 1 5 . . 1 5 1 3 2 0 . . 8 1 7 . . 7 2 4 . 4 3 . 2 2 6 0 2 3 2 . . 5 2 8 . . 6 3 6 . 9 4 . 0 2 8 2 F E B 2 4 1 1 8 . . 0 6 . 2 1 0 . 4 2 . 0 0 5 8 2 8 . . 7 6 . 8 1 1 . 2 2 . 0 8 7 0 1 2 G 3 4 . 6 8 . 4 1 . 7 6 7 9 2 4 . 7 3 . . 5 2 2 8 . 8 6 . 9 1 1 . 3 2 . 1 0 2 9 2 4 . 0 3 . 4 6 1 3 1 0 . 4 8 . 3 1 3 . 1 2 . 2 8 4 8 2 6 . 5 4 . 8 8 . 6 1 . . 7 9 5 9 1 56 M A R 1 1 2 1 . 4 1 8 , , 3 2 5 . , 1 3 . 2 7 2 1 2 1 0 . 6 8 . 4 1 3 . . 2 2 . 2 9 9 3 1 2 8 . 4 6 . 5 1 0 . , 9 2 . 0 5 4 9 3 8 . 0 4 . 3 6 2 9 . . 0 7 0 1 1 . , 5 2 . 1 1 8 7 2 4 . 3 3 . . 4 8 1 3 8 . 2 6 . . 3 1 0 , . 6 2 . 0 2 2 3 2 4 . . 7 3 . . 3 6 , . 6 1 . 5 3 6 5 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 2 2 . 1 1 8 . . 9 2 5 . . 8 3 . 3 2 2 5 2 2 4 . 7 2 1 . 4 2 8 . 6 3 . 5 1 7 0 1 2 1 9 . 1 1 5 . . 0 2 4 . 2 3 . 0 8 9 5 6 4 . . 3 5 . 6 7 2 1 3 . 6 1 0 . . 2 1 8 . . 1 2 . 6 0 9 3 5 5 . 0 5 . 2 5 1 3 2 3 . 1 1 8 . 6 2 8 . 7 3 . 3 9 8 2 2 1 6 . 7 1 2 . 9 2 1 , . 5 2 . 8 8 8 6 1 1 3 5 . 4 2 9 . 7 4 2 . . 1 4 . 2 0 5 8 2 3 0 . 6 2 5 . . 3 3 6 9 3 . 9 0 9 7 1 2 2 1 . 5 1 7 . . 2 2 6 . . 9 3 . 2 7 8 2 8 0 . 4 6 . 3 4 2 3 2 . 3 2 6 . 9 3 8 . 7 4 . 0 1 9 1 8 4 . . 6 6 . . 5 1 1 3 2 3 . 5 1 9 O 2 9 . 1 3 . 4 2 7 5 2 2 1 . 8 1 7 . 4 2 7 . 2 3 . 2 9 8 5 1 1 3 5 . 2 2 7 . 4 4 5 . 1 4 . 1 9 3 9 2 2 7 . 2 2 0 . 4 3 6 . 0 3 . 6 8 6 7 1 2 3 4 . 1 2 6 . 5 4 3 . 9 4 . 1 2 9 9 1 8 5 . 2 9 . 6 2 2 1 0 . 7 6 . 7 1 6 . 8 2 . 3 0 8 7 4 6 . 9 4 . 8 4 1 3 1 1 5 . 9 1 0 1 . 3 1 3 2 . 7 7 . 6 1 3 4 2 9 . 1 5 . 4 1 4 . 8 2 . 1 2 8 5 1 1 3 5 . 4 2 7 . 7 4 5 . 3 4 . 2 0 9 8 2 3 8 . 6 3 0 . 5 4 8 . 9 4 . 3 9 5 6 1 2 2 8 . 0 2 1 . 1 3 6 . 9 3 . 7 4 0 5 7 6 . 5 6 . 1 8 2 1 4 . 1 9 . 5 2 0 . 9 2 . 6 5 7 5 5 9 . 7 5 . 4 6 1 3 1 3 . 1 8 . 6 1 9 . 7 2 . 5 5 5 2 2 6 . 9 3 . 8 1 2 . 2 1 . 8 6 1 3 1 1 3 0 . 1 2 3 . 0 3 9 . 4 3 . 8 8 0 4 2 3 1 . 2 2 3 . 9 4 0 . 6 3 . 9 4 8 4 1 2 3 4 . 6 2 6 . 9 4 4 . 5 4 . 1 6 2 0 9 4 . 6 6 . 8 8 2 3 1 . 2 2 3 . 9 4 0 . 6 3 . 9 4 8 4 8 2 . 6 6 . 4 3 1 3 2 9 . 8 2 2 . 8 3 9 . 1 3 . 8 6 3 2 2 2 0 . 3 1 4 . 5 2 8 . 1 3 . 1 8 2 3 1 1 7 7 . 3 6 5 . 4 9 1 . 2 6 . 2 1 6 3 2 8 2 . 3 7 0 . 1 9 6 . 7 6 . 4 1 6 7 1 2 9 8 . 1 8 4 . 6 1 1 3 . 6 7 . 0 0 2 6 2 9 4 . 5 1 2 . 1 3 2 7 2 . 5 6 1 . . 0 8 6 , 0 6 . 0 2 0 3 2 3 8 . 1 1 0 . 9 1 1 3 1 1 9 . 1 1 0 4 . 2 1 3 6 . 1 7 . 7 1 7 7 2 8 3 . 2 6 6 . 2 1 0 4 . 5 6 . 4 5 0 8 1 1 9 6 . 2 8 2 . 9 1 1 1 . 6 6 . 9 3 5 7 2 7 4 . 9 6 3 . 2 8 8 . 6 6 . 1 1 9 1 1 2 6 7 . 2 5 6 . 2 8 0 . 2 5 . 7 9 4 7 2 3 0 . 6 1 0 . 7 4 1 6 2 . 6 5 2 . 0 7 5 . 3 5 . 5 9 5 9 1 9 0 . 3 9 . 7 6 1 3 6 7 . 2 5 2 . 1 8 6 . 6 5 . 7 9 7 5 2 5 2 . 8 3 9 . 5 7 0 . 3 5 . 1 3 8 9 157 D I A P T O M U S S P . 9 5 % C . I . L O W E R U P P E R D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . J A N 6 1 1 . 4 . 0 7 . 2 . 3 8 4 9 2 . 4 . 0 7 . 2 . 3 8 4 9 1 2 . 9 . 0 8 . 0 . 5 4 4 3 3 . 1 1 . 0 2 2 1 . 1 . 0 8 . 3 . 6 0 8 5 1 3 . 3 2 . 1 1 1 3 1 . 8 . 1 9 . 4 . 7 6 9 7 2 1 1 . 8 5 . 7 2 3 . 4 1 . 9 8 1 1 J A N 1 3 1 1 . 9 . 0 8 . 0 . 5 4 4 3 2 3 . 6 . 8 1 2 . 1 1 . 0 8 8 5 1 2 1 . 1 . 0 8 . 3 . 6 0 8 5 3 . 3 1 . 0 5 2 2 . 7 . 4 1 0 . 8 . 9 4 2 7 8 . 6 1 . 6 9 1 3 1 . 3 . 0 8 . 7 . 6 6 6 6 2 2 . 3 . 3 1 0 . 3 . 8 8 1 8 J A N 2 0 1 1 2 . 0 . 2 9 . 8 . 8 1 6 4 2 . 8 . 0 7 . 8 . 5 1 6 3 1 2 4 . 2 1 . 1 1 3 . 1 1 . 1 8 6 2 7 . 6 1 . 5 9 2 2 . 0 . 2 9 . 8 . 8 1 6 4 7 . 2 1 . 5 5 1 3 1 . 3 . 0 8 . 7 . 6 6 6 6 2 4 . 4 1 . 2 1 3 . 4 1 . 2 1 7 0 J A N 2 7 1 1 2 . 7 . 4 1 0 . 8 . 9 4 2 7 2 4 . 0 1 . 0 1 2 . 8 1 . 1 5 4 6 1 2 2 . 9 . 5 1 1 . 1 . 9 8 1 2 6 . 4 1 . 4 7 2 4 . 0 1 . 0 1 2 . 8 1 . 1 5 4 6 8 . 7 1 . 7 0 1 3 . 9 . 0 8 . 0 . 5 4 4 3 2 . 7 . 1 7 . 6 . 4 7 1 3 F E B 3 1 1 1 . 3 . 0 8 . 7 . 6 6 6 6 2 . 7 . 1 7 . 6 . 4 7 1 3 1 2 1 . 5 . 8 2 . 7 . 8 5 5 3 2 . 8 1 . 0 8 2 1 . 4 . 7 2 . 6 . 8 3 5 6 2 . 8 1 . 1 3 1 3 - - - -2 . 7 . 3 1 . 7 . 6 0 4 8 F E B 1 0 1 1 . 4 . 1 1 . 3 . 4 4 6 7 2 . 4 . 1 1 . 3 . 4 4 6 7 1 2 . 9 . 4 2 . 0 . 6 8 2 3 2 . 7 1 . 1 5 2 . 7 . 2 1 . 7 . 5 7 6 6 6 . 8 1 . 8 5 1 3 1 . 3 . 7 2 . 5 . 8 1 5 5 2 5 . 8 4 . 2 7 . 9 1 . 7 0 0 8 F E B 1 7 1 1 . 6 . 2 1 . 6 . 5 4 7 0 2 . 5 . 2 1 . 5 . 5 1 5 8 1 2 . 5 . 2 1 . 5 . 5 1 5 8 1 . 4 . 8 4 2 1 . 1 . 5 2 . 2 . 7 2 9 4 3 . 1 1 . . 2 5 1 3 . 3 . 0 1 . 1 . 3 6 4 7 2 1 . 5 . 8 2 . 8 . 8 7 4 5 F E B 2 4 1 1 1 . 1 . 5 2 . 3 . 7 5 1 8 2 . 3 . 0 1 . 1 . 3 6 4 7 1 2 . 3 . 0 1 . 1 . 3 6 4 7 1 . 7 . 9 1 2 . 2 . 0 1 . 0 . 3 1 5 8 . 5 . 4 8 1 3 . 3 . 0 •1 . 1 . 3 6 4 7 2 0 . . 0 . 6 0 . 158 M A R 3 1 1 . 3 . 0 1 . 1 . 3 6 4 7 2 . 1 . 0 . 8 . 1 8 2 3 1 2 . 4 . 1 1 . 3 . 4 4 6 7 1 . 4 . 8 4 2 . 6 . 2 1 . 6 . 5 4 7 0 . 8 . 6 3 1 3 . 7 . 3 1 . 7 . 6 0 4 8 2 . 1 . O . 9 . 2 5 7 9 M A R 1 0 1 1 - - -2 - - -1 2 - - - -2 - - - -1 3 - - -2 - - -M A R 1 7 1 1 . 5 . 2 1 . 5 . 5 1 5 8 2 . 5 . 2 1 . 5 . 5 1 5 8 1 2 . 1 . 0 1 . 5 . 2 5 8 4 1 . 3 . 8 2 2 . 9 . 3 2 . 8 . 6 8 3 6 3 . 7 1 . 3 7 1 3 . 7 . 1 2 . 4 . 5 7 7 7 2 2 . 3 1 . 1 4 . 6 1 . 0 6 5 2 M A R 2 4 1 1 2 . 9 1 . 5 5 . 4 1 . 2 1 1 8 2 4 . 4 2 . 6 7 . 3 1 . 4 8 4 2 1 2 . 7 . 1 2 . 4 . 5 7 7 7 4 . 3 1 . 4 6 2 . 9 . 3 2 . 8 . 6 8 3 6 6 . 1 1 . 7 5 1 3 . 7 . 1 2 . 4 . 5 7 7 7 2 . 8 . 2 2 . 6 . 6 3 2 9 M A R 3 1 1 1 5 . 3 2 . 7 1 0 . 2 1 . 6 3 2 5 2 8 . 3 4 . 8 1 3 . 9 2 . 0 3 2 4 1 2 1 . 3 . 3 4 . 7 . 8 1 6 2 1 6 . 8 2 . 9 0 2 1 . 1 . 2 4 . 3 . 7 3 0 1 1 0 . 9 2 . 3 4 1 3 1 0 . 1 6 . 3 1 6 . 1 2 . 2 5 0 2 2 1 . 6 . 4 5 . 1 . 8 9 4 1 A P R 7 1 1 1 5 . 7 1 0 . 8 2 2 . 8 2 . 8 0 3 9 2 1 2 . 8 8 . 4 1 9 . 4 2 . 5 2 9 0 1 2 1 . 6 . 4 5 . 1 . 8 9 4 1 1 7 . 6 2 . 9 7 2 . 3 . 0 3 . 0 . 3 6 5 0 1 3 . 1 2 . 5 6 1 3 . 3 . 0 3 . 0 . 3 6 5 0 2 0 . . 0 2 . 6 O . A P R 1 4 1 1 1 0 . 1 6 . 3 1 6 . 1 2 . 2 5 0 2 V \ 2 5 . 6 2 . 9 1 0 . 5 1 . 6 7 2 8 ) 1 2 1 . 6 . 4 5 . 1 . 8 9 4 1 1 3 . 9 2 . 6 3 2 . 8 . 1 3 . 9 . 6 3 2 3 6 . 4 1 . 7 9 1 3 2 . 1 . 7 5 . 9 1 . 0 3 2 5 2 0 . . 0 2 . 6 0 . A P R 2 1 1 1 3 . 7 1 . 6 8 . 1 1 . 3 6 5 8 2 1 7 . 6 1 2 . 3 2 5 . 0 2 . 9 6 5 6 1 2 2 . 1 . 7 5 . 9 1 . 0 3 2 5 7 . 5 1 . 9 3 2 6 . 1 3 . 3 1 1 . 2 1 . 7 5 0 6 2 4 . 8 3 . 5 2 1 3 1 . 6 . 4 5 . 1 . 8 9 4 1 2 1 . 1 . 0 7 . 0 . 7 3 0 4 A P R 2 8 1 1 8 . 5 5 . 0 1 4 . 2 2 . 0 G 4 9 2 8 . 0 4 . 6 1 3 . . 5 1 . 9 9 9 4 1 2 1 2 . 5 8 . 2 1 9 . 0 2 . 5 0 2 5 2 8 . 5 3 . 7 8 2 1 0 . 9 6 . 9 1 7 . . 1 2 . 3 3 7 4 2 1 . 1 3 . 2 4 1 3 7 . 5 3 . 3 1 6 . . 1 1 . 9 3 2 5 2 2 . 1 . 3 8 . 6 1 . 0 3 3 0 159 K E L L I C O T T I A B O S T O N I E N S I S 9 5 % C . I . L O W E R U P P E R T O T A L D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m 1 S . E J A N 6 1 1 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 2 2 . 4 . 3 1 0 . 4 . 9 0 2 6 1 2 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 1 4 . 0 2 . 1 6 2 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 1 2 . 7 2 . 0 5 1 3 7 . 8 3 . 1 1 8 . 1 1 . 6 1 0 0 2 7 . 1 2 . 7 1 7 . 2 1 . 5 3 9 4 J A N 1 3 1 1 . 2 . 0 6 . 8 . 2 7 2 1 2 2 . 2 . 3 1 0 . 1 . 8 6 0 6 1 2 1 . 8 . 1 9 . 4 . 7 6 9 7 6 . 7 1 . 4 9 2 1 . 6 . 1 9 . 0 . 7 2 0 0 6 . 4 1 . 4 7 1 3 4 . 7 1 . 3 1 3 . 7 1 . 2 4 7 1 2 2 . 7 . 4 1 0 . 8 . 9 4 2 7 J A N 2 0 1 1 2 . 2 . 3 1 0 . 1 . 8 6 0 6 2 . 3 . 0 6 . 9 . 2 9 8 1 1 2 1 . 3 . 0 8 . 7 . 6 6 6 6 6 . 4 1 . 4 7 2 3 . 8 . 9 1 2 . 4 1 . 1 2 2 0 6 . 7 1 . 5 0 1 3 2 . 9 . 5 1 1 . 1 . 9 8 1 2 2 2 . 7 . 4 1 0 . 8 . 9 4 2 7 J A N 2 7 1 1 2 . 9 . 5 1 1 . 1 . 9 8 1 2 2 . 2 . 0 6 . 8 . 2 7 2 1 1 2 2 . 0 . 2 9 . 8 . 8 1 6 4 7 . 3 1 . 5 6 2 2 . 7 . 4 1 0 . 8 . 9 4 2 7 6 . 9 1 . 5 2 1 3 2 . 4 . 3 1 0 . 4 . 9 0 2 6 2 4 . 0 1 . O 1 2 . 8 1 . 1 5 4 6 F E B 3 1 1 3 . 3 . 7 1 1 . 8 1 . 0 5 4 0 2 3 . 8 . 9 1 2 . 4 1 . 1 2 2 0 1 2 2 . 9 1 . 9 4 . 5 1 . 2 0 9 5 6 . 3 1 . 6 0 2 3 . 3 2 . 2 5 . 0 1 . 2 8 9 4 1 1 . 2 2 . 2 2 1 3 - - - -2 4 . 1 2 . 8 5 . 9 1 . 4 2 4 2 F E B 1 0 1 1 1 . 2 . 6 2 . 4 . 7 7 3 6 2 . 9 . 4 2 . 0 . . 6 8 2 3 1 2 1 . 6 . 9 2 . 9 . 8 9 3 3 4 . 6 1 . 5 1 2 1 . 2 . 6 2 . 4 . 7 7 3 6 3 . 9 1 . 3 9 1 3 1 . 8 . 1 . 0 3 . 1 . 9 4 7 5 2 1 . 7 1 . 0 3 . 0 . 9 2 9 8 F E B 1 7 1 1 . 2 . 0 1 . 0 . 3 1 5 8 2 . 8 . 3 1 . 8 . 6 3 1 7 1 2 . 5 . 2 1 . 5 . 5 1 5 8 7 . 1 1 . 8 9 2 . 3 . O 1 . 1 . 3 6 4 7 1 3 . 5 2 . , 6 0 1 3 6 . 4 4 . 8 8 . 5 1 . 7 8 6 6 2 1 2 . 4 1 0 . 1 1 5 . 3 2 . 4 9 3 5 F E B 2 4 1 1 . 5 . 2 1 . 5 . 5 1 5 8 2 . 7 . 2 1 . 7 . 5 7 6 6 1 2 . 2 . 0 1 . 0 . 3 1 5 8 3 . 2 1 . 2 6 2 . 3 . 1 1 . 2 . 4 0 7 7 7 . 2 1 . 8 9 1 3 2 . 5 1 . 5 3 . 9 1 . 1 0 9 2 2 6 . 2 4 . 6 8 . 3 1 . 7 5 8 5 160 M A R 1 1 4 3 3 . 0 6 . 2 1 . 4 7 0 1 2 2 . 1 1 . 2 3 . 5 1 . 0 1 5 3 1 2 1 . 5 . 8 2 . 8 . 8 7 4 5 7 . 8 1 . 9 7 2 5 . 1 3 . 6 7 . 0 1 . 5 8 9 7 1 1 . 1 2 . 3 6 1 3 1 . 9 1 . 1 3 . 3 . 9 8 2 0 2 4 . 0 2 . 7 5 . . 8 1 . 4 1 2 4 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 1 . 0 . 4 2 . 1 . 7 0 6 2 2 1 . 5 . 8 2 . 8 . 8 7 4 5 1 2 4 . 1 2 . 4 6 . 9 1 . 4 3 8 5 1 3 . 8 2 . 6 3 2 2 . 1 1 . 0 4 . 4 1 . 0 3 3 4 8 . 9 2 . 1 1 1 3 8 . 7 6 . 1 1 2 . 4 2 . 0 8 3 0 2 5 . 2 3 . 2 8 . 3 1 . 6 1 3 5 1 1 2 . 5 1 . 3 4 . 9 1 . 1 2 6 2 2 2 . 4 1 . 2 4 . 7 1 . 0 9 6 1 1 2 7 . 6 5 . 2 1 1 . 1 1 . 9 5 0 6 2 5 . . 8 3 . 5 9 2 7 3 . 3 6 5 . 0 8 2 . 6 6 . 0 5 3 6 1 0 1 . 6 7 . 1 3 1 3 1 5 . 6 1 2 . 0 2 0 . 3 2 . 7 9 4 6 2 2 5 . 9 2 1 . 1 3 1 . 7 3 . 5 9 8 5 1 1 8 . 3 4 . 8 1 3 . . 9 2 . 0 3 2 4 2 3 . 2 1 . 3 7 . 3 1 . 2 6 4 5 1 2 1 5 . 2 1 0 . 3 2 2 . 2 2 . 7 5 5 9 6 6 . . 4 5 . 7 6 2 2 0 . 3 1 4 . 5 2 8 . 1 3 . 1 8 2 3 5 8 . 6 5 . 4 1 1 3 4 2 . 9 3 4 . . 3 5 3 . 7 4 . 6 3 1 8 2 3 5 . 2 2 7 . 4 4 5 . . 1 4 . 1 9 3 9 1 1 6 . 9 3 . . 8 1 2 . 2 1 8 6 1 3 2 1 1 . . 7 7 . . 5 1 8 . . 1 2 . 4 2 1 4 1 2 3 1 . . 2 2 3 . . 9 4 0 . . 6 3 . . 9 4 8 4 9 4 . 1 6 . 8 6 2 5 6 . 0 4 6 . . 0 6 8 . 0 5 . 2 8 9 8 1 1 4 . 3 7 . . 5 6 1 3 5 6 . 0 4 6 . . 0 6 8 . 0 5 . 2 8 9 8 2 4 6 . . 6 3 7 . 6 5 7 . 8 4 . . 8 2 8 9 1 1 7 . 2 4 . 0 1 2 . 5 1 . . 8 9 6 8 2 1 8 . 4 1 3 . 0 2 5 . 9 3 . 0 3 2 2 1 2 1 0 0 . 5 8 6 . 9 1 1 6 . 2 7 . 0 8 7 7 4 0 6 . 9 1 4 . 2 6 2 1 7 0 . 0 1 5 2 . 1 1 9 0 . 0 9 . 2 2 0 3 3 7 2 . 8 1 3 . 6 5 1 3 2 9 9 . 3 2 7 5 . 3 3 2 5 . 4 1 2 2 3 2 7 2 1 8 4 . 4 1 6 5 . 7 2 0 5 . 2 9 . 6 0 2 6 1 1 1 4 . 4 9 . 7 2 1 . 3 2 . 6 8 2 4 2 3 7 . 8 2 9 . 8 4 8 . 0 4 . 3 4 9 9 1 2 1 3 6 . 4 1 2 0 . 5 1 5 4 . 5 8 . 2 5 9 8 3 0 5 . 9 1 2 . 3 7 2 1 4 2 . 0 1 2 5 . 7 1 6 0 . 4 8 . 4 2 7 5 4 6 0 . 5 1 5 . 1 7 1 3 1 5 5 . 1 1 3 8 . 0 1 7 4 . 3 8 . 8 0 6 3 2 2 8 0 . 6 2 4 8 . 2 3 1 7 . 2 1 1 . 8 4 5 3 1 1 1 0 . 4 6 . 5 1 6 . 5 2 . 2 7 9 6 2 1 4 . 1 9 . 5 2 0 . 9 2 . 6 5 7 5 1 2 2 8 . 8 2 1 . 8 3 7 . . 9 3 . 7 9 3 5 8 2 . . 9 6 . 4 4 2 4 2 . 4 3 3 8 5 3 . 1 4 . 6 0 2 9 8 4 . 2 6 . 4 9 1 3 4 3 . 7 3 1 8 6 0 . 0 4 . 6 7 6 9 2 2 7 . 7 1 8 , . 5 4 1 . . 3 3 . 7 2 4 4 161 K E R A T E L L A C R A S S A 9 5 % C . I . L O W E R U P P E R T O T A L D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N 0 / 1 O O c m ' S . E . J A N 6 1 1 0 . . 0 6 . 4 O . 2 0 . . 0 6 . 4 0 . 1 2 0 . . 0 6 . 4 O . O . 0 . 2 O . . 0 6 . 4 0 . O . 0 . 1 3 0 . . 0 6 . 4 0 . 2 0 . . 0 6 . 4 0 . J A N 1 3 1 1 O . . 0 6 . 4 0 . 2 . 4 . 0 7 . 2 . 3 8 4 9 1 2 0 . . 0 6 . 4 0 . O . 0 . 2 0 . . 0 6 . 4 0 . . 4 . 3 8 1 3 0 . . 0 6 . 4 0 . 2 O . . 0 6 . 4 0 . J A N 2 0 1 1 O . . 0 6 . 4 0 . 2 . 3 . 0 6 . 9 . 2 9 8 1 1 2 0 . . 0 6 . 4 0 . . 4 . 3 8 2 O . . 0 6 . 4 O . . 5 . 4 0 1 3 . 4 . 0 7 . 2 . 3 8 4 9 2 . 2 . 0 6 . 8 . 2 7 2 1 J A N 2 7 1 1 . 2 . O 6 . 8 . 2 7 2 1 2 O . . 0 6 . 4 0 . 1 2 . 9 . O 8 . 0 . 5 4 4 3 2 . 2 . 8 6 2 O . . 0 6 . 4 0 . . 9 . 5 4 1 3 1 . 1 . 0 8 . 3 . 6 0 8 5 2 . 9 . 0 8 . 0 . 5 4 4 3 F E B 3 1 1 . 9 . O 8 . 0 . 5 4 4 3 2 0 . . 0 6 . 4 0 . 1 2 . 3 . 1 1 . 2 . 4 0 7 7 1 . 2 . 6 8 2 . 1 . 0 . 9 . 2 5 7 9 . 8 . 6 3 1 3 -2 . 7 . 2 1 . 7 . 5 7 6 6 F E B 1 0 1 1 . 2 . 0 1 . 0 . 3 1 5 8 2 . 2 . 0 1 . 0 . 3 1 5 8 1 2 . 6 . 2 1 . 6 . 5 4 7 0 1 . 3 . 7 9 2 . 7 . 2 1 . 7 . 5 7 6 6 1 . 1 . 7 3 1 3 . 5 . 1 1 . 4 . 4 8 2 4 2 . 2 . 0 1 . 0 . 3 1 5 8 F E B 1 7 1 1 . 2 . 0 1 . 0 . 3 1 5 8 2 0 . . O . 6 O . 1 2 . 1 . 0 . 8 1 8 2 3 3 . 5 1 . 3 1 2 0 . . 0 . 6 0 . 2 . 7 1 . 1 5 1 3 3 . 2 2 . 1 4 . 8 1 . 2 6 3 3 2 2 . 7 1 . 7 4 . 2 1 . 1 5 3 3 F E B 2 4 1 1 . 1 . 0 . 8 . 1 8 2 3 2 . 1 . 0 . 8 . 1 8 2 3 1 2 0 . . 0 . 6 0 . 1 . 1 . 7 5 2 - 1 0 . 8 1 8 2 3 1 . 5 . 8 6 1 3 1 . 1 . 5 2 . 2 . 7 2 9 4 2 1 . 3 . 7 2 . 5 . 8 1 5 5 162 M A R . 3 6 4 7 . 1 8 2 3 0 . . 2 5 7 9 1 . 5 2 5 6 1 . 3 8 8 7 4 . 9 4 . 1 1 . 5 7 1 . 4 2 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 . A P R 2 1 A P R 2 8 1 1 . 1 . 0 . 8 . 1 8 2 3 2 . 9 . 4 1 . 9 . 6 5 7 5 1 2 1 . 2 . 4 3 . 1 . 7 7 5 1 3 1 . 6 3 . 9 7 2 0 . 0 1 . 3 0 5 5 . 6 5 . 2 7 1 3 3 0 . 3 2 5 . 1 3 6 . 6 3 . 8 9 2 6 2 5 4 . 7 4 7 . 6 6 2 . 9 5 . 2 3 1 4 1 1 . 1 . 0 1 . 5 . 2 5 8 4 2 2 . 4 1 . 2 4 . 7 1 . 0 9 6 1 1 2 . 1 . 0 1 . 5 . 2 5 8 4 1 2 6 . 7 7 . 9 6 2 . 8 . 2 2 . 6 . 6 3 2 9 2 2 2 . 8 1 0 . 5 5 1 3 1 2 6 . 4 1 1 5 . 4 1 3 8 . 5 7 . 9 5 0 6 2 2 1 9 . 6 2 0 5 . 0 2 3 5 . 3 1 0 . 4 7 8 7 1 1 1 . 9 . 5 5 . 5 . 9 6 5 8 2 . 5 . 0 3 . 5 . 5 1 6 2 1 2 1 1 . 7 7 . 5 1 8 . 1 2 . 4 2 1 4 5 6 . O 5 . 2 9 2 2 . 1 . 7 5 . 9 1 . 0 3 2 5 5 . 9 1 . 7 1 1 3 4 2 . 4 3 3 . 8 5 3 . 1 4 . 6 0 2 9 2 3 . 2 1 . 3 7 . 3 1 . 2 6 4 5 1 1 O . O 2 . 6 0 2 0 . 0 2 . 6 0 1 2 . 5 . 0 3 . 5 . 5 1 6 2 5 6 . 5 5 . 3 1 2 1 . 3 . 3 4 . . 7 . 8 1 6 2 3 8 . . 9 4 . 4 1 1 3 5 6 . 0 4 6 . 0 6 8 . 0 5 . 2 8 9 8 2 3 7 . 6 2 9 . 5 4 7 . 7 4 . 3 3 4 5 1 1 0 . 0 2 . 6 0 2 4 . . 3 2 . O 8 . 8 1 . 4 6 0 1 1 2 2 . 4 . 8 6 . . 2 1 . 0 9 5 1 1 4 8 . 2 8 . 6 1 2 2 . 9 1 . 1 7 , . 0 1 . 2 1 0 7 4 0 . . 8 4 . 5 2 1 3 1 4 5 . . 8 1 2 9 . 2 1 6 4 . . 4 8 . 5 3 7 4 2 3 3 6 2 6 . 0 4 3 . 3 4 . . 0 9 7 5 1 1 0 . . 0 2 . 6 0 . 2 9 . 6 5 . 9 1 5 . . 5 2 1 9 0 2 1 2 0 . . 0 2 . . 6 0 . 1 1 9 . 9 7 . . 7 4 2 5 . 0 3 . 5 . 5 1 6 2 1 2 2 . 2 7 . 8 2 1 3 1 1 9 . 9 1 0 5 . . 0 1 3 6 . 9 7 . . 7 4 3 5 2 1 1 2 . O 9 2 . . 1 1 3 6 . 2 7 . 4 8 4 5 1 1 0 . . 0 2 . 6 0 . 2 1 . 1 2 4 . 3 7 3 0 1 1 2 0 . 0 2 . 6 0 . 6 8 . 3 5 . 8 4 2 8 1 3 . 9 6 3 2 3 3 2 . 3 4 . 0 2 1 3 6 8 . 3 5 3 . 0 8 7 . 8 5 . 8 4 3 3 2 3 0 . 4 2 0 . 7 4 4 . 4 3 . 8 9 9 3 163 K E R A T E L L A Q U A O R A T A L O W E R U P P E R T O T A L D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . E . J A N 6 1 1 1 9 . 1 1 0 . 9 3 2 . 7 2 . 5 2 3 6 2 2 . 9 . 5 1 1 . 1 . 9 8 1 2 1 2 1 0 . 4 4 . 8 2 1 . 6 1 . 8 6 5 6 3 6 . 4 3 . 4 8 2 3 . 1 . 6 1 1 . 5 1 . 0 1 8 2 1 1 . 8 1 . 9 8 1 3 6 . 9 2 . 6 1 6 . 9 1 . 5 1 5 2 2 5 . 8 1 . 9 1 5 . 3 1 . 3 8 7 6 J A N 1 3 1 1 . 9 . 0 8 . 0 . 5 4 4 3 2 2 . 2 . 3 1 0 . 1 . 8 6 0 6 1 2 1 . 1 . 0 8 . 3 . 6 0 8 5 6 . 0 1 . 4 1 2 1 . 6 . 1 9 . 0 . 7 2 0 0 5 . 8 1 . 3 9 1 3 4 . 0 1 . 0 1 2 . 8 1 . 1 5 4 6 2 2 . 0 . 2 9 . 8 . 8 1 6 4 J A N 2 0 1 1 . 2 . 0 6 . 8 . 2 7 2 1 2 . 3 . 0 6 . 9 . 2 9 8 1 1 2 . 2 . 0 6 . 8 . 2 7 2 1 2 . 2 . 8 6 2 1 . 1 . 0 8 . 3 . 6 0 8 5 2 . 0 ' . 8 3 1 3 1 . 8 . 1 9 . 4 . 7 6 9 7 2 . 7 . 1 7 . 6 . 4 7 1 3 J A N 2 7 1 1 . 4 . 0 7 . . 2 . 3 8 4 9 2 . 9 . 0 8 . 0 . 5 4 4 3 1 2 1 . 3 . 0 8 . 7 . 6 6 6 6 3 . 1 1 . 0 2 2 3 . 3 . 7 1 1 . 8 1 . 0 5 4 0 5 . 8 1 . 3 9 1 3 1 . . 3 . 0 8 . . 7 . 6 6 6 6 2 1 . e . 1 9 . 0 . 7 2 0 0 F E B 3 1 1 1 . 8 . 1 9 . 4 . 7 6 9 7 2 2 . 0 . 2 9 . 8 . 8 1 6 4 1 2 1 . . 3 . 7 2 . 5 . 8 1 5 5 3 . 1 1 . 1 2 2 2 . 4 1 . 5 3 . 9 1 . 0 9 4 1 6 . 7 1 . 7 4 1 3 - -2 2 . . 3 1 . 4 3 . 8 1 . 0 7 8 8 F E B 1 0 1 1 . 4 . 1 1 . 3 . 4 4 6 7 2 1 . . 2 . 6 2 . . 4 . 7 7 3 6 1 2 1 . . 1 . 5 2 . . 3 . 7 5 1 8 2 . 3 1 . 0 6 2 1 . . 4 . 7 2 . 6 . 8 3 5 6 3 . 1 1 . 2 5 1 3 7 . 3 1 . . 7 . 6 0 4 8 2 . 5 . 2 1 , . 5 . 5 1 5 8 F E B 1 7 1 1 1 . . 7 1 . 0 3 . 0 . 9 2 9 8 2 1 . . 1 . 5 2 . 3 . 7 5 1 8 1 2 8 . 9 7 . 0 1 1 . . 4 2 . 1 1 0 8 1 1 . 6 2 . . 4 1 2 1 . . 2 . 6 2 . . 4 . 7 7 3 6 3 . 2 1 . 2 6 1 3 1 . 0 . 4 2 . 1 . 7 0 6 2 2 9 . 4 1 . 9 . 6 5 7 5 F E B 2 4 1 1 6 . 2 1 . 6 . 5 4 7 0 2 1 . 3 . 6 2 . 4 . 7 9 4 8 1 2 2 . 0 1 . 0 . 3 1 5 8 1 . 5 8 6 2 1 . 1 . 5 2 . 2 . 7 2 9 4 3 . 2 1 . . 2 6 1 3 . 7 . 2 1 . 7 . 5 7 6 6 2 9 . 4 1 . 9 . 6 5 7 5 164 M A R 3 1 1 3 . 9 2 . 7 5 . 7 1 . 4 0 0 G 2 2 . 1 1 . 2 3 . 5 1 . 0 1 5 3 1 2 1 . 5 . 8 2 . 8 . 8 7 4 5 7 . 6 1 . 9 5 2 2 . 5 1 . 5 3 . 9 1 . 1 0 9 2 5 . 9 1 . 7 2 1 3 2 . 1 1 . 3 3 . 5 1 . 0 3 1 5 2 1 . 4 . 7 2 . 6 . 8 3 5 6 M A R 1 0 1 1 - - -2 -1 2 -2 - - -1 3 -2 -M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 4 . 3 3 . O 6 . 2 1 . 4 7 0 1 2 2 . 5 1 . 6 4 . . 0 1 . , 1 2 4 1 1 2 1 . 5 . 6 3 . . 5 . 8 5 6 9 8 . 1 2 . 0 1 2 1 . . 1 . 3 2 . 9 . 7 3 0 8 4 . 7 1 . 5 3 1 3 2 . 3 1 . 1 4 . 6 1 . 0 6 5 2 2 1 . . 1 . 3 2 . , 9 , 7 3 0 8 1 1 9 . 9 7 . 1 1 3 . . 8 2 . 2 2 2 5 2 3 . . 9 2 . 2 6 6 1 . . 3 9 1 3 1 2 1 . 5 . 6 3 . 5 . 8 5 6 9 1 2 . 8 2 . 5 3 2 4 . . 0 2 . 3 6 . 8 1 . 4 1 5 1 8 . 7 2 . 0 8 1 3 1 . . 5 . 6 3 . . 5 . 8 5 6 9 2 8 . 2 2 . . 6 . 6 3 2 9 1 1 9 . 1 5 . 4 1 4 . 8 2 . 1 2 8 5 2 4 . . 5 2 . 2 9 . 1 1 . . 5 0 5 1 1 2 5 . . 6 2 . 9 1 0 . . 5 1 . . 6 7 2 8 2 5 . 6 3 . 5 8 2 3 . 7 1 . . 6 8 . 1 1 . 3 6 5 8 1 0 . , 4 2 . 2 8 1 3 1 0 . 9 6 . . 9 1 7 . 1 2 . 3 3 7 4 2 2 . 1 . 7 5 . 9 1 . 0 3 2 5 1 1 2 1 . 1 1 5 . 2 2 9 . . 0 3 . 2 4 4 5 2 2 2 . 7 1 6 . 6 3 0 . 9 3 . 3 6 5 4 1 2 5 . 1 2 . 5 9 . 8 1 . , 5 9 1 1 2 7 . 7 3 . 7 2 2 8 . 0 4 . . 6 1 3 . 5 1 . 9 9 9 4 3 2 . 5 4 , . 0 3 1 3 1 . 6 . 4 5 . 1 8 9 4 1 2 1 . 9 . 5 5 . 5 9 6 5 8 1 1 3 0 . 1 2 3 . . 0 3 9 . 4 3 . 8 8 0 4 2 5 1 . 2 4 1 . . 7 6 2 . 8 5 . 0 5 8 1 1 2 1 0 . 7 6 . , 7 1 6 . 8 2 . 3 0 8 7 4 5 . 0 4 . 7 5 2 9 . 1 5 . . 4 1 4 . 8 2 . 1 2 8 5 6 6 . 6 5 . . 7 7 1 3 4 . 3 2 . 0 8 . 8 1 . 4 6 0 1 2 6 . 4 3 . 5 1 1 . 5 1 . 7 8 8 3 1 1 3 1 . 4 2 4 . 1 4 0 . 9 3 . 9 6 5 3 2 4 4 . 8 3 5 . 9 5 5 . 7 4 . 7 3 1 4 1 2 2 6 . 6 2 0 . 0 3 5 . 4 3 . 6 5 0 3 7 3 . 8 6 . 0 8 2 2 3 . 2 1 7 . 0 3 1 . 5 3 . 4 0 4 8 8 2 . 9 6 . 4 4 1 3 1 5 . 7 1 0 . 8 2 2 . 8 2 . 8 0 3 9 2 1 4 . 9 8 . 5 2 5 . 8 2 . 7 3 2 9 1 1 4 6 . 9 3 7 . 8 5 8 . 1 4 . 8 4 2 7 2 7 0 . 1 5 8 . 8 8 3 . 4 5 . 9 1 9 9 1 2 2 5 . 1 1 8 . 6 3 3 . 6 3 . 5 3 9 1 1 0 2 . 9 7 . 1 7 2 3 1 . 4 2 4 . 1 4 0 . 9 3 . 9 6 5 3 1 1 9 . 1 7 . 7 2 1 3 3 0 . 9 2 1 . 1 4 5 . 1 3 . 9 3 3 4 2 1 7 . 6 1 0 . 5 2 9 . 1 2 . 9 6 6 9 165 N A U P L I I 9 5 % C . I . L O W E R U P P E R T O T A L D A T E S T N D E P T H N O / L L I M I T L I M I T S . E . N O / 1 0 0 c m ' S . . E . J A N 6 1 1 3 . e . 8 1 2 . 1 1 . 0 8 8 5 2 2 . 0 . 2 9 . 8 . 8 1 6 4 1 2 3 . 8 . 9 1 2 . 4 1 . 1 2 2 0 1 4 . 2 2 . 1 7 7 1 2 4 . 2 1 . 1 1 3 . 1 1 . 1 8 6 2 1 4 . 2 2 . 1 7 7 1 1 3 6 . 9 2 . 6 1 6 . 9 1 . 5 1 5 2 2 8 . 0 3 . 2 1 8 . 4 1 . 6 3 2 8 1 1 5 . 3 1 . 7 1 4 . 7 1 . 3 3 3 2 2 8 . 2 3 . 4 1 8 . 7 1 . 6 5 5 3 1 2 1 9 . 1 1 0 . . 9 3 2 . 7 2 . 5 2 3 6 3 8 . 2 3 . 5 6 9 0 2 4 6 . 0 3 2 . 4 6 4 . 9 3 . 9 1 5 3 6 1 . 5 4 . 5 2 9 2 1 3 1 3 . 8 7 . 1 2 6 . 0 2 . 1 4 2 8 2 7 . 3 2 . . 8 1 7 . 5 1 > . 5 6 3 3 1 1 1 1 . 6 5 . . 5 2 3 . 1 1 . 9 6 2 4 2 4 0 1 . . 0 1 2 . 8 1 . 1 5 4 6 1 2 8 . 9 3 8 1 9 . 6 1 . 7 2 1 1 4 1 . . 5 3 . 7 2 1 3 2 1 9 8 1 1 . . 4 3 3 . 6 2 . 5 6 7 3 6 3 . . 3 4 . . 5 9 4 1 1 3 2 1 . 1 1 2 . . 4 3 5 . 2 2 . 6 5 2 4 2 3 9 . 5 2 7 . . 1 5 7 . 4 3 . 6 3 0 7 1 1 1 8 . 7 1 0 . 6 3 2 . 2 2 . 4 9 4 1 2 1 2 6 . 4 1 6 . 5 4 1 . 7 2 . 9 6 8 6 1 2 5 1 . 8 3 7 . 3 7 1 . 6 4 . 1 5 3 9 2 6 2 . 8 9 3 5 9 9 2 1 9 . 8 1 1 , 4 3 3 . 6 2 . 5 6 7 3 9 6 . . 9 5 . . 6 8 2 3 1 3 1 9 2 . 4 1 6 2 . 8 2 2 7 . 2 8 . 0 0 8 3 2 5 0 . . 7 3 6 . . 3 7 0 . . 3 4 . 1 0 9 1 1 1 6 2 . 9 4 6 . 7 8 4 . 3 4 . 5 7 8 0 2 4 0 . 4 2 7 . . 8 5 8 . 4 3 . . 6 7 1 3 1 2 5 3 . 2 4 8 . . 2 5 8 . 7 5 . 1 5 7 5 1 1 6 . 1 6 . . 8 9 6 2 2 3 3 . 9 2 9 , , 9 3 8 . . 4 4 . 1 1 7 9 1 6 6 . 9 8 . 7 5 9 0 1 3 - - -2 9 2 . 6 8 5 . 9 9 9 . 8 6 . 8 0 3 2 1 1 2 4 . 9 2 1 . 5 2 8 . 8 3 . . 5 2 6 4 2 2 2 . 9 1 9 . 6 2 6 . 6 3 . 3 8 2 0 1 2 3 8 . 1 3 3 . 9 4 2 . . 9 4 . 3 6 4 9 1 1 5 . 0 7 5 8 2 2 2 2 8 . 8 2 5 . 1 3 3 . 0 3 . 7 9 4 4 9 6 . 4 6 . 9 4 1 1 1 3 5 2 . 0 4 7 . 0 5 7 . 5 5 . 0 9 9 2 2 4 4 . 7 4 0 . . 1 4 9 . . 8 4 . . 7 2 6 9 1 1 7 . 4 5 . 7 9 . 7 1 . 9 2 9 8 2 1 1 . 8 9 . 5 1 4 . 6 2 . 4 2 6 0 1 2 1 1 . 6 9 . 4 1 4 . 4 2 . 4 1 2 2 1 1 3 . 8 7 . 5 4 4 8 2 2 7 . 3 2 3 . 7 3 1 . 3 3 . 6 9 2 2 1 1 0 . 9 7 . 4 4 7 2 1 3 9 4 . 8 8 8 . 0 1 0 2 . 0 6 . 8 8 3 4 2 7 1 . 9 6 6 . 0 7 8 . 3 5 . 9 9 5 3 1 1 1 4 . 7 1 2 . 1 1 7 8 2 . 7 1 0 8 2 1 5 . 3 1 2 . 7 1 8 . 4 2 . 7 6 5 4 1 2 1 1 . 8 9 , . 6 1 4 . . 6 2 . 4 3 2 8 9 4 . 8 6 . 8 8 3 4 2 1 7 . 7 1 4 . . 9 2 1 . , 0 2 . 9 7 4 0 1 2 1 . 9 7 . 8 0 6 9 1 3 6 8 . . 2 6 2 . 5 7 4 . . 5 5 8 4 0 8 2 8 8 . 9 8 2 . 4 9 6 . O 6 . 6 6 7 5 166 M A R 1 1 4 7 . . 6 4 2 . 9 5 2 . 9 4 . 8 7 9 2 2 2 3 . 7 2 0 . 4 2 7 . 6 3 . 4 4 5 3 1 2 3 0 . . 1 2 6 . 4 3 4 . 4 3 . 8 8 1 0 1 9 3 . 4 9 . . 8 3 4 8 2 3 6 . . 6 3 2 . 4 4 1 . 2 4 . 2 7 6 4 1 4 9 . 8 8 . 6 5 5 2 1 3 1 1 5 . . 7 1 0 8 . 2 1 2 3 . 7 7 . 6 0 6 2 2 8 9 . . 5 8 2 . 9 9 6 . 6 6 . 6 8 9 9 M A R 1 0 M A R 1 7 M A R 2 4 M A R 3 1 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 2 9 . . 7 2 6 . 0 3 3 . 9 3 . . 8 5 0 9 2 3 3 . . 5 2 9 . 6 3 8 . , 0 4 . . 0 9 3 7 1 2 3 3 . 9 2 8 . 4 4 0 . . 5 4 . . 1 1 7 6 2 2 5 . . 2 1 0 . 6 1 2 2 2 2 9 . . 6 2 4 . 5 3 5 8 3 . . 8 4 9 5 2 9 5 . 8 1 2 . 1 6 2 3 1 3 1 6 1 . 7 1 4 9 . 2 1 7 5 . 2 8 . 9 9 0 8 2 2 3 2 . 7 2 1 7 . 6 2 4 8 . 8 1 0 . 7 8 6 3 1 1 6 8 . 5 6 0 . , 5 7 7 . 5 5 . 8 5 1 7 2 4 7 . 5 4 0 . 9 5 5 . 2 4 . 8 7 4 7 1 2 8 7 . 4 7 8 . 3 9 7 . 6 6 . 6 1 2 2 4 5 0 . 6 1 5 . . 0 0 9 4 2 8 4 . 1 7 5 . 2 9 4 . . 1 6 . 4 8 4 8 6 1 8 . 9 1 7 . . 5 9 1 3 1 3 2 9 4 . . 6 2 7 7 . . 6 3 1 2 . 7 1 2 . 1 3 7 4 2 4 8 7 . 3 4 6 5 . . 3 5 1 0 . 3 1 5 . . 6 0 8 9 1 1 7 5 . . 4 6 3 . 7 8 9 . 2 6 1 4 0 8 2 5 0 . . 9 4 1 . 4 6 2 . . 5 5 . . 0 4 4 9 1 2 1 5 6 . . 4 1 3 9 . 3 1 7 5 . . 7 8 . 8 4 4 1 4 5 8 9 1 5 . 1 4 7 8 2 1 5 1 . 4 1 3 4 . 5 1 7 0 . . 3 8 6 9 9 8 3 2 9 . 7 1 2 . . 8 3 8 6 1 3 2 2 7 . 1 2 0 6 . 2 2 4 9 . 9 1 0 . 6 5 5 0 2 1 2 7 . 4 1 1 2 . . 0 1 4 4 . 9 7 . 9 8 0 8 1 1 1 7 1 . 6 1 5 3 . 6 1 9 1 . 7 9 . 2 6 3 5 2 1 5 9 . 9 1 4 2 . 5 1 7 9 . 3 8 . . 9 4 1 5 1 2 2 3 8 . . 5 2 1 7 . 2 2 6 1 . 9 1 0 . 9 2 0 6 7 8 5 . 4 1 9 . 8 1 6 4 2 1 8 4 . 2 1 6 5 . 5 2 0 4 . . 9 9 . . 5 9 5 6 6 6 6 . , 8 1 8 . 2 5 9 0 1 3 3 7 5 . 2 3 4 8 . . 3 4 0 4 . 3 1 3 . 6 9 7 3 2 3 2 2 . . 7 2 9 7 . . 8 3 4 9 . 8 1 2 . . 7 0 3 0 1 1 2 4 0 . . 1 2 1 8 . 7 2 6 3 . . 6 1 0 . . 9 5 7 1 2 2 4 4 , . 6 2 2 3 . 0 2 6 8 . . 4 1 1 . . 0 6 0 0 1 2 2 9 3 . 9 2 7 0 . 2 3 1 9 . 8 1 2 . 1 2 3 3 1 0 7 8 5 2 3 . 2 2 2 0 2 3 1 2 . 3 2 8 7 . 8 3 3 8 . 9 1 2 . 4 9 6 8 7 6 9 . 1 1 9 . 6 1 0 2 1 3 5 4 4 . 5 5 1 1 . 8 5 7 9 . 2 1 6 . 4 9 9 4 2 2 1 2 . 1 1 9 2 . O 2 3 4 . 3 1 0 . 2 9 8 9 1 1 1 5 8 . 6 1 4 1 . . 3 1 7 7 . 9 8 . . 9 0 4 1 2 2 1 1 . . 1 1 9 1 . . 0 2 3 3 . , 2 1 0 . . 2 7 3 0 1 2 2 5 8 . 8 2 3 6 . 5 2 8 3 . 1 1 1 . 3 7 4 8 9 5 3 . 8 2 1 . 8 3 8 1 2 2 5 4 . 0 2 3 1 . 9 2 7 8 . 1 1 1 . 2 6 8 9 8 2 6 . 8 2 0 . 3 3 1 7 1 3 5 3 6 . 5 5 0 4 . 1 5 7 0 . 9 1 6 . 3 7 7 8 2 3 6 1 . 7 3 2 4 . 7 4 0 2 . 9 1 3 . 4 4 8 3 1 1 9 6 . 7 8 3 . 4 1 1 2 . 2 6 . 9 5 4 8 2 9 9 . 4 8 5 . 9 1 1 5 . 0 7 . 0 5 0 0 1 2 1 8 0 . 2 1 6 1 . 7 2 0 0 . 7 9 . 4 9 0 9 9 4 8 . 0 2 1 . 7 7 2 0 2 2 6 0 . 6 2 3 8 . 3 2 8 5 . 1 1 1 . 4 1 5 7 8 6 9 . 5 2 O . 8 5 1 1 1 3 6 7 1 . 1 6 2 0 . 2 7 2 6 . 2 1 8 . 3 1 8 6 2 5 0 9 . 5 4 6 5 . 3 5 5 7 . . 8 1 5 . 9 6 0 8 167 P O L V A R T H R A S P D A T E J A N 6 S T N 1 2 1 2 1 2 D E P T H 1 N O / L . 4 0 . 0 . . 4 . 2 . 2 9 5 % L O W E R L I M I T . 0 . 0 . 0 . 0 . 0 . 0 C . I U P P E R L I M I T 7 . 2 S . E . . 3 8 4 9 0 . 0 . . 3 8 4 9 . 2 7 2 1 . 2 7 2 1 T O T A L N O / 1 0 0 c m ' S . E . . 7 . 4 7 . 7 . 4 7 J A N 1 3 J A N 2 0 J A N 2 7 F E B F E B 1 0 F E B 1 7 F E B 2 4 1 1 0 . . 0 6 . . 4 0 . 2 0 . . 0 6 . . 4 0 . 1 2 0 . . 0 6 , , 4 0 . . 2 2 7 2 0 . . 0 6 . . 4 0 . 0 0 . 1 3 2 . 0 6 . . 8 2 7 2 1 2 0 . . 0 6 . . 4 0 . 1 1 0 . . 0 6 . . 4 0 . 2 3 . 0 6 . . 9 2 9 8 1 1 2 0 . . O e . . 4 0 . O 0 . 2 0 . . 0 G. . 4 0 . . 3 . 3 0 1 3 0 . . 0 6 . . 4 0 . 2 0 . . 0 6 . 4 0 . 1 1 0 . . 0 6 . 4 0 . 2 4 . 0 7 . . 2 3 8 4 9 1 2 7 . 1 7 . 6 4 7 1 3 . 9 . 5 4 2 4 . O 7 . . 2 3 8 4 9 . 9 . 5 4 1 3 2 . 0 6 . 8 2 7 2 1 2 0 . . 0 6 . 4 0 . 1 1 0 . . 0 6 . . 4 0 . 2 1 . 1 . 0 8 . 3 6 0 8 5 1 2 1 . 0 . 9 2 5 7 9 . 1 . 2 6 2 0 . . 0 . 6 O . 1 . 1 . 6 1 1 3 -2 o . . 0 . G 0 . 1 1 9 . 4 1 . 9 6 5 7 5 2 1 . 7 . 9 3 . 0 . 9 1 1 7 1 2 9 . 4 2 . 0 . 6 8 2 3 1 . 9 . 9 6 2 8 . 3 1 . 8 6 3 1 7 2 . 5 1 . 1 1 1 3 1 . 0 . 8 1 8 2 3 2 0 . . O . 6 0 . 1 1 7 . 3 1 . 7 6 0 4 8 2 8 . 3 1 . 8 . 6 3 1 7 1 2 8 . 3 1 . 8 . 6 3 1 7 1 . 7 . 9 3 2 0 . . 0 ' . 6 0 . 8 . 6 3 1 3 . 2 . 0 1 . 0 . 3 1 5 8 2 0 . . 0 . 6 0 . 1 1 . 5 . 2 1 . 5 . 5 1 5 8 2 . 5 . 1 1 . 4 . 4 8 2 4 1 2 . 1 . O . 9 . 2 5 7 9 . 8 . 6 3 2 . 1 . 0 . 8 . 1 8 2 3 . 6 . 5 5 1 3 . 1 . 0 . 9 . 2 5 7 9 2 . 1 . 0 . 8 1 8 2 3 168 M A R . 5 1 . 1 . 2 . 2 . 1 . 1 . 1 . 5 . 0 . 0 . 0 . O . 4 8 2 4 . 7 2 9 4 . 3 1 5 8 . 3 1 5 8 . 1 8 2 3 . 2 5 7 9 . 7 1 . 4 . 6 0 . 8 4 M A R 1 0 M A R 1 7 M A R 2 4 M A R 1 3 A P R A P R 1 4 A P R 2 1 A P R 2 8 1 1 7 3 1 . . 7 6 0 4 8 2 0 . 0 . 6 0 1 2 4 0 2 . 0 4 4 7 5 1 . 3 2 0 . 0 1 . 3 0 . . 1 1 3 1 0 1 . 5 2 5 8 1 2 1 0 1 . 5 2 5 8 4 1 1 7 . 5 5 . 1 1 1 . O 1 . 9 3 3 4 2 3 . 5 1 . 9 6 . 1 1 . 3 1 7 4 1 2 8 2 2 . 6 6 3 2 9 8 7 2 2 1 . 7 7 3 9 9 3 1 5 5 . 6 1 1 3 4 0 2 . . 0 4 4 7 5 2 4 0 2 . 0 4 4 7 5 1 1 1 1 . 7 7 . 5 1 8 1 2 4 2 1 4 2 4 . 3 2 . 0 8 8 1 . 4 6 0 1 1 2 1 . 6 4 5 . . 1 8 9 4 1 1 4 . 7 2 2 4 . 3 2 . O 8 . 8 1 . 4 6 0 1 1 1 . . 7 2 1 3 1 . 3 3 4 . 7 8 1 6 2 2 3 . 2 1 . 3 7 . 3 1 . 2 6 4 5 1 1 3 3 . 3 2 5 . 8 4 3 . 0 4 . 0 8 1 2 2 2 4 . 3 1 7 . 9 3 2 . 7 3 . 4 8 2 2 1 2 1 4 . 7 9 . 9 2 1 . . 6 2 . 7 0 7 2 5 2 . . 2 5 2 2 2 . 7 1 6 . 6 3 0 . 9 3 . 3 6 5 4 5 3 . 0 5 1 3 4 . 3 2 0 8 . 8 1 . 4 6 0 1 2 6 1 3 . 3 1 1 . 2 1 . 7 5 0 6 1 1 2 0 . 0 1 4 . 3 2 7 . 8 3 . 1 6 1 3 2 2 5 . 6 1 9 1 3 4 2 3 5 7 6 6 1 2 3 8 6 3 0 . 5 4 8 9 4 . 3 9 5 6 7 6 2 6 2 4 9 . 8 4 0 . 5 6 1 3 4 . 9 9 1 8 9 7 . . 3 6 1 3 1 7 . 6 1 2 . 3 2 5 0 2 . 9 6 5 6 2 2 1 . 9 1 5 . 9 3 0 0 3 . 3 0 5 5 1 1 9 1 . 7 7 8 . 7 1 0 6 . . 7 6 7 7 0 1 2 1 1 9 . 4 1 0 4 . 5 1 3 6 4 7 . 7 2 6 3 1 2 2 8 . 5 2 1 . 6 3 7 . . 6 3 7 7 5 9 1 8 9 . 2 9 2 3 8 . 4 3 0 . 2 4 8 . 6 4 . 3 8 0 4 2 1 8 . 1 1 0 1 3 6 9 . 0 5 7 . 9 8 2 . 3 5 . 8 7 4 7 2 6 0 . 3 4 6 . 0 7 8 . 8 5 4 9 0 2 1 1 2 2 . 1 1 6 . 1 3 0 . 3 3 . 3 2 5 6 2 2 6 6 2 0 . 0 3 5 . 4 3 . 6 5 0 3 1 2 5 1 . 7 4 2 . 1 6 3 . 4 5 . 0 8 4 3 2 2 8 . 5 1 0 2 6 6 . 9 5 5 . 9 8 0 . 0 5 . 7 8 3 2 3 0 2 . 1 1 2 1 3 1 5 4 . 7 1 3 1 . 0 1 8 2 . 6 8 . 7 9 5 3 2 2 0 8 . 6 1 8 0 . 8 2 4 0 . 5 1 0 . 2 1 2 7 8 0 2 6 0 8 6 7 7 1 4 2 1 1 1 5 1 7 9 7 7 3 169 APPENDIX T - ANALYSIS FOR DIFFERENCES IN COLONY SIZE BETWEEN REPLICATE SAMPLES The results of the single factor one way ANOVA testing for differences in colony size between rep l i c a t e samples is given in th i s appendix. As the variances of the f i r s t and second replicate samples were homogeneous the analysis was carr i e d out on the untransformed data. As i s evident, there were no si g n i f i c a n t differences between the two re p l i c a t e s . U N I V A R I A T E 1 - W A Y A N O V A < 1 > S A M P L E : O N E » S P E C I E S : D . C Y L N < 2 > S A M P L E : T W O * S P E C I E S : D . C Y L N A N A L Y S I S O F V A R I A N C E O F 8 . L O R I C A * N = 2 0 5 5 O U T O F 2 0 5 5 S O U R C E D F S U M O F S O R S M E A N S O R F - S T A T I S T I C S I G N I F B E T W E E N 1 2 0 8 . 6 8 2 0 8 . 6 8 2 . 3 5 6 1 . 1 2 4 9 W I T H I N 2 0 5 3 . 1 8 1 8 4 + 6 8 8 . 5 7 3 T O T A L 2 0 5 4 . 1 B 2 0 5 + 6 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 0 3 3 9 E T A - S O R = . 0 0 1 1 ( V A R C O M P = . 1 1 7 0 1 % V A R A M O N G = . 1 3 ) E Q U A L I T Y O F V A R I A N C E S : D F = 1 . . 1 2 t o 1 1 + 8 F = . 2 0 5 4 6 . 6 5 0 3 S T R A T A N M E A N V A R I A N C E S T D D E V < 1 > 9 9 5 1 4 . 4 1 4 8 9 . 8 6 7 9 . 4 7 9 8 < 2 > 1 0 6 0 1 3 . 7 7 6 8 7 . 3 5 8 9 . 3 4 6 5 G R A N D 2 0 5 5 1 4 . 0 8 5 8 8 . 6 3 1 9 . 4 1 4 4 U N I V A R I A T E 1 - W A Y A N O V A < 1 > S A M P L E : O N E ' S P E C I E S : D . D I V < 2 > S A M P L E : T W O ' S P E C I E S : D . D I V A N A L Y S I S O F V A R I A N C E O F 8 . L O R I C A * N = 1 2 3 8 O U T O F 1 2 3 8 S O U R C E D F S U M O F S O R S M E A N S O R F - S T A T I S T I C S I G N I F B E T W E E N W I T H I N T O T A L 1 2 5 9 . 8 7 2 5 9 . 8 7 2 . 0 1 1 6 . 1 5 6 4 1 2 3 6 . 1 5 9 6 7 + 6 1 2 9 . 1 9 1 2 3 7 . 1 5 9 9 3 + 6 ( R A N D O M E F F E C T S S T A T I S T I C S ) E T A = . 0 4 0 3 E T A - S Q R = . 0 0 1 6 ( V A R C O M P = . 2 1 1 2 7 % V A R A M O N G = . 1 6 ) E Q U A L I T Y O F V A R I A N C E S : D F = 1 , . 4 5 7 3 8 + 7 F = . 7 3 3 3 3 . 3 9 1 8 S T R A T A < 1 > < 2 > N M E A N 6 0 2 1 3 . 7 9 4 6 3 6 1 2 . 8 7 7 V A R I A N C E 1 3 3 . 7 6 1 2 4 . 8 5 S T D D E V 1 1 . 5 6 6 1 1 . 1 7 4 G R A N D 1 2 3 8 1 3 . 3 2 3 1 2 9 . 2 9 1 1 . 3 7 1 170 APPENDIX U - ZOOPLANKTON GUT ANALYSES RESULTS The p r o p o r t i o n of z o o p l a n k t o n i n d i v i d u a l s examined t h a t c o n t a i n e d D i n o b r y o n l o r i c a s a r e d e t a i l e d h e r e . "-" i n d i c t e s no d a t a . i n d i c a t e s t h a t l o r i c a were f o u n d i n t h e g u t s of z o o p l a n k t o n on t h a t d a t e , but t h a t no q u a n t i t a t i v e d a t a were t a k e n . DATE ASP BOS MAR APR 3 10 17 24 31 7 1 4 21 2 8 3/1 1 8/1 1 4 / 5 2 5 / 3 0 DAP 3 / 1 6 2 9 / 5 0 * 9 / 1 4 6 / 6 DIA 1 5 / 2 5 2 3 / 6 3 1 0 / 1 9 1 6 / 4 0 9 / 2 2 TOTAL EXAMINED 5 7 8 6 169 ASP BOS DAP DIA A s p l a n c h n a p r i o d o n t a  Bosmina c o r e g o n i  Daphnia l o n g i s p i n a  D i a c y c l o p s thomasi 171 APPENDIX V - STATION II RESULTS Morphometric variables for Dinobryon colonies and the colony abundances are detailed here for Station II, 1 metre samples. For comparison, colony abundances and morphometric variables for Station I G, H, & P. samples can be found in Appendices S>. CV1 1 ndr 1 cum DATE * 0 0 »/L COLONV COLONY 0 * »/L COLONY COLONY LPC EMPTY STATO BRANCH LENGTH WIOTH LPC EMPTY STATO BRANCH LENGTH WIDTH MAR 3 16 . 7 1.4 0.0 5.3 178 6 63. 1 MEAN _ _ MEAN 1 .86 0.23 0. 0.24 9.95 5 . 19 SE - - - - - - SE 31 31- 31 31 31 31 N - - - - - N MAR 10 - - - _ „ - MEAN _ - - - - MEAN - - - - - - SE - - - - - - SE - * - - - - N - - - - N MAR 17 4 .6 2 . 7 0.0 3 0 102.5 27 . 1 MEAN 21.0 2 6 0.0 6.0 179 2 84. 1 MEAN 0.51 0 45 0. 0. 2  7. 15 2.20 SE 2 .09 0 36 0. 0. 30 9 74 6.92 SE 31 31 31 31 31 31 N 31 31 31 31 31 31 N MAR 24 12.8 3.5 0.0 4 6 174 1 59.6 MEAN 1.7 2.2 0.71 4.7 138 B 73.6 MEAN 1 .96 0.89 0. 0. 35 10.91 8 32 SE 1 .08 0.36 0 26 0.25 7.70 5 . 36 SE18 18 18 18 18 18 N 31 31 31 31 31 31 N MAR 31 23.5 1 .7 0.0 6.0 19 6 87.2 MEAN 19.7 2 6 0.4! 6.0 173.0 83.9 MEAN 1 .9 O. 28 O. 0. 25 7.5 6 . 26 SE 2.30 0.42 0.15 0.2 7 . 15 5. 15 SE 31 31 31 31 31 31 N 31 31 31 31 31 31 N APR 7 20.7 3.7 0 0 5.7 195.5 93.7 MEAN 16 7 2.6 0 19 5.2 157 9 82 9 MEAN 2 . 2  0 85. 0. 0.27 10.52 9.27 SE 2.20 0. 40 .09 0. 25 7.1 8 46 SE31 31 31 31 31 31 N 31 31 31 31 31 31 N APR 14 1.4 3 8 0.0 4.5 136 . 3 57 . 4 MEAN 7.9 2.6 0 32 3.8 11.3 46.3 MEAN 1 . 15 0 43 0. 0.23 7.41 4.20 SE 0.73 0.45 0.03 0.27 6 92 4 . 23 SE 31 30 31 31 31 31 N 31 31 31 31 31 31 N APR 2 1 10.3 6.6 0.0 4.2 135.2 51.6 MEAN 7.7 4.2 0.0 3.8 115.4 53 . 2 MEAN1 .28 1 .07 0. 0. 27 8.86 4 . 37 SE 0.6 0.72 0. 0.27 7.72 4 .68 SE31 31 31 31 31 31 N 31 30 31 31 31 31 N APR 26 9. 1 6 4 0. 4.0 139 2 64.9 MEAN 8.8 3.3 0.0 4.3 141 .6 63 6 MEAN 1 .2 0.93 0. 0.27 14.91 B-51 SE 1.0 0.S6 0. 0.28 9.04 8.8 SE 8 8 8 8 6 a N 12 12 12 12 12 12 N Station II Station I D. cylIndr tcum 95% CONFIDENCE B• c v l i n d r i c u m 95% CONFIDENCE DATE 0/m\ LOWER UPER 5 .E . DATE A/nl LOWER UPER S ELIMIT LIMIT LIMIT LIMIT MAR 3 63.5 61.1 6.0 7 97 MAR 3 59.3 56.0 62.8 7 70 10 - - - 10 - - -17 1.5 1.2 2.0 1 . 2 17 1.2 0.9 1.7 1 10 24 0. 1 0.06 0. 15 032 24 0.5 0.30 0 76 071 31 o . s O 3 0 7 0 87 31 12 0 9 1 .6 1 10 APR 7 2 4 2.0 3.0 1 5 APR 7 16.7 15.0 18.6 1 .10 14 9 7 8.7 10.7 3 .1 14 21 .9 19.9 24 . 1 468 21 1.5 1.2 2.0 1 . 2 21 1.8 1 .4 2.3 1 34 2B 0.04 0.04 0.06 0. 20 28 0.07 0.04 0. 1 1 0.27D. d Wrp«na 95% CONFIDENCE D. dlvrfltna 95% CONFIDENCE DATE A/ml LOWER UPER S .E . DATE A/ml LOWER UPER S E. LIMIT LIMIT LIMIT LIMT MAR 3 0.03 0.01 0 15 0. 17 MAR 3 0 02 0 OG 0.06 0 .14 10 - - - 10 - - -17 7 0 6.2 7 9 2. 65 17 4.7 4 . 1 5.4 2 17 24 2.3 1 .9 2.8 1 . 52 24 16 4 15. 1 17.8 4. OS 31 15 9 14.7 17.2 3 B 31 28 8 27.2 30 6 5 38 APR 7 4.5 42 5 46.2 6 67 APR 7 115 9 11.2 120.7 10 .7 14 19.2 17.9 2 0 6 4 38 14 4 3 0 40 2 46.2 6 56 21 4 . 1 3.5 4 8 203 21 10 9 9.9 12.0 3 30 28 0.07 0.04 0.6 0. 27 28 0 09 0.05 0. 15 030 1 72 APPENDIX W - RESULTS OF WEIGHTED DATA ANALYSIS A lim i t e d portion of the data was reanalyzed to evaluate the e f f e c t of weighting estimates at each depth by the proportion of the t o t a l lake volume occupied by the strata they represented. The colony size and density estimates of both Dinobryon species and the density estimates of Diacyclops thomasi, Daphnia longispina and Bosmina coregoni were reanalyzed, for each week from week 4 of March to week 4 of A p r i l . A l l density estimates per depth were multiplied by the volume of the strata which they represented, (e.g. 1m - 0-1.5m, 51,983 m3; 2m - 1.5-2.5m, 21,905 m3; 3m - 2.5-3.5m, 6,723 m3) summed and divided by the lake area (4.7 ha.), to obtain the mean density per m2. Colony size estimates were multiplied by their strata volume, summed and divided by the t o t a l lake volume (80,661 m 3), to obtain an estimate of the mean colony size for the entire lake. The o r i g i n a l results ( l e f t panels) are compared to the weighted results (right panels) in Graphs A to P that follow. Generally, the weighted estimates are lower than the o r i g i n a l r esults because of the lower contribution of estimates at two and three metres to the combined or averaged estimates for the entire lake. However, the effects of weighting the data on the Dinobryon colony size and density estimates are minimal and do not a l t e r the patterns of temporal change. The weighting e f f e c t s are more pronounced in the zooplankton density estimates, but again, temporal patterns of change are not al t e r e d . The results of weighting the data for strata volume emphasize three important points. F i r s t , the o r i g i n a l results, as f i r s t analyzed, hold. Second, the inferences and the hypothesis drawn from the o r i g i n a l analysis were s u f f i c i e n t l y robust to accomodate the a l t e r i n g of the results by the weighting procedure. Third, because the weighting of the data emphasizes the upper portions of the lake, the results of this thesis can be considered to be representative of t h i s region of the lake and, by extension, to most of the vernal Dinobryon populations that concentrate there. 1 73 The following graphs are organized as follows; A - Original Dinobryon colony size estimates (#LPC) D. cylindricum ( ) D. divergens ( — ) B - Weighted Dinobryon colony size estimates (#LPC) D. cylindricum ( ) D. divergens ( ) C - Original Dinobryon colony density estimates (#/m2 D. cylindricum ( ) D. divergens ( ) D - Weighted Dinobryon colony density estimates (#/m2 D. cylindricum ( ----) rj. divergens ( ) E - Original Diacyclops thomasi density estimates (#/m2) X100; Station I. F - Weighted Diacyclops thomasi density estimates (#/m2) X100; Station I. G - Original Diacyclops thomasi density estimates (#/m2) X100; Station I I . H - Weighted Diacyclops thomasi density estimates (#/m2) X100; Station I I. I - Original Daphnia longispina density estimates (#/m2) X100; Station I. J - Weighted Daphnia longispina density estimates (#/m2) X100; Station I. K - Origi n a l Daphnia longi spina density estimates (#/m2) X100; Station I I. L - Weighted Daphnia longispina density estimates (#/m2) X100; Station I I . M - Origi n a l Bosmina coregoni density estimates (#/m2) -X100; Station I. 1 74 N - Weighted Bosmina X1 00; Station I. coregon i density est imates U/m2) 0 - Original Bosmina X100; Station II . coregon i density est imates U/m2) P - Weighted Bosmina coregon i density estimates U/m2) X100; Station II. 175 1 7 6 CM 300 260 240 Z 180 — * HO 100-60-20" i r i r 300-260-2A0-(M ** 180-uo-100-60-20-i r mar apr 1 7 7 (M CM 300-] 260-240-180-* 140-100-60-20-300-1 260-240 2 180 * HO 100 60 20H i r i i i K Ln i I I I r mar apr 178 CM 300 2601 240 2 180 * uo-100 60" 20" M •O 0* fO CD T T i i r N I I I I I I CM 300" 260" 240" 2 180-*t 140 100 601 20 m to o cp m «-> — g> ro *r «*> I I I I I I mar apr n _ r i i I i r mar apr 

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