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Water quality in the lower Fraser River Basin : a method to estimate the effect of pollution on the size.. 1976

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WATER QUALITY IN THE LOWER FRASER RIVER BASIN: A METHOD TO ESTIMATE THE EFFECT OF POLLUTION ON THE SIZE OF A SALMON RUN by GUNTER HERBERT BROX D i p l . I n g . , U n i v e r s i t y o f K a r l s r u h e , W-Germany, 1973 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE i n THE FACULTY OF GRADUATE STUDIES The Department o f C i v i l E n g i n e e r i n g We a c c e p t t h i s t h e s i s as c o n f o r m i n g t o the r e q u i r e d s t a n d a r d THE UNIVERSITY OF BRITISH COLUMBIA June, 1976 (c) Gunter Herbert Brox, 1976 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f t h e r e q u i r e m e n t s f o r an a d v a n c e d d e g r e e a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e a n d s t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by t h e H e a d o f my D e p a r t m e n t o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . D e p a r t m e n t o f C i v i l E n g i n e e r i n g The U n i v e r s i t y o f B r i t i s h C o l u m b i a 2075 Wesbrook P l a c e V a n c o u v e r , C a n a d a V6T 1W5 D a t e June 10, 1976 i i ABSTRACT Water q u a l i t y s t u d i e s conducted i n the recent past i n the Lower Fra s e r R i v e r Basin i n d i c a t e d that l o c a l l y some high p o l l u t i o n l e v e l s e x i s t . With f u r t h e r u r b a n i z a t i o n and i n d u s t r i a l i z a t i o n of the Vancouver r e g i o n an increase i n waste loadings and a degradation of water q u a l i t y can be ex- pected i f no s t r i c t p o l l u t i o n c o n t r o l i s a p p l i e d . Of p a r t i c u l a r concern are b i o l o g i c a l l y undegradable substances such as heavy metals and p o l y - c h l o r i n a t e d hydrocarbons. They accumulate i n the sediments of the r i v e r and the estuary and become concentrated i n organisms of the food chain. P o l l u t i o n i s a g r a d u a l l y o c c u r r i n g process. A n t i c i p a t i o n of p o t e n t i a l problems i s important f o r the d e c i s i o n maker r e s p o n s i b l e f o r water q u a l i t y management. The Fraser R i v e r supports one of the l a r g e s t salmon runs of the world and i s abundant w i t h other commercially and r e c r e a t i o n a l l y v a l u a b l e f i s h . Salmon are very s e n s i t i v e t o p o l l u t i o n and could disappear from the Fraser r i v e r system as they a l r e a d y have from many other major r i v e r s i f p o l l u t i o n l e v e l s become too high. The Fraser R i v e r estuary has the f u n c t i o n of a b o t t l e n e c k . A d u l t salmon enter the r i v e r to migrate upstream to t h e i r spawning grounds, and j u v e n i l e salmon stay i n the estuary f o r a w h i l e to a c c l i m a t i z e themselves to the s a l i n e environment. I n t h i s t h e s i s a method i s presented to simulate the e f f e c t s of p o t e n t i a l p o l l u t i o n on the s i z e of a salmon stock. A model which uses data from various l i f e stages of a p a r t i c u l a r sockeye salmon run i n the F r a s e r system i s developed. U n c e r t a i n t i e s due to environmental f l u c t u a - t i o n s are accounted f o r . Using t h i s model the e f f e c t s of an increase i n m o r t a l i t y r a t e i n two stages of the sockeye salmon l i f e c y c l e on a d u l t r e t u r n numbers are studie d . The a n a l y s i s showed that at a c e r t a i n m o r t a l i t y r a t e chances are that the stock might not be able to recover. In l i g h t of a planned salmon enhancement program to increase salmon stocks i n various P a c i f i c r i v e r s , the f a c t that decreasing water q u a l i t y could counteract a l l enhancement e f f o r t s should be a warning s i g n a l to the d e c i s i o n makers. The development of a water q u a l i t y index to p r e d i c t f u t u r e condi- t i o n s i s recommended and a p o s s i b l e procedure to r e l a t e water q u a l i t y parameters to an increase i n m o r t a l i t y r a t e i s sketched out. iv TABLE OF CONTENTS Page ABSTRACT i i TABLE OF CONTENTS iv LIST OF TABLES v i i LIST OF FIGURES v i i i ACKNOWLEDGMENTS x CHAPTER I INTRODUCTION 1 II THE LOWER FRASER RIVER AND ITS WATER USERS . . . . 6 A. Description of the Lower Fraser River . . . . 6 B. Water Quality: A Review . 8 C. The Fraser River and its Water Users 14 D. The Salmon Resource 20 III LIFE CYCLE OF THE SOCKEYE SALMON 23 A. Introductions 23 B. The Chilko River Sockeye 24 1. Relationship Between Escapement and Female S pawners . 27 2. Relationship Between Female Spawners and Deposited Eggs 29 3. Relationship Between the Number of Deposited Eggs and the Number of Fry 29 4. Relationship Between the Number of Fry and the Number of Smolt 31 5. Relationship Between the Number of Smolts and the Number of Returning Adults 33 V CHAPTER Page IV A MODEL USING DATA RECORDS WHERE AVAILABLE AND JUDGMENT OF EXPERTS 38 A. Introduction 38 B. Uncertainty and Expected Return 40 C. Choice of a Distribution Function 42 D. Development of the Probability Matrices . . . . 43 E. Conclusions 45 V THE POLLUTION EFFECTS ON SALMON - HOW MUCH DO WE KNOW? -- A REVIEW 48 A. Introduction 48 B. C r i t i c a l Pollutants in the Salmon Food Chain . . 49 C. Experimental Evidence 52 : VI SIMULATION OF A SALMON STOCK UNDER VARIED LEVELS OF POLLUTION 58 A. Introduction 58 B. Fish Tests in the Fraser River and the Coastal Zone 59 C. Effects of Various Mortality Rates on the Size of a Sockeye Salmon Stock 61 VII THE USEFULNESS OF AN INDEX TO FORECAST WATER QUALITY CHANGES AND THEIR EFFECTS ON WATER USE 73 A. Pro and Contra for Developing a Water Quality Index 73 B. Construction of a Water Quality Index for Fish and Wildlife 74 C. Forecasting Potential Pollution Effects . . . . 77 CHAPTER Page V I I I DISCUSSION AND CONCLUSIONS 86 BIBLIOGRAPHY 91 APPENDIX 1 LOGNORMAL VERSUS NORMAL DISTRIBUTION 96 2 FLOW CHART OF THE MODEL 100 v i i LIST OF TABLES Page TABLE 1 FACTORS INFLUENCING THE TOXICITY OF HEAVY METALS TO AQUATIC ORGANISMS 50 2 PARAMETERS AND THEIR IMPORTANCE WEIGHTS FOR CONSTRUCTION OF A WATER QUALITY INDEX FOR FISH AND WILDLIFE 77 v i i i LIST OF FIGURES FIGURE Page 1 LOWER FRASER RIVER 7 2 OFFICIAL REGIONAL PLAN 16 3 DISTRIBUTION OF SOCKEYE SALMON SPAWNING GROUNDS IN THE FRASER RIVER WATERSHED . . . . . . . . . . . 25 4 CHLLKO LAKE, CHILKO RIVER, AND SPAWNING GROUNDS OF SOCKEYE SALMON 26 5 RELATIONSHIP BETWEEN ESCAPEMENT AT THE MOUTH OF THE RIVER AND FEMALE SPAWNERS REACHING SPAWNING GROUNDS . ... 28 6 FEMALE SPAWNERS VS EGGS DEPOSITED 30 7 EGGS DEPOSITED VS FRY PRODUCED 32 8 FRY VS SMOLTS ° 34 9 SMOLTS MIGRATING TO THE OCEAN VS RETURNING ADULT SALMON 36 10 EXPECTED RETURN (MORTALITY RATE 0%) 46 11 A POSSIBLE RELATION BETWEEN PHYSIOLOGICAL IMPAIRMENT FOLLOWING INCREASING EXPOSURE TO POLLUTANTS AND THE CONSEQUENT DISABILITY OF THE FISH (AFTER HATCH) . . . 55 12 EXPECTED RETURN (MORTALITY RATE 57») 63 13 EXPECTED RETURN (MORTALITY RATE 107.) 64 14 EXPECTED RETURN (MORTALITY RATE 207o) . . . . . . 65 15 EXPECTED RETURN (MORTALITY RATE 307,) 66 16 EXPECTED RETURN (MORTALITY RATE 407o) 67 .17 EXPECTED RETURN (MORTALITY RATE 50%) 68 18 POSSIBLE MANAGEMENT SCHEME TO HARVEST SALMON . . . . 70 19 SUSTAINABLE RUN WITH ESCAPEMENT STRATEGY OF FIG. 18 (EQUILIBRIUM LEVEL) 71 20 WATER QUALITY AS A FUNCTION OF D.O. SATURATION, SUMMER TEMPERATURES 78 i x FIGURE Page 21 WATER QUALITY AS A FUNCTION OF TEMPERATURE DEPARTURE FROM AMBIENT 78 22 WATER QUALITY AS A FUNCTION OF pH 79 23 WATER QUALITY AS A FUNCTION OF PHENOL CONCENTRATION . . 79 24 WATER QUALITY AS A FUNCTION OF TURBIDITY 80 25 WATER QUALITY AS A FUNCTION OF DISSOLVED SOLIDS CONCENTRATION 80 26 WATER QUALITY AS A FUNCTION OF AMMONIA CONCENTRATION . 81 27 WATER QUALITY AS A FUNCTION OF NITRATE CONCENTRATION . 81 28 WATER QUALITY AS A FUNCTION OF PHOSPHATE CONCENTRATION . 82 29 POSSIBLE RELATIONSHIPS BETWEEN A WATER QUALITY INDEX AND MORTALITY RATE (SOCKEYE SALMON) 84 30 WATER QUALITY INDEX OVER TIME 84 APPENDIX IA NORMAL PROBABILITY DISTRIBUTION 99 2A LOGNORMAL PROBABILITY DISTRIBUTIONS FOR DIFFERENT STANDARD DEVIATION VALUES 99 X ACKNOWLEDGMENTS This t h e s i s has been prepared i n p a r t i a l f u l f i l l m e n t of the r e - quirements f o r the degree of a Master of A p p l i e d Science. In t h i s study use was made of a v a i l a b l e i n f o r m a t i o n from experts i n d i f f e r e n t s c i e n t i f i c f i e l d s . They devoted much of t h e i r v a l u a b l e time p r o v i d i n g i n f o r m a t i o n and c r i t i c i s m . Thanks are owed to Dr. J e f f Thompson from the P a c i f i c Environment I n s t i t u t e , West Vancouver; Otto Langer from the F i s h e r i e s and Marine S e r v i c e , Environment Canada; Dr. M. Takahashi, p r e s e n t l y w i t h the CEPEX research group i n Saanich I n l e t , Vancouver I s l a n d ; Dr. C a r l Walters from the I n s t i t u t e of Animal Resource Ecology at the U n i v e r s i t y of B r i t i s h Columbia; Dr. Ken H a l l , Anthony Dorcey, and Fred Koch from the Westwater Research Centre at U.B.C, and many others. A great debt i s owed to Dr. Jim Woodey from the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission, New Westminster who provided some of the i n f o r m a t i o n used f o r the model and donated much of h i s time i n d i s c u s s i n g the r e s u l t s and making h e l p f u l suggestions. F i n a l l y , I owe a great debt of g r a t i t u d e to P r o f e s s o r S.O. Russel f o r guiding me and having time whenever I needed advice or encourage- ment. S p e c i a l acknowledgment i s made to Mr. Richard Brun of the Department of C i v i l Engineering who d i d the d r a f t i n g of a l l the f i g u r e s presented i n t h i s t h e s i s . 1 CHAPTER I INTRODUCTION "The Greater Vancouver Region reached a population of 1,140,000 people i n 1974. I t i s c u r r e n t l y growing at a r a t e s l i g h t l y under 37» a year. Even at a lower r a t e of growth the p o p u l a t i o n w i l l reach n e a r l y 1,500,000 by 1986, and approach 2,000,000 by the year 2000." This s t a t e - ment, made i n the L i v e a b l e Region Plan (63) i l l u s t r a t e s the r a p i d growth of u r b a n i z a t i o n i n an area which i s a l s o considered as one of the most productive e c o l o g i c a l systems on the North American continent: The Fraser R i v e r Estuary. There has not been only a r a p i d r i s e i n population, but a l s o demand of more products which leads to increased production and increased waste generation by bothr producer and consumer. This c o n c e n t r a t i o n of people and i n d u s t r i e s i n a l o c a l i z e d area burdens the environment w i t h very h i g h waste loadings. Therefore, environmental management has to be a key f a c t o r i n keeping the n a t u r a l environment of Vancouver i n the s t a t e that has been enjoyed by i t s r e s i d e n t s f o r many years and made Vancouver a major t o u r i s t centre on the west coast. Environmental d e t e r i o r a t i o n could a l s o be economically damaging i f i t s t i f l e s development of some major s e r v i c e i n d u s t r i e s or research i n s t i t u t i o n s (64). Unfortunately, e s t u a r i e s have o f t e n been regarded by modern man as useless because of t h e i r swampy±lands. Therefore, he dyked them, land- f i l l e d them, and o f t e n developed i n d u s t r i a l parks i n these areas. This has happened i n many e s t u a r i e s a l l over the world. The f a c t s , however, show that e s t u a r i e s and the nearshore c o a s t a l lands are the b i o l o g i c a l l y 2 most productive areas of the marine ecosystem. There are great n a t u r a l v a r i a t i o n s i n the f l o r a and fauna of these areas. Resident organisms can t o l e r a t e and compensate f o r the v a r i a b l e c o n d i t i o n s that r e s u l t from the t i d a l movements. For t h i s reason the c a p a c i t y of e s t u a r i e s to accept p o l l u t a n t s which enhance n a t u r a l v a r i a t i o n s i s r e l a t i v e l y great. However, there are l i m i t s to t h i s environmental acceptance. We have to consider these i n each case of development i f we want to maintain the high n a t u r a l p r o d u c t i v i t y of the estuary. There have been warnings from various sides regarding the impact of proposed development i n the estuary on f i s h and w i l d l i f e (16, I n t . Pac. Salmon F i s h . Comm. Annual Report 1974). Each development reduces the area covered by mudflats and t i d a l marshland. The value of these marshlands i s o f t e n underestimated. Many species><rdf f i s h are dependent on the estuary f o r some part of t h e i r l i v e s . S h e l l f i s h such as oyster, crab, and shrimp, depend on the c o a s t a l e s t u a r i e s as w e l l . Furthermore, the mudflats and the t i d a l marshland serve as a r e s t i n g place f o r many shorebirds,, waterfowl, ... and other w i l d l i f e . Thus, i n f u n c t i o n , t h i s h a b i t a t cannot be replaced e a s i l y by some other land. Westwater, an i n t e r d i s c i p l i n a r y research group at the U n i v e r s i t y of B r i t i s h Columbia has conducted a study during the past three years to define the p o l l u t i o n problem i n the Lower Fraser R i v e r , to b r i n g i t to the a t t e n t i o n of the p u b l i c , and to develop a p o l i c y to manage t h i s impor- tant water system. In t h e i r conclusions they found that there are "clouds on the horiz o n " . There i s great u n c e r t a i n t y about some p o t e n t i a l l y harm- f u l substances which have been encountered i n the water, the bottom s e d i - ments, or the t i s s u e of f i s h . Often the sources of these p o l l u t a n t s are not known; one can only estimate very cr u d e l y the q u a n t i t i e s that are p r e s e n t l y discharged to the r i v e r ; only p a r t i a l knowledge of t h e i r path- ways through the aquatic system e x i s t s . Studies to determine t h e i r accumu- l a t i o n rates i n the food chain have j u s t been s t a r t e d (14,30)• There i s great need f o r research i n t o the processes and pathways of p o l l u t a n t s w i t h i n the Fraser R i v e r system and f o r the study of the e f f e c t s that c e r t a i n p o l l u t a n t s can have on b i o l o g i c a l communities i n r e l a t i o n to c o n c e n t r a t i o n and time of exposure. Most of the studies that have been undertaken involved sampling programs. There e x i s t s a lack of h i s t o r i c a l data f o r most water q u a l i t y parameters. Almost nothing was known about the chemical composition of the bottom sediments, the concen- t r a t i o n of t r a c e elements i n the t i s s u e of some organisms, and the v a r i e t y and number of species that i n h a b i t the r i v e r system. H i s t o r i c a l data are very important i n order to decide whether measured concentrations r e f l e c t mainly n a t u r a l background l e v e l s or man-made p o l l u t i o n . Water q u a l i t y i s u s u a l l y described by p h y s i c a l and chemical parameters. The measured values are then r e l a t e d to the e f f e c t s that they may have on man or aquatic organisms. At present we are mainly concerned to evaluate the e x i s t i n g water q u a l i t y c o n d i t i o n s . As the region of Greater Vancouver grows i n p o p u l a t i o n and w i t h i t the economic a c t i v i t i e s increase, we have to expect higher waste loadings. We have to decide upon p o l i c i e s and abatement technologies to cope w i t h the water p o l l u t i o n problem now i f we want to prevent any d e t e r i o r a t i o n of the water q u a l i t y w i t h i n the next 10 or 20 years. P r e v e n t i v e planning i s b e t t e r than passive adaptation. I f we s t a r t c o r r e c t i n g u n d e s i r a b l e water q u a l i t y c o n d i t i o n s at a time when everybody can smell or see or q u a n t i f y the p o l l u t i o n problem, costs w i l l be much higher than i f we s t r e t c h an abatement program over a number of years, or begin time consuming research 4 now. We have to decide now: - whether to go f o r more dredging i n the mouth of the r i v e r and thus destroy the marshland; - whether to b u i l d more dykes which create areas of stagnating water i n which s e v e r a l water q u a l i t y parameters such as temperature, s a l i n i t y , pH, ion c o n c e n t r a t i o n may change to an extent that t h i s water can no longer support aquatic l i f e ; - whether to t r e a t stormwater r u n o f f that c a r r i e s s t r e e t contaminants and washed-out p o l l u t a n t s from the a i r ; whether to c o l l e c t and t r e a t leachate from l a n d f i l l s as they o f t e n c o n t a i n very high concentrations of substances that are t o x i c to aquatic organisms; - whether to reduce i n c r e a s i n g concentrations of f e r t i l i z e r s and p e s t i - cides i n a g r i c u l t u r a l r u n o f f before i t reaches the r i v e r . A l l these problems are f a c i n g the d e c i s i o n makers who are involved i n management and development of the Lower Fraser R i v e r basin. One way to a n t i c i p a t e p o t e n t i a l p o l l u t i o n and to estimate i t s e f f e c t s i s described i n t h i s t h e s i s . As background Chapter I I i l l u s t r a t e s present water q u a l i t y c o n d i t i o n s and discusses the various users of Fraser R i v e r water. For t h i s t h e s i s salmon were chosen as an example to i l l u s - t r a t e how f u t u r e p o l l u t i o n could c u r t a i l b i o l o g i c a l p r o d u c t i v i t y of the estuary. Salmon r e q u i r e water of h i g h q u a l i t y , f r e e of harmful p o l l u t a n t s throughout the watershed. This v a l u a b l e and most s e n s i t i v e species of f i s h has disappeared from many European and North American r i v e r s due to h i g h p o l l u t i o n l e v e l s . Chapter I I I describes how information about a major salmon run i n the Fraser R i v e r system can be brought i n t o a form that 5 , allows d e s c r i p t i o n of u n c e r t a i n t y i n terms of p r o b a b i l i t i e s . This informa- t i o n i s used as input data i n a model which c a l c u l a t e s expected r e t u r n values of adu l t salmon. I n Chapter IV the mathematical d e t a i l s of t h i s model are presented. Chapter V gives a review of research on the e f f e c t s that various p o l l u t a n t s have on salmon. In Chapter VI some of the studies on acute t o x i c i t y and s u b l e t h a l e f f e c t s conducted i n the Lower Fraser R i v e r and the c o a s t a l waters are reviewed. I t a l s o presents the r e s u l t s of computer sim u l a t i o n s that have been done to estimate f u t u r e salmon r e t u r n f i g u r e s when the stock i s subjected to various assumed m o r t a l i t y r a t e s . This increase i n m o r t a l i t y may r e s u l t as the salmon has to pass through i n c r e a s i n g l y p o l l u t e d waters of the Fraser estuary as t h i s area continues to be developed i n the f u t u r e . In Chapter V I I the c o n s t r u c t i o n of a water q u a l i t y index f o r salmon as a major water user i s proposed. Such a water q u a l i t y index could be used to p r o j e c t the e f f e c t s of fu t u r e development i n the r i v e r b asin r a t h e r than f o r e c a s t i n g loadings of each s i n g l e p o l l u - tant. P o s s i b l e r e l a t i o n s h i p s between such a water q u a l i t y index and an increase i n m o r t a l i t y r a t e are suggested. Chapter V I I I contains a d i s - c u s s i o n and summarizes the conclusions. 6 CHAPTER I I THE LOWER FRASER RIVER AND ITS WATER USERS A. D e s c r i p t i o n of the Lower Fraser R i v e r The Lower Fraser system extends about 8 5 miles from Hope to the S t r a i t of Georgia. I t comprises s e v e r a l t r i b u t a r i e s , s m a ll backwaters, s i d e channels, sloughs, and marshes. Figure 1 gives an overview of the system. At New Westminster, the Fraser branches i n t o the Main Arm (approxi- mately 9 0 7 o of the flow) and the North Arm (approximately 1 0 7 ° of the flow) . The North Arm b i f u r c a t e s a t Sea I s l a n d thus c r e a t i n g another arm which i s r e f e r r e d to as the Middle Arm. Flow i n the Fraser R i v e r and i t s l a r g e r , mountain t r i b u t a r i e s i s c h a r a c t e r i z e d by a wi n t e r minimum and a l a t e s p r i n g maximum as s o c i a t e d w i t h runoff from snow melt. The mean discharge a t Hope has been recorded as 9 4 , 6 0 0 c f s w i t h extremes of 5 3 6 , 0 0 0 c f s and 1 2 , 0 0 0 c f s ( 6 ) . Present uses and functions of the estuary are determined to a lar g e extent by the New Westminster-Vancouver m e t r o p o l i t a n area. The Greater Vancouver Region accommodates about 5 0 7 o of the p o p u l a t i o n of B r i t i s h Columbia. Doubling of i t s p o p u l a t i o n i s p r e d i c t e d f o r the t u r n o f the century ( 6 3 ) . Most of the new growth w i l l take place to the south and east of Vancouver. This w i l l place a heavy emphasis on the r i v e r w i t h regard to r e s i d e n t i a l , commercial, and i n d u s t r i a l development. I t can be expected that the Lower Fraser w i l l a t t r a c t more i n d u s t r i e s i n the fu t u r e because of i t s access to the open sea. More goods w i l l be processed along the w a t e r f r o n t , and harbour f a c i l i t i e s w i l l be expanded as Canada's f o r e i g n trade i n c r e a s i n g l y s h i f t s to the West FIGURE 1 LOWER FRASER RIVER Scot* < l"« Mil* * Approx. 1 I i ' O t K> IIIIUIIH 8 (48). A l l t h i s development w i l l have i m p l i c a t i o n s f o r water q u a l i t y . As t h e r e a r e many and sometimes c o n f l i c t i n g water uses i t i s i m p o r t a n t t h a t the impact o f every new development on water q u a l i t y be a s s e s s e d . F o r doi n g so a sound b a s i s o f dat a r e f l e c t i n g water q u a l i t y o f the n a t u r a l s t r e a m or a t l e a s t w i t h o n l y minor changes i s r e q u i r e d . I n the p a s t 20 y e a r s s e v e r a l s t u d i e s have been undertaken t o e s t a b l i s h t h i s data b a s i s . B. Water Q u a l i t y - Change o f the p o l l u t i o n p a t t e r n ? A r e v i e w o f r e c e n t water q u a l i t y i n v e s t i g a t i o n s . U n t i l the e s t a b l i s h m e n t o f the P o l l u t i o n C o n t r o l Board (PCB) and the G r e a t e r Vancouver Sewerage and D r a i n a g e D i s t r i c t (GVS & DD) i n 1956, p h y s i c a l , c h e m i c a l , and b a c t e r i o l o g i c a l d a t a were c o l l e c t e d by the P r o - v i n c i a l H e a l t h Branch. A r e p o r t p u b l i s h e d by the P o l l u t i o n C o n t r o l Board i n 1967 c o n c l u d e d t h a t the main stem o f the Lower F r a s e r was found t o be a " c l e a n stream" i n terms o f BOD c o n t e n t ; however, e x i s t i n g b a c t e r i o l o g i c a l l e v e l s were u n d e s i r a b l y h i g h ( 1 9 ) . Between 1963 and 1966 the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission (IPSFC) conducted a sur v e y o f water q u a l i t y and bottom organisms (54). The purpose o f t h i s s t u d y was m a i n l y t o p r o v i d e background i n f o r m a - t i o n on w a t e r q u a l i t y b e f o r e some p u l p m i l l s began o p e r a t i o n s on the Upper F r a s e r and Thompson r i v e r s . T h i s s t u d y was not a comprehensive s u r v e y o f a l l types o f p o s s i b l e p o l l u t a n t s . Samples taken were a n a l y s e d f o r t h e i r c o n t e n t o f o r g a n i c s (measured as BOD and COD), d i s s o l v e d oxygen, and s e v e r a l o t h e r parameters t h a t a r e r e l a t e d t o pu l p m i l l wastes. The c o m p o s i t i o n o f the p o p u l a t i o n o f b o t t o m - d w e l l i n g organisms, i n c l u d i n g m a c r o i n v e r t a b r a t e s and b a c t e r i a l s l i m e s was a l s o determined. T h i s s t u d y was f o l l o w e d by a more comprehensive one d u r i n g which samples were t a k e n i n the s p r i n g o f 1966, 1967, and 1968 a t some l a k e o u t l e t s , w hich s e r v e as n u r s e r y a r e a s f o r young salmon, and a t M i s s i o n on the F r a s e r R i v e r . These samples were a n a l y s e d f o r v a r i o u s substances c o n s i d e r e d as p o t e n t i a l l y t o x i c t o salmon- o i d s . The parameters i n c l u d e d heavy m e t a l s , c y a n i d e s , s u r f a c t a n t s , and c h l o r i n a t e d hydrocarbons ( p e s t i c i d e s and h e r b i c i d e s ) . No h a r m f u l concen- t r a t i o n s were d e t e c t e d . BOD was low w i t h 907„ o f t h e samples showing a c o n c e n t r a t i o n o f l e s s than 2 ppm and 3.1 ppm the h i g h e s t v a l u e . I t was found t h a t o r g a n i c l o a d , t u r b i d i t y and s o l i d s were g r e a t e r d u r i n g the s p r i n g f r e s h e t t h a n d u r i n g the r e s t o f the y e a r w h i c h i n d i c a t e s t h a t the s o u r c e s a r e m a i n l y n a t u r a l . H i g h e r l e v e l s o f p o l l u t i o n were en c o u n t e r e d i n t h e N o r t h Arm o f t h e r i v e r thus showing t h e e f f e c t s o f i n d u s t r i a l d e v e l - opment i n t h i s r e a c h . T h i s study emphasized t h a t s h i f t s o f the b i o l o g i c a l community can r e v e a l more than c h e m i c a l water a n a l y s e s . Changes i n p o l l u - t i o n a r e i n d i c a t e d by changes i n c o m p o s i t i o n o f the b i o l o g i c a l community as some o f the organisms a r e more s e n s i t i v e t o p o l l u t e d c o n d i t i o n s t h a n o t h e r s . A m o n i t o r i n g program by the F i s h e r i e s S e r v i c e , Department o f t h e Environment, c o n d u c t e d d u r i n g the summer-fall season o v e r a t h r e e y e a r p e r i o d from 1969-1971 was p r i m a r i l y concerned w i t h BOD and DO l e v e l s i n the Roberts Bank, S t u r g e o n Bank, l o n a Beach, E n g l i s h Bay, and F a l s e Creek a r e a s . DO l e v e l s were g e n e r a l l y g r e a t e r than 907, s a t u r a t i o n . O n l y a t some s t a t i o n s i n t h e N o r t h Arm were lower l e v e l s (777,-907, s a t u r a t i o n ) p e r i o d i c a l l y d e t e c t e d ( 6 ) . An o t h e r r e p o r t done by B.C. Research on water q u a l i t y i n t h e lower reaches below P o r t Mann B r i d g e d u r i n g the f a l l o f 1971 i s c o n t a i n e d i n t h e P r o v i n c i a l Power Study o f 1972 ( 4 ) . T h i s s u r v e y a l s o i n c l u d e d sediment s a m p l i n g , and p r o f i l e s a m p l i n g a t s e l e c t e d s t a t i o n s o v e r a t i d a l c y c l e . I n g e n e r a l , t h e d i s s o l v e d oxygen l e v e l s were found t o be near s a t u r a t i o n , 10 except f o r bottom samples and samples from i s o l a t e d , c h a n n e l s where some low d i s s o l v e d oxygen l e v e l s were o b t a i n e d . T h i s can be e x p e c t e d as sl o u g h s and backwaters a r e more s e n s i t i v e t o r a i s e d p o l l u t i o n l e v e l s . These s h a l l o w water b o d i e s warm up more r a p i d l y , the p r o c e s s o f b i o d e g r a d a t i o n i s a c c e l - e r a t e d and t h e r e f o r e more oxygen i s consumed. P o l l u t a n t s a r e o f t e n not f l u s h e d out o f the system because t h e r e i s h a r d l y any water movement. In t h i s s t u d y some b i o l o g i c a l l y s i g n i f i c a n t c o n c e n t r a t i o n s o f copper, z i n c , and l e a d i n some samples were r e p o r t e d ; however, most a n a l y s e s showed con- c e n t r a t i o n s lower than those c o n s i d e r e d d e t r i m e n t a l t o f i s h l i f e . As p a r t o f i t s Lower F r a s e r R i v e r s t u d y Westwater R e s e a r c h C e n t r e conducted two major water sampling programs. I n a p r e l i m i n a r y s u r v e y (6) d u r i n g t h e months o f J u l y and August, 1972, when flows were h i g h , samples were taken a t 22 s t a t i o n s on the F r a s e r between Hope and t h e mouth o f t h e r i v e r , and a t 24 t r i b u t a r y s t a t i o n s . T h i s s t u d y r e v e a l e d t h a t f i v e t r i b u - t a r i e s , C h i l l i w a c k Creek, Salmon R i v e r , Sumas R i v e r , B r u n e t t e R i v e r , and Nicomen Slough, showed a lower water q u a l i t y t h a n the Lower F r a s e r R i v e r i t s e l f . C o nsequently, l a t e r s t u d i e s were conducted on these s m a l l t r i b u t a r y b a s i n s . I t a l s o showed t h a t p o t e n t i a l l y t o x i c m a t e r i a l s such as heavy m e t a l s , PCB's ( p o l y c h l o r i n a t e d b i p h e n y l s ) , o r DDT and i t s d e g r a d a t i o n p r o - ducts a r e more l i k e l y t o appear i n the sediment and t i s s u e o f a q u a t i c organisms t h a n i n t h e water i t s e l f , because o f t h e i r r e l a t i v e i n s o l u b i l i t y . The second water q u a l i t y s t u d y (22) was based on t h e s e f i n d i n g s . D u r i n g F e b r u a r y through May, 1973, when flows were low, samples were taken weekly from 9 s t a t i o n s i n t h e Lower F r a s e r and 15 s t a t i o n s i n s e l e c t e d t r i b u t a r i e s . An a d d i t i o n a l 70 samples were t a k e n t o be a n a l y s e d f o r p e s t i - c i d e s . The r e s u l t s o f t h e s e two programs showed t h a t w ater q u a l i t y was remarkably good i n the F r a s e r R i v e r . D i s s o l v e d oxygen l e v e l s i n t h e Main 11 Arm were c l o s e to s a t u r a t i o n and s l i g h t l y lower i n the North Arm. Present BOD loadings and p r o j e c t e d waste discharges are not expected to a f f e c t these h i g h d i s s o l v e d oxygen l e v e l s d r a s t i c a l l y . This r e s u l t was observed from a study where a mathematical model was used to simulate d i s p e r s i o n and degradation of organic wastes (27). However, some depressed oxygen l e v e l s were encountered i n s e v e r a l of the small t r i b u t a r i e s where flows are not s u f f i c i e n t to d i l u t e the wastes discharged to the r i v e r . A major water q u a l i t y problem appears to e x i s t i n the high l e v e l s of i n d i c a t o r micro- organisms i n the Fraser and some t r i b u t a r i e s . I t was found that the bac- t e r i o l o g i c a l q u a l i t y of the water g r a d u a l l y d e t e r i o r a t e d from Hope to the S t r a i t of Georgia. These high numbers of i n d i c a t o r microorganisms appear mainly to r e s u l t from discharge of untreated domestic sewage. A f t e r com- p l e t i o n of the Annacis I s l a n d treatment pl a n t the b a c t e r i o l o g i c a l s i t u a t i o n i s expected to improve. Concentrations of some heavy metals were occasion- a l l y h i g h but none reached l e v e l s that are considered a c u t e l y t o x i c to f i s h . Since i n t h i s study only grab samples were taken once a week, these r e s u l t s have to be i n t e r p r e t e d w i t h some ca u t i o n . As metal discharges by some i n d u s t r i e s are u s u a l l y sporadic i n nature a p o t e n t i a l l y short-term t o x i c s i t u a t i o n , c l o s e to the o u t f a l l , might a r i s e . A l s o , i n periods of low flow, a body of water i n the lower reaches of the r i v e r may move up and down the r i v e r through s e v e r a l t i d a l c y c l e s before reaching the sea, g i v i n g r i s e to the accumulation of p o l l u t a n t s . Metal concentrations i n a h i g h l y sediment-loaded r i v e r are u s u a l l y not very high as the metals become adsorbed to the p a r t i c u l a t e m a t e r i a l and sink to the r i v e r bottom. S e d i - ment samples are t h e r e f o r e much more i n d i c a t i v e of t r a c e metal contamina- t i o n . However, i t i s d i f f i c u l t to decide which f r a c t i o n of metal i s 12 a t t r i b u t a b l e t o l e a c h i n g o f m i n e r a l d e p o s i t s i n t h e mountain ranges and s o i l s i n the a l l u v i a l p l a i n o f the F r a s e r V a l l e y and which f r a c t i o n i s a t t r i b u t a b l e t o u r b a n - i n d u s t r i a l s o u r c e s . Most o f the h i g h e r m e t a l con- c e n t r a t i o n s i n the water and the sediment were e n c o u n t e r e d i n the B r u n e t t e R i v e r B a s i n w h i c h d r a i n s an u r b a n - i n d u s t r i a l a r e a (23,24). P a r t i c u l a r l y copper and l e a d showed f a i r l y h i g h and s t r o n g l y f l u c t u a t i n g c o n c e n t r a t i o n l e v e l s . A l s o z i n c c o n c e n t r a t i o n s were o f t e n above n a t u r a l background l e v e l . M ercury c o n c e n t r a t i o n s i n the water found between the P o r t Mann B r i d g e and the S t r a i t o f G e o r g i a were h i g h e r than i n the t r i b u t a r y system and can t h e r e f o r e n o t be e x p l a i n e d as background l e v e l s . The a n a l y s e s f o r p e s t i - c i d e s i n the water were a l l l e s s than d e t e c t i o n l i m i t s e x c e p t f o r one sample. As p e s t i c i d e s a r e v e r y i n s o l u b l e i n water and become adsorbed t o p a r t i c u l a t e m a t e r i a l v e r y r a p i d l y , i t was d e c i d e d t o t a k e sediment samples. Between F e b r u a r y and August, 1974 samples from t h e B r u n e t t e , Salmon, and Sumas r i v e r s were a n a l y s e d f o r p e s t i c i d e r e s i d u e s by the Water Q u a l i t y Branch o f Environment Canada. The most c o n t a m i n a t e d r i v e r b a s i n was the B r u n e t t e b a s i n . Samples from i t s r i v e r sediments c o n t a i n e d DDT, i t s d e g r a d a t i o n p r o d u c t s , and p o l y c h l o r i n a t e d b i p h e n y l s (PCB's), the l a s t ones b e i n g the most prominent contaminants i n t h i s u r b a n i n d u s t r i a l d r a i n a g e b a s i n (23). To d e t e r m i n e the impact of l a n d use upon sediment q u a l i t y , s t r e e t s u r f a c e m a t e r i a l s were c o l l e c t e d from f o u r d i f f e r e n t l a n d use areas and a n a l y z e d . The same c h l o r i n a t e d h y d rocarbons were found i n s t r e e t s u r - f a c e samples as o c c u r r e d i n stream sediments. T r a c e metal c o n c e n t r a t i o n s found i n the sediments were p a r t i c u l a r l y h i g h near sewage o u t f a l l s . A major d i s c h a r g e r i n t h i s r e g a r d i s t h e Iona Sewage Treatment p l a n t . A s t u d y done by B.C. R e s e a r c h i n 1973 (5) r e p o r t e d 13 t h a t c o n c e n t r a t i o n l e v e l s o f some metals exceeded q u i t e s i g n i f i c a n t l y background l e v e l s measured some d i s t a n c e from the co n t a m i n a t e d m u d f l a t s . There was a 1 - 6 - f o l d i n c r e a s e over background f o r c o b a l t , n i c k e l , and i r o n , and a 2 1 - f o l d i n c r e a s e f o r l e a d . Chromium, copper, and z i n c a l s o showed h i g h e r l e v e l s . These c o n c e n t r a t i o n s s h o u l d be o f some c o n c e r n as the p o s s i b i l i t y e x i s t s t h a t these substances accumulate i n c r a b s , s h e l l f i s h , f i s h , and w a t e r f o w l , thus c o n t a m i n a t i n g food f o r human consumption. A surv e y o f the b e n t h i c a n i m a l community o f the F r a s e r R i v e r m u d f l a t s d u r i n g t h e summer o f 1972 r e v e a l e d t h a t c o n c e n t r a t i o n s o f mercury, s i l v e r , and copper i n some ani m a l s from S t u r g e o n Bank were h i g h e r than samples from the a d j a c e n t R o b e r t s Bank (47). A n a l y s e s o f the muscle t i s s u e o f 348 specimens r e p r e s e n t i n g 14 s p e c i e s o f r e s i d e n t and m i g r a t o r y f i s h o f the F r a s e r R i v e r showed c o n c e n t r a - t i o n s o f mercury, copper, z i n c , i r o n , and manganese i n v i r t u a l l y a l l f i s h (44). As f i s h move around, i t i s h a r d l y p o s s i b l e t o t r a c e the accumulated t r a c e metals back t o t h e i r s o u r c e s . Of most c o n c e r n were the h i g h l e v e l s of mercury found i n two r e s i d e n t f i s h s p e c i e s , S quawfish and P r i c k l y S c u l p i n , w i t h c o n c e n t r a t i o n s r a n g i n g above the a c c e p t e d l e v e l i n C a n a d i a n food. These two f i s h s p e c i e s a r e not themselves food f i s h f o r man. The so u r c e o f t h i s c o n t a m i n a t i o n was not obv i o u s . T r a c e m e t a l c o n c e n t r a t i o n l e v e l s i n salmon, a m i g r a t o r y f i s h , were v e r y low. In comparison t o o t h e r r i v e r s i n N o r t h America and Europe t h e Lower F r a s e r R i v e r appears t o be c l e a n w i t h r e g a r d t o most t o x i c m a t e r i a l s , but t h e r e i s a p o t e n t i a l f o r i n c r e a s e s as i s i n d i c a t e d by the r e s u l t s from some t r i b u t a r y r i v e r s w hich d r a i n the m e t r o p o l i t a n a r e a o f Vancouver. In the main c h a n n e l no problems s h o u l d be met i n the f u t u r e as f a r as d i s s o l v e d oxygen, BOD, o r n u t r i e n t c o n c e n t r a t i o n s a r e concerned. However, we can 14 expect l o c a l i z e d s i t u a t i o n s of oxygen d e p l e t i o n , n u t r i e n t enrichment, h i g h b a c t e r i a l l e v e l s , t r a c e metals, and c h l o r i n a t e d hydrocarbons i n some t r i b u - t a r i e s , backwaters, and sloughs. C. The Fraser R i v e r and i t s Water Users In an area l i k e the Lower Fraser R i v e r b a s i n a m u l t i t u d e of a c t i v i - t i e s place demands on the water resource. I t i s important to recognize the impact that each of them has on water q u a l i t y i n order to prevent or m i n i - mize c o n f l i c t s between the d i f f e r e n t users. The Lower Fraser has h i s t o r i c a l l y been an important waterway f o r the transport of l o g booms from the u p r i v e r areas to the sawmills l o c a t e d on the estuary. A l s o , the estuary has always served as a l o g storage area, a use which can sometimes c o n f l i c t w i t h c e r t a i n r e c r e a t i o n a l demands such as boating and s p o r t s f i s h i n g . The r i v e r i s used by l o g r a f t s , barges, and deep sea v e s s e l s and provides docking f a c i l i t i e s along i t s banks. The s h a l l o w - d r a f t North Arm w i l l l i k e l y continue to serve as a waterway f o r the various f i s h processing and woodproduct i n d u s t r i e s which are l o c a t e d along i t s w a t e r f r o n t . The harbour i n the main stem of the Fraser R i v e r i s p r e s e n t l y Western Canada's second most important deep sea p o r t . I t has become the focus of considerable i n d u s t r i a l i n t e r e s t because there are s t i l l e xtensive areas of land vacant along the w a t e r f r o n t . At present dock f a c i l i t i e s f o r a new container t e r m i n a l are under c o n s t r u c t i o n . I n order to reduce the amount of dredging necessary to keep the channel at a depth of 33 f t , plans are being considered to construct t r a i n i n g w a l l s to con- t r a c t the c r o s s e c t i o n and thus increase the v e l o c i t y which would make the r i v e r s e l f - s c o u r i n g . U n f o r t u n a t e l y t h i s measure would cut o f f many f i s h species from the r e a r i n g and feeding areas i n the backwaters and sloughs of 15 the e s t u a r y . Of the 133 m i l e s o f harbour w a t e r f r o n t a g e , p r e s e n t l y 767. a r e u s ed f o r a g r i c u l t u r e o r a r e undeveloped, 11% a r e i n d u s t r i a l and p o r t , 67, i s r e c r e a t i o n a l , 47, i s r e s i d e n t i a l , and 37, i s f o r t r a n s p o r t ( 4 8 ) . The O f f i c i a l R e g i o n a l P l a n which was adopted i n 1966 by the Lower M a i n l a n d R e g i o n a l P l a n n i n g Board, i t s member m u n i c i p a l i t e s and the P r o v i n c i a l Government, c a l l s f o r a development as i n d i c a t e d i n F i g u r e 2. Land use d e t e r m i n e s t o a g r e a t degree waste c o m p o s i t i o n and water q u a l i t y . M u n i c i p a l z o n i n g t h e r e - f o r e has to be c o n s i d e r e d as a v e r y important p l a n n i n g t o o l w i t h r e g a r d t o water q u a l i t y . P o s s i b l e p r o j e c t s which c o u l d d i s r u p t the e c o l o g y o f th e marshlands and m u d f l a t s i n c l u d e a new f e r r y t e r m i n a l , e x p a n s i o n o f t h e b u l k t e r m i n a l a t Roberts Bank and a second p a r a l l e l runway a t Vancouver I n t e r n a t i o n a l A i r p o r t on Sea I s l a n d (16). New dykes would have t o be c o n s t r u c t e d and l a r g e a r e a s would be f i l l e d , thus f u r t h e r r e d u c i n g v a l u a b l e h a b i t a t l a n d f o r f i s h and w i l d l i f e . A r i v e r i s o f t e n r e g a r d e d as a s e r v a n t f o r i n d u s t r i a l p u r p o ses. B e s i d e s a t r a n s p o r t a t i o n means f o r barges and deep sea v e s s e l s i t has to c a r r y away m i l l i o n s o f g a l l o n s o f waste water e v e r y day. The F r a s e r R i v e r r e c e i v e s waste water from domestic and i n d u s t r i a l s o u r c e s as w e l l as storm water and a g r i c u l t u r a l r u n o f f . Because o f a l a r m i n g l y h i g h b a c t e r i o l o g i c a l counts i n t h e w ater around the beaches o f m e t r o p o l i t a n Vancouver, i t was d e c i d e d to s t o p the dumping o f raw sewage to the sea and t o the r i v e r . I n 1963 the Iona I s l a n d Sewage Treatment P l a n t (STP) s t a r t e d i t s o p e r a t i o n , f o l l o w e d i n 1973 by L u l u I s l a n d STP and A n n a c i s I s l a n d STP i n 1975. These t h r e e p l a n t s r e c e i v e most of t h e i r waste water from r e s i d e n t i a l , commercial, and i n s t i t u t i o n a l s o u r c e s , and p r o v i d e p r i m a r y t r e a t m e n t ( s e d i m e n t a t i o n )  17 and c h l o r i n a t i o n f o r the waste water p r i o r to d i s c h a r g i n g i t to the r i v e r . This can create a problem as c e r t a i n c h l o r i n a t e d organic compounds, t o x i c to f i s h , are formed (e.g. chloramines). D e c h l o r i n a t i o n i s t h e r e f o r e a p p l i e d at L u l u I s l a n d and being considered f o r the Annacis I s l a n d and the Iona p l a n t s . However, d e c h l o r i n a t i o n might not be e f f e c t i v e i n breaking down some compounds such as the group of c h l o r i n a t e d phenyls (31). Primary treatment reduces mainly suspended s o l i d s , but does not remove t o x i c mater- i a l s such as heavy metals, PCB's, and other c h l o r i n a t e d hydrocarbons very e f f e c t i v e l y . A d d i t i o n a l treatment processes w i l l have to be considered as the waste volume of these t o x i c substances increases. At present 83 m i l l i o n gal/day of i n d u s t r i a l e f f l u e n t are d i r e c t l y discharged to the r i v e r . Most of i t i s c o o l i n g water. However, one study done at two p a i n t manufacturing companies revealed that e f f l u e n t standards, set by most m u n i c i p a l i t i e s i n t h e i r by-laws, are not very s t r i c t l y enforced (9). C o n t r o l i s o f t e n only a p p l i e d to remove the suspended s o l i d s , the v i s i b l e f r a c t i o n of p o l l u t a n t s . At present estimates of the q u a n t i t i e s of p o l l u t a n t s that are discharged by i n d u s t r y are not a v a i l a b l e . I n d u s t r i a l wastes vary i n t h e i r composition. I t i s known that a number of i n d u s t r i e s generate small amounts of t o x i c and flammable wastes, some of which are disposed of through sewers and o u t f a l l s (18). A problem of great concern i s the c o n t r o l of storm water r u n o f f . Many storm sewers discharge d i r e c t l y to the r i v e r . Where sewer systems are combined urban r u n o f f receives primary treatment. However, during r a i n storms, when flows are high, most of the incoming waste water i s d i v e r t e d to the r i v e r and r e c e i v e s no treatment at a l l . Westwater's s t u d i e s i n d i - cated that there are considerable q u a n t i t i e s of some trac e metals i n storm water, p a r t i c u l a r l y during the f i r s t f l u s h i n g a f t e r a long p e r i o d of no 18 r a i n f a l l ( 30). A f i r s t s t e p t o c o n t r o l some o f t h e s e p o l l u t a n t s would be the c o n s t r u c t i o n o f h o l d i n g tanks where t h i s f i r s t r u n o f f c o u l d be s t o r e d and g r a d u a l l y be r e l e a s e d l a t e r t o the treatment p l a n t . D e t a i l e d m o n i t o r i n g programs w i l l be r e q u i r e d t o c a l c u l a t e mass bal a n c e s f o r c r i t i c a l groups o f p o l l u t a n t s . Thermal d i s c h a r g e s , p a r t i c u l a r l y t o t r i b u t a r i e s where low flows p r e v a i l , s h o u l d be kept to a minimum as t h i s might r a i s e the temperature l e v e l s which can not be t o l e r a t e d by salmonoid f i s h . A t p r e s e n t o n l y few i n d u s t r i e s take water f o r the purpose o f c o o l i n g d i r e c t l y from the r i v e r . The Water R i g h t s Branch has i s s u e d about 20 p e r m i t s t o t a l l i n g t o about 61 m i l l i o n g a l s / d a y ( 6 8 ) . Because o f i t s h i g h s i l t l o a d i n g s , F r a s e r R i v e r water has to be passed f i r s t through s e t t l i n g ponds i n o r d e r t o p r e v e n t a b r a s i o n and s e d i m e n t a t i o n problems i n the p i p i n g system o f the i n d u s t r y . Water from t h e F r a s e r and i t s t r i b u t a r i e s i s n o t used f o r p u b l i c water s u p p l y anywhere i n the Lower F r a s e r V a l l e y . S u f f i c i e n t water o f b e t t e r q u a l i t y from o t h e r sources i s a v a i l a b l e t o a l l m u n i c i p a l i t i e s . For a g r i c u l t u r a l purposes water i s m a i n l y t a k e n from the t r i b u t a r i e s , s l o u g h s , o r groundwater w e l l s . Only two c a s e s a r e r e g i s t e r e d w i t h t h e Water R i g h t s Branch where water i s taken from the F r a s e r R i v e r f o r i r r i g a t i o n . In some r i v e r b a s i n s a c o n f l i c t o f i n t e r e s t e x i s t s between a g r i c u l t u r e and f i s h e r i e s . F o r example, the bed of the lower C h i l l i w a c k R i v e r (Vedder Canal) has been improved t o a l l o w f o r h i g h e r f l o o d f l o w s . D u r i n g t h e l a s t f l o o d event i n 1975, farmers i n the upper reaches got v e r y u p s e t when water l e v e l s r e c e d e d o n l y s l o w l y because o f the low flow c a p a c i t y o f the n a t u r a l r i v e r bed. They would l i k e t o see the whole r i v e r c a n a l i z e d , something t h a t would d e s t r o y most o f the spawning areas o f v a r i o u s f i s h s p e c i e s . D r a i n i n g o f the marshes, d y k i n g and pumping i n s t a l l a t i o n s have a l r e a d y reduced 19 h a b i t a t o f f i s h and w a t e r f o w l . Damming o f some s m a l l e r r i v e r s to s t o r e water f o r i r r i g a t i o n a l purposes o f t e n submerges spawning grounds. A l s o , t h e s e s t a g n a t i n g waters warm up more r a p i d l y and sometimes show s i g n s o f e u t r o p h i c a t i o n due to n u t r i e n t i n p u t from a g r i c u l t u r a l s o u r c e s . These a r e a s a r e l o s t f o r spawn- i n g s a l m o n o i d s p e c i e s which need c l e a r c o o l waters and u n p o l l u t e d g r a v e l beds. F u t u r e needs might f o r c e people to grow more food i n the F r a s e r V a l l e y . To i n c r e a s e p r o d u c t i v i t y more f e r t i l i z e r s w i l l be a p p l i e d , as w e l l as i n s e c t i c i d e s t o p r o t e c t the crop. T h i s w i l l i n c r e a s e waste l o a d i n g s o f a g r i c u l t u r a l r u n o f f . P r e s e n t l y v e g e t a b l e s and d a i r y f a r m i n g predominate i n the v a l l e y . There a r e some hog and p o u l t r y farms. A n i m a l wastes from t h e s e farms a r e u s u a l l y v e r y c o n c e n t r a t e d and have to be t r e a t e d . O t h e r w i s e a s e r i o u s p o l l u t i o n problem i n a s m a l l t r i b u t a r y r i v e r m i g h t a r i s e . Bad l o g g i n g p r a c t i c e s i n the v a l l e y o f t e n cause a s i l t or d e b r i s problem. S i l t a t i o n o f the spawning grounds i s c o n s i d e r e d t o be one o f the major t h r e a t s t o salmon i n the f u t u r e (36) . D e b r i s i n t h e Lower F r a s e r i s a s e r i o u s problem. The damage done to boats and f i s h n e t s has been e s t i - mated as h i g h as $500,000 per y e a r (15). The r e c r e a t i o n a l a s p e c t o f the F r a s e r R i v e r i s not v e r y s t r o n g a t p r e s e n t . B o a t i n g i s perhaps the major r e c r e a t i o n a l a c t i v i t y , b e s i d e s bar- f i s h i n g , p l e a s u r e d r i v i n g , h o r s e r i d i n g , and p i c n i c k i n g on some dykes. P e o p l e enjo y s e e i n g s uch a mighty r i v e r . I t c a n be e x p e c t e d t h a t w ater q u a l i t y w i l l be v a l u e d more h i g h l y i n the f u t u r e as incomes r i s e and p e o p l e a l s o have more l e i s u r e time t o spend. A t p r e s e n t t h e r e a r e not too many ac c e s s roads t o the w a t e r f r o n t , and the s h o r e l i n e i s p r e d o m i n a n t l y i n d u s - t r i a l i z e d . As o t h e r r e c r e a t i o n r e s o u r c e s a r e used t o c a p a c i t y , more 20 a t t e n t i o n w i l l have to be g i v e n d e v e l o p i n g parks and beaches a l o n g the r i v e r . The e s t u a r y i s famous f o r i t s duck h u n t i n g and f o r v i e w i n g many k i n d s o f b i r d s . There a r e a t l e a s t 88 d i f f e r e n t s p e c i e s o f b i r d s whose common h a b i t a t i s the r i v e r or i t s a d j a c e n t waters and whose major food s o u r c e o r i g i n a t e s i n the e s t u a r y (43). S t i l l o t h e r s use i t as a flyway o r m i g r a t i o n c o r r i d o r . The Lower F r a s e r R i v e r i s known to s u p p o r t the l a r g e s t w i n t e r i n g p o p u l a t i o n o f w a t e r f o w l i n Canada. T h i r t y - e i g h t s p e c i e s o f f i s h i n h a b i t t h e Lower F r a s e r R i v e r . They a r e m i g r a t o r y , s e m i - m i g r a t o r y or r e s i d e n t . The F r a s e r and i t s e s t u a r y a l s o support many o t h e r a q u a t i c organisms which s e r v e as f o o d to the organisms h i g h e r up i n the food c h a i n . The c r a b f i s h e r y i n the F r a s e r e s t u a r y gave f i s h e r m e n an income o f $281,000 i n 1973 and r e p r e s e n t e d 20.57. o f the t o t a l B.C. c a t c h ( 1 6 ) . There i s commercial, r e c r e a t i o n a l , and I n d i a n food f i s h - i n g . By f a r the most important f i s h a r e the f i v e s p e c i e s o f salmon, r e s i - dent i n the P a c i f i c r e g i o n : sockeye, pink, chum, coho, and c h i n o o k salmon. They a r e e s p e c i a l l y p r i z e d by B r i t i s h Columbians, and p e o p l e even o f t e n o v e r e s t i m a t e t h e i r importance i n r e l a t i o n t o o t h e r major s e c t o r s o f B.C.'s economy (4 9 ) . D. The Salmon Resource The F r a s e r R i v e r has the second l a r g e s t salmon r u n i n the w o r l d ( o n l y the Yukon R i v e r s u p p o r t s a b i g g e r r u n ) . There i s a c o n t i n u o u s up- stream m i g r a t i o n o f a d u l t f i s h a l l y e a r around. P i n k salmon r e t u r n s have averaged n e a r l y s i x m i l l i o n f i s h i n every odd numbered y e a r s i n c e 1957. V i r t u a l l y no f i s h e n t e r the r i v e r to spawn i n even numbered y e a r s ( 4 3 ) . Next i n n u m e r i c a l importance come the sockeye salmon w i t h between one and 21 t e n m i l l i o n a d u l t f i s h (depending on the c y c l e y ear) and an average of 45 m i l l i o n j u v e n i l e s . Some h a l f m i l l i o n chum a d u l t s move up the r i v e r and about 27 m i l l i o n smolts move downstream. The F r a s e r R i v e r c h i n o o k salmon support important commercial, r e c r e a t i o n a l , and I n d i a n food f i s h e r i e s b o t h near o r i n the r i v e r as w e l l as a l o n g the c o a s t . The average commercial c a t c h has been e s t i m a t e d a t some 480,000 f i s h . Coho salmon i s a l s o h i g h l y v a l u e d by commercial and s p o r t s f i s h e r m e n . A minimum c a t c h o f 500,000 f i s h i s e s t i m a t e d to o r i g i n a t e from the F r a s e r R i v e r spawning grounds. A l t o g e t h e r , the salmon r e p r e s e n t s an a n n u a l commercial c a t c h v a l u e o f $73 m i l l i o n (1973 p r i c e s ) , a r e c r e a t i o n a l v a l u e o f about $186 m i l l i o n , and a p r e s e r v a t i o n v a l u e o f $101 m i l l i o n , a c c o r d i n g t o a h o u s e h o l d s u r v e y by Environment Canada, F i s h e r i e s and Marine S e r v i c e ( 4 1 ) . The commercial f i s h e r y has put h i g h c a p i t a l investments i n i t s f i s h i n g f l e e t and p r o c e s s - i n g p l a n t s . The e x p e n d i t u r e s by commercial and s p o r t s f i s h e r m e n to m a i n t a i n t h e i r boats and f i s h i n g gear support an important s e r v i c e i n d u s t r y . I t i s p l a n n e d t o i n c r e a s e the c u r r e n t a n n u a l salmon p r o d u c t i o n through an enhancement program which would i n v o l v e the c o n s t r u c t i o n o f a r t i f i c i a l spawning c h a n n e l s , h a t c h e r i e s , i n c u b a t i o n boxes, and v a r i o u s s t ream improvement measures. P r o b a b l e investments would t o t a l $250 to $300 m i l l i o n t o be spent over the next 15-20 y e a r s f o r programs i n v a r i o u s salmon r i v e r s o f the P a c i f i c c o a s t (46). B e f o r e the d i s a s t r o u s r o c k s l i d e i n 1913 which made the passage a t H e l l ' s Gate i n the F r a s e r Canyon i m p o s s i b l e f o r upstream m i g r a t i n g sockeye salmon, the sockeye r u n i n t h e F r a s e r R i v e r had y i e l d e d a r e c o r d c a t c h o f over 30 m i l l i o n f i s h . One run, t h e p r e v i o u s dominant 01 c y c l e , f e l l to a v e r y low l e v e l i n s u c c e e d i n g y e a r s and has never r e c o v e r e d s i n c e . C o n s t r u c t i o n o f fishways a t v a r i o u s p o i n t s i n the F r a s e r Canyon by the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission 22 together w i t h a f i n e l y tuned management program has helped to g r a d u a l l y increase the t o t a l stock of most c y c l e years again. I t i s hoped that through f u r t h e r enhancement programs the Fraser R i v e r may see the o l d record runs someday again. However, enhancement without p r e s e r v a t i o n of present water q u a l i t y , which i s already q u i t e low i n some t r i b u t a r i e s and areas of the estuary, w i l l most l i k e l y be a f a i l u r e . Salmon are very s e n s i t i v e f i s h and cannot adapt to higher r i v e r temperatures or i n c r e a s i n g p o l l u t a n t loadings. P o l l u t i o n may a l s o threaten i t s food organisms. Even i f we keep the up- stream spawning grounds of the salmon i n p e r f e c t l y good c o n d i t i o n , the salmon runs might s t i l l decrease as water q u a l i t y i n the Lower Fraser and the estuary d e t e r i o r a t e s . The t r a n s i t i o n from f r e s h to s a l i n e water i s a very c r i t i c a l stage i n a salmon's l i f e i n v o l v i n g c o n s i d e r a b l e p h y s i o l o g i c a l adjustment. I f f u r t h e r s t r e s s e s i n the form of i n c r e a s i n g p o l l u t i o n l e v e l s are a p p l i e d there, e f f e c t s on the f i s h may be d e t r i m e n t a l w i t h regard to h i s s u r v i v a l chances i n the ocean. A decrease i n water q u a l i t y w i l l show i t s e f f e c t s on a f i s h popu- l a t i o n . As f i s h are a major user of the Fraser R i v e r water and have p a r t i c u - l a r requirements w i t h regard to water q u a l i t y , i t was decided to i l l u s t r a t e the e f f e c t s of p o l l u t i o n on salmon. A p a r t i c u l a r sockeye salmon run of the Fraser system was chosen s i n c e most of the numerical knowledge that we have of the sockeye salmon's l i f e c y c l e i s r e l a t e d to t h i s run. 23 CHAPTER I I I L I F E CYCLE OF THE SOCKEYE SALMON A. I n t r o d u c t i o n The c u r v e s d e s c r i b e d i n t h i s c h a p t e r were based on i n f o r m a t i o n which was o b t a i n e d from the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commis- s i o n . These c u r v e s s h o u l d not be i n t e r p r e t e d as the r e s u l t s o f a s t r i c t s t a t i s t i c a l a n a l y s i s w i t h a n a l y t i c a l l y d e r i v e d c o n f i d e n c e l i m i t s , but r a t h e r as a g e n e r a l i n d i c a t i o n o f v a l u e s observed i n the C h i l k o R i v e r system. More emphasis was p l a c e d on d e m o n s t r a t i n g a method t o p r o c e s s such i n f o r m a - t i o n than on n u m e r i c a l e x a c t i t u d e . The C h i l k o R i v e r sockeye s t o c k i s the second l a r g e s t i n the F r a s e r R i v e r system. I n two y e a r s out of each f o u r about 25 to 65% o f the c a t c h o f sockeye salmon from the e n t i r e F r a s e r R i v e r system o r i g i n a t e s from the C h i l k o R i v e r ( 7 1 ) . The C h i l k o R i v e r s t o c k i s the most t h o r o u g h l y s t u d i e d r u n i n the F r a s e r system. S i n c e 1949 the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission (IPSFC), e s t a b l i s h e d i n 1937 by t r e a t y between Canada and the U n i t e d S t a t e s , has conducted d e t a i l e d s u r v i v a l measurements. The numbers of spawners, d e p o s i t e d eggs, emerged f r y , s m o l t s , and r e t u r n i n g a d u l t s a r e e s t i m a t e d each y e a r . The a d u l t s mature p r i m a r i l y as 4 - y e a r - o l d f i s h , c a u s i n g a 4 y e a r c y c l i c abundance p a t t e r n to dominate, but w i t h i n c y c l e s abundance v a r i e s s u b s t a n t i a l l y . M o r t a l i t y r a t e s i n the d i f f e r e n t l i f e s t a g e s may v a r y s i g n i f i c a n t l y (17,33,34,52,69). Sheehan (55) g i v e s a summary and d i s c u s s e s the u n c e r t a i n t y f a c t o r s i n each l i f e s t a g e f o r Skeena R i v e r sockeye. I t i s p o s s i b l e to d e velop f u n c t i o n a l r e l a t i o n s h i p s t o de- s c r i b e t h e s e l i f e s t a g e s u s i n g observed d a t a . The range o f u n c e r t a i n t y can 24 be i n d i c a t e d by upper and lower boundary l i n e s . F i g u r e 5 t o F i g u r e 9 show such r e l a t i o n s h i p s f o r the C h i l k o R i v e r sockeye. The cur v e s a r e used as i n p u t i n a p r o b a b i l i s t i c model which i s d e s c r i b e d i n C h a p t e r IV. The graphs p r e s e n t e d i n t h i s paper were develop e d w i t h the h e l p from the IPSFC. The l i f e c y c l e o f the C h i l k o sockeye salmon and r e l a t i o n s h i p s between the numbers e n t e r i n g and l e a v i n g each st a g e a r e d e s c r i b e d below. B. The C h i l k o R i v e r Sockeye C h i l k o Lake l i e s between the P a c i f i c and the C h i l c o t i n ranges o f the Coast Mountains ( F i g u r e 3 ) . A d u l t sockeye m i g r a t e o v e r 380 m i l e s from the mouth o f the F r a s e r t o the spawning grounds l o c a t e d a t the o u t l e t o f C h i l k o Lake ( F i g u r e 4) t o d e p o s i t t h e i r eggs i n the g r a v e l o f the r i v e r bottom. The peak spawning o f t h i s r u n oc c u r s i n l a t e September. I n the f o l l o w i n g s p r i n g f r y h a t c h from the eggs, emerge and l a t e r m i g r a t e upstream i n t o the l a k e . Smolt m i g r a t i o n takes p l a c e i n A p r i l o r May a f t e r one o r two y e a r s o f l a k e r e s i d e n c e . The sockeye remain i n t h e sea from 1% t o 3% ye a r s b e f o r e m a t u r i n g and r e t u r n i n g t o t h e i r n a t a l stream. P a s s i n g through the c o a s t a l waters they a r e h a r v e s t e d by Canadian and U n i t e d S t a t e s f i s h e r - men w i t h g i l l n e t s , purse s e i n e s , or by t r o l l i n g . When m i g r a t i n g up the r i v e r n a t i v e I n d i a n s c a t c h a p o r t i o n o f the escapement f o r food. As i n most o t h e r r a c e s o f F r a s e r sockeye, a l a r g e ( o r "dominant") run r e t u r n s e v e r y f o u r t h y e a r . The C h i l k o s t o c k has two s m a l l e r ( " o f f - y e a r " ) runs and a medium s i z e d r u n ("subdominant") between dominant y e a r s . When d e v e l o p i n g the cur v e s the ranges o f the t h r e e r u n s i z e s were p i e c e d t o g e t h e r t o a l l o w a c o n t i n u o u s a n a l y s i s . The f i v e l i f e s t a g e s were chosen w i t h the i n t e n t i o n o f i n c l u d i n g p o l l u t i o n e f f e c t s l a t e r i n the model. From a b i o l o g i c a l p o i n t o f view, the f i r s t r e l a t i o n s h i p r e l a t i n g t h e number o f  4. - Chilko Lake, Chilko River, and spawning grounds of sockeye salmon 27 female spawners to the escapement might not be considered as a l i f e stage. However, as the s u r v i v a l of future salmon generations depends on the safe passage of ad u l t salmon through i n c r e a s i n g l y p o l l u t e d waters of the Lower Fraser R i v e r , t h i s " l i f e stage" was incorporated i n t o the model. B. 1 . R e l a t i o n s h i p Between Escapement and Female Spawners In convention waters catch and escapement i s re g u l a t e d by the IPSFC. At the beginning of the f i s h i n g season a r e t u r n f i g u r e i s p r o j e c t e d f o r each stock based on the number of smolts m i g r a t i n g to the sea, the number of jacks (mature 3 - y e a r - o l d males) that returned the year before, and other data. A target escapement i s e s t a b l i s h e d . The a c t u a l escapement i s managed on a day to day b a s i s . The escapement f i g u r e s are estimated by means of t e s t f i s h i n g , and more r e c e n t l y by echo sounding i n the Lower Fraser R i v e r . The spawning p o p u l a t i o n i s enumerated u s i n g the Peterson mark recapture method. A f t e r they have spawned the salmon d i e . Between 2 0 7 o and 4 0 7 o of the carcasses are recovered and the tags are counted. The p r o p o r t i o n of female spawners and t h e i r success i n spawning i s determined. Counting the tags the t o t a l p o p u l a t i o n number can be estimated u s i n g the r e l a t i o n s h i p N = H i t where N = t o t a l p o p u l a t i o n n = number of recovered f i s h T = number of i n i t i a l tags t = number of recovered tags The p r o b a b i l i t y band i n Figure 5 accounts f o r u n c e r t a i n t y f a c t o r s such as v a r i a b i l i t y i n sex r a t i o , Indian catch, and the m o r t a l i t y en route to spawning grounds. The p o r t i o n of females out of the t o t a l escapement can vary between 4 9 7 , and 6 0 7 , ( 2 9 , 7 1 ) w i t h an average of 5 3 7 , to 5 7 7 » ( 2 0 ) . G i l l S u — U p p e r confidence limit 5 M — Medium value S L — Lower confidence limit Chosen Matrix [l6 x 15] 100 200 300 400 500 620 Escapement in thousands RELATIONSHIP BETWEEN ESCAPEMENT AT THE MOUTH OF THE RIVER AND FEMALE SPAWNERS REACHING SPAWNING GROUNDS. 29 n e t t i n g , f o r example, i s sex s e l e c t i v e , as males a r e more prone t o t h i s form o f c a p t u r e . The I n d i a n removal can v a r y between 15%, and 25% depending on the s i z e o f the run. The curves i n F i g u r e 5 were c o n s t r u c t e d u s i n g the p u b l i s h e d escapement d a t a (29) and the extreme v a l u e s f o r the sex r a t i o and the I n d i a n h a r v e s t r a t e . A change i n s l o p e f o r about 240,000 f i s h was made, as the p r o p o r t i o n caught by I n d i a n s was l e s s a t h i g h e r escapements. En- v i r o n m e n t a l e f f e c t s on t h i s l i f e s t a g e can be caused by s m a l l l a n d s l i d e s which t e m p o r a r i l y o b s t r u c t the m i g r a t i o n r o u t e . B.2. R e l a t i o n s h i p Between Female Spawners and D e p o s i t e d Eggs F e c u n d i t y i s a f u n c t i o n o f female l e n g t h . A r e g r e s s i o n a n a l y s i s r e l a t i n g t o f e c u n d i t y and body l e n g t h i s done f o r a sample o f 50 females each y e a r . Spawning s u c c e s s i s e x p r e s s e d i n terms o f " e f f e c t i v e " female spawners. T h i s i s based on the eggs r e t a i n e d i n the c a r c a s s e s of the r e - c o v e r e d dead females. However, not a l l females s u c c e s s f u l l y spawn due t o s e v e r a l p o s s i b l e r e a s o n s . Water temperature and b a c t e r i a l i n f e c t i o n may p l a y an important r o l e i n the pre-spawning m o r t a l i t y problem. O t h e r f a c t o r s c o u l d become i m p o r t a n t such as exposure to p o l l u t e d waters d u r i n g the up- stream m i g r a t i o n . V a r i a t i o n i n success o f spawning and f e c u n d i t y i s not l a r g e as i n d i c a t e d by the r e l a t i v e l y narrow p r o b a b i l i t y band i n F i g u r e 6. Spawning escapements a t C h i l k o R i v e r ( e f f e c t i v e females) have ranged from 10,000 t o 328,000 and averaged 109,000 d u r i n g the p a s t 25 y e a r s ( 2 0 ) . B.3. R e l a t i o n s h i p Between the Number o f D e p o s i t e d Eggs and the Number o f F r y I t i s n e c e s s a r y t o d i s c r i m i n a t e between the c a l c u l a t e d egg d e p o s i - t i o n from the a c t u a l d e p o s i t i o n . As female spawners w h i c h a r r i v e l a t e r w i l l 800 Chosen Matrix [15 x 16] 50 100 150 200 250 Female spawners in thousands 300 FIG. 6 FEMALE SPAWNERS VS. EGGS DEPOSITED o 31 o f t e n d i g out eggs deposited by e a r l i e r spawning females, the number of a c t u a l eggs i n the g r a v e l a t completion of spawning w i l l be lower than estimated. In the case of overcrowding t h i s e f f e c t can be very s u b s t a n t i a l and has a compensatory m o r t a l i t y e f f e c t . High escapement numbers t h e r e f o r e can cause damage to the process of egg d e p o s i t i o n on the l i m i t e d area of the spawning ground. There i s a c a r r y i n g c a p a c i t y f o r each spawning ground. Environmental f a c t o r s such as water flow, water temperature, s e d i - ment load of the stream, concentrations of NH4, NC>2, NO3, CG^, and oxygen, as w e l l as i c e formation a l l a f f e c t the number of f r y that w i l l hatch from the eggs. As C h i l k o Lake i s o l i g o t r o p h i c water q u a l i t y p r e s e n t l y i s not a problem. In the w i n t e r or c o l d nights r a d i a t i o n a l c o o l i n g of bottom rocks may r e s u l t i n the formation of anchor i c e . Anchor i c e prevents the ex- change between stream water and i n t e r g r a v e l flow. The eggs may not o b t a i n enough oxygen and ther e f o r e d i e . Low flow c o n d i t i o n s can r e s u l t i n the f r e e z i n g or d e s s i c a t i o n of eggs deposited on the higher s t r e t c h e s of the gravel banks. In the past 25 years the s u r v i v a l r a t e f o r the eggs-to-fry stage has v a r i e d between 47. and 147. (69) . The p r o b a b i l i t y band i s i n d i c a t e d i n Figure 7. B. 4. R e l a t i o n s h i p Between the Number of Fry and the Number of Smolt A f t e r emerging from the stream g r a v e l the C h i l k o sockeye f r y are c a r r i e d downstream to a quiet water area where they remain f o r a short p e r i o d of time. Fry then migrate upstream along the shores i n low v e l o c i - t i e s i n t o the lake. The number of f r y was determined f o r a number of years using a photographic technique. The camera was i n s t a l l e d above the water  33 surface and a white board i n the r i v e r bed was used as a c o n t r a s t medium. More r e c e n t l y an index count has been used. V i s u a l estimates are made at r e g u l a r i n t e r v a l s . These counts are then r e l a t e d to past estimates and extrapolated to a t o t a l f r y estimate. Once sockeye f r y have entered the r e a r i n g lake, two main f a c t o r s appear to govern the s u r v i v a l r a t e : food supply and predators. Food supply may be most important when the f r y enter the lake. I f they enter the lake very e a r l y i n the year there might not be s u f f i c i e n t food a v a i l a b l e to them as the p r o d u c t i v i t y of the lake increases w i t h i n c r e a s i n g temperature and s o l a r r a d i a t i o n . Goodlad e_t al_. (20) hypothesized that v a r i a t i o n i n the length of the growing p e r i o d and i n i n i t i a l r e a r i n g temperature have greater i n f l u e n c e s on growth than other f a c t o r s . The f r y f i r s t feed on emerging i n s e c t s and l a t e r on crustacean zooplankton. In the o l i g o t r o p h i c C h i l k o Lake there i s a comparatively low standing crop of zooplankton as has been measured f o r s e v e r a l years. With regard to predation, the s i z e of the predator compared to i t s prey i s most important. Apparently, C h i l k o Lake has a very low p o p u l a t i o n of predators which feed on the sockeye f r y . As a consequence the s u r v i v a l r a t e i n t h i s l i f e stage i s very h i g h and has ranged from about 32% to 73%, as i n d i c a t e d i n the p r o b a b i l i t y band of Figure 8. B. 5. R e l a t i o n s h i p Between the Number of Smolts and the Number of Returning Adults A f t e r one year of lake residence, most of the young sockeye begin t h e i r journey to the ocean. The number of migrants i s enumerated photo- g r a p h i c a l l y . The sockeye smolts apparently move f a i r l y q u i c k l y out to the open sea a f t e r reaching the r i v e r mouth. The s u r v i v a l r a t e i n the ocean Chosen Matrix [lOX 1 0 ] 35 appears to depend on some e n v i r o n m e n t a l f a c t o r s p r e v a i l i n g i n the r i v e r d u r i n g m i g r a t i o n time. C o r r e l a t i o n a n a l y s i s by W i l l i a m s (69) i n d i c a t e s a r e l a t i o n s h i p between r i v e r d i s c h a r g e d u r i n g smolt m i g r a t i o n and subsequent marine s u r v i v a l . Water q u a l i t y c o u l d become o f c r i t i c a l importance i f the p o l l u t i o n l e v e l c o n t i n u e s to i n c r e a s e i n the e s t u a r y . There a l r e a d y e x i s t s a h i g h e r p o l l u t i o n t h r e a t i n the N o r t h Arm r e a c h e s . I t i s b e l i e v e d t h a t the numbers o f m i g r a t i n g smolts a r e p r e s e n t l y d i v i d e d between the arms i n p r o p o r t i o n t o t h e i r r e s p e c t i v e flows (43). The s u r v i v a l chances of the young smolt a g a i n s t i t s p r e d a t o r s i n the ocean depend v e r y much on the s i z e o f the sockeye smolt compared t o the s i z e o f the p r e d a t o r . Growth r a t e thus becomes a s i g n i f i c a n t e f f e c t i n m o r t a l i t y r a t e . T h e r e f o r e , i t i s q u i t e important how f a r the f e e d i n g grounds a r e away from the mouth o f the r i v e r . Parsons (62) found i n s i m u l a - t i o n s t u d i e s of p h y t o p l a n k t o n growth i n the S t r a i t o f G e o r g i a t h a t p o l l u - t i o n o f the c o a s t a l waters (e.g. i n t h e form o f c o a l d u s t from a new c o a l t e r m i n a l ) c o u l d change the l i g h t a b s o r p t i o n and thus reduce the growth o f the p h y t o p l a n k t o n i n an a r e a which can be r e a c h e d by the young salmonoids f a i r l y q u i c k l y ( p h y t o p l a n k t o n i c organisms a r e the f i r s t s t e p i n a food c h a i n which s u p p o r t s salmon). The f a c t o r s which might have an i n f l u e n c e on the s u r v i v a l o f the salmon i n the ocean a r e not w e l l u n d e r s t o o d . I t i s not s u r p r i s i n g t h a t the p r o b a b i l i t y band i s v e r y wide ( F i g u r e 9) showing a s u r v i v a l r a t e t h a t can v a r y between 17, and 227.. As the g e n e t i c s of the C h i l k o Lake s t o c k have a p p a r e n t l y not changed s i g n i f i c a n t l y o v e r the p a s t 25 y e a r s , a l l the c o l l e c t e d d a t a a r e o f e q u a l importance. In the f o l l o w i n g c h a p t e r a method i s o u t l i n e d f o r u s i n g t h i s i n f o r m a t i o n i n a model t h a t i n c o r p o r a t e s the e f f e c t s o f u n c e r t a i n t y . With Chosen Matrix [lO X 15] 20 30 40 Smolts in millions FIG. 9 SMOLTS MIGRATING TO THE OCEAN VS. RETURNING ADULT SALMON. 00 t h i s model changes i n the stock/recruitment r e l a t i o n s h i p can be estimated given that the c o n d i t i o n s f o r s u r v i v a l i n the above l i f e stages change. Thus, p o s s i b l e consequences of enhancement techniques can be evaluated as w e l l as p o t e n t i a l l y d e t r i m e n t a l e f f e c t s due to decreasing water q u a l i t y . 38 CHAPTER IV A MODEL USING DATA RECORDS WHERE AVAILABLE AND JUDGMENT OF EXPERTS A. I n t r o d u c t i o n Many e f f o r t s have been made i n the p a s t to model the salmon l i f e c y c l e (32,33,34,35,52,67). The e x i s t i n g models c a n be viewed as d e t e r m i n - i s t i c w i t h s t o c h a s t i c components to account f o r random p r o c e s s e s such as e n v i r o n m e n t a l v a r i a b i l i t y . L a r k i n (32) d e s c r i b e d h i s model as one which produces a spectrum o f answers - because o f the f l u c t u a t i o n o f the random f a c t o r s - and thus i t i s " v i r t u a l l y u n t e s t a b l e u s i n g h i s t o r i c a l d a t a . " He a l s o p o i n t e d out t h a t i n most cases we would tend t o argue t h a t a model which reproduces an o b s e r v e d p a t t e r n i s good, whereas i f the p a t t e r n appears o n l y i n f r e q u e n t l y , "one i s l e f t t o d e c i d e whether the model i s 'poor' o r whether the p a r t i c u l a r sequence of e n v i r o n m e n t a l e f f e c t s t h a t o c c u r r e d n a t u r a l l y was i n d e e d a q u i t e u n u s u a l sequence t h a t pushed the system i n an u n l i k e l y d i r e c t i o n " ( 3 5 ) . I n t r o d u c t i o n o f more b u i l d i n g b l o c k s and f u r t h e r e q u a t i o n s to de- s c r i b e i n t e r a c t i o n s does not seem to i n c r e a s e the p r e d i c t i v e c a p a c i t y o f a model. Random f a c t o r s seem to govern the p r o c e s s c h a i n and t h e r e f o r e we can expect a spectrum o f answers o f v a r y i n g p r o b a b i l i t i e s . An escape from t h i s dilemma i s r a t h e r obvious and has been proposed by L a r k i n h i m s e l f (35). " . . . a v o i d the t h e o r e t i c a l assumptions, a c c e p t the p a s t as e v i d e n c e o f the a s s o c i a t i o n between s t o c k and r e c r u i t m e n t and p r o c e e d on the b a s i s t h a t the same w i l l happen i n the f u t u r e . T h i s c o r r e l a t i v e k i n d o f approach makes no p r e t e n c e a t u n d e r s t a n d i n g nor p r e d i c t i o n beyond the a v a i l a b l e range 39 of observation. I t has the merit of s i m p l i c i t y and w i t h modern computing f a c i l i t i e s , presents no d i f f i c u l t i e s of e m p i r i c a l a n a l y s i s . " Most of the e x i s t i n g data are on stock and recruitment. ( I n the f o l l o w i n g these w i l l be termed escapement and r e t u r n i n g a d u l t s . ) A smooth curve can be f i t t e d through the data points and an e m p i r i c a l p r o b a b i l i t y d i s t r i b u t i o n of recruitment f o r each conceivable spawning stock can be c a l c u l a t e d . Walters (67) argued that t h i s p r o b a b i l i t y d i s t r i b u t i o n should be approximated by a lognormal d i s t r i b u t i o n f u n c t i o n as environmental e f f e c t s are m u l t i p l i c a t i v e i n nature and can be considered to be more or l e s s independent of one another. (The lognormal d i s t r i b u t i o n f u n c t i o n i s discussed more e x p l i c i t l y i n Appendix 1.) A l s o , R i c k e r (52) had pointed out that the d i s t r i b u t i o n f u n c t i o n should be skewed i n shape. He used various t h e o r e t i c a l r e p roduction curves f o r the mean curves and superim- posed randomly-occurring environmental v a r i a b i l i t y by u s i n g a random s e l e c t i o n of m u l t i p l i e r s whose frequencies were normally d i s t r i b u t e d . This procedure r e s u l t s i n an asymmetrical d i s t r i b u t i o n of the progeny numbers. E x i s t i n g data on stock/recruitment curves have been analysed f a i r l y w e l l f o r the Skeena R i v e r sockeye salmon (56,57,67), and a lognormal d i s t r i b u t i o n seems to describe the observed f l u c t u a t i o n s a p p r o p r i a t e l y . For the purpose of t h i s t h e s i s the author has attempted to go one step f u r t h e r and study the e f f e c t s of changing environmental c o n d i t i o n s on each l i f e stage of the salmon c y c l e . This procedure i s promising f o r a number of a p p l i c a t i o n s such as i n the study of enhancement techniques which improve the s u r v i v a l rates at any one stage of the salmon l i f e c y c l e , or as i n the present study, i n the s i m u l a t i o n of the o v e r a l l e f f e c t s of p o l l u t i o n i f poor water q u a l i t y c o n d i t i o n s a f f e c t one l i f e stage i n p a r t i c u l a r . In Chapter I I I the f u n c t i o n a l r e l a t i o n s h i p s f o r each l i f e stage f o r 40 the C h i l k o R i v e r salmon run were p r e s e n t e d i n the form o f graphs. I t has been p o i n t e d out t h a t the dat a base i s s t i l l q u i t e s m a l l ( e s t i m a t e s have o n l y been made s i n c e 1949) and c e r t a i n d i f f i c u l t i e s e x i s t i n d e r i v i n g the mean, upper, and lower c u r v e s . For the f o l l o w i n g d i s c u s s i o n i t i s assumed t h a t t h e s e graphs r e p r e - s e n t the b e s t i n f o r m a t i o n p r e s e n t l y a v a i l a b l e f o r the C h i l k o R i v e r s t o c k . They d e s c r i b e our p r e s e n t u n d e r s t a n d i n g o f each l i f e s t a g e and t h e u n c e r - t a i n t i e s a s s o c i a t e d w i t h each o f them a r e i n d i c a t e d by the w i d t h o f the band between the upper and lower c o n f i d e n c e l i n e s . The next s t e p i s t o i n t e g r a t e the f i v e l i f e s t a g e s i n t o a s i n g l e s t o c k / r e c r u i t m e n t c u r v e . (We s h a l l r e f e r t o t h i s l a t e r as an expe c t e d r e t u r n g i v e n a c e r t a i n escapement.) Then one can change the s u r v i v a l r a t e i n each l i f e s t a g e thus s i m u l a t i n g enhancement or p o l l u t i o n e f f e c t s and s t u d y the r e l a t i v e changes i n r e t u r n i n g a d u l t numbers. By b e t t e r c o n t r o l t e c h n i q u e s we might a l s o be a b l e t o narrow the u n c e r t a i n t y band i n some l i f e s t a ge. T h i s would r e s u l t i n a reduced u n c e r t a i n t y o f the f i n a l out- come. We now want t o f o r m a l i z e t h i s p r ocedure i n ma t h e m a t i c a l terms. B. U n c e r t a i n t y and E x p e c t e d R e t u r n U n c e r t a i n t y i s o f t e n d e s c r i b e d by w e i g h i n g p o s s i b l e v a l u e s w i t h the l i k e l i h o o d o f t h e i r o c c u r r e n c e . The same can be done i n p r e d i c t i n g a salmon r e t u r n . Even i f we were a b l e to f o r m u l a t e a l l i n t e r a c t i o n s as con- c i s e l y as p o s s i b l e we would s t i l l have t o account f o r random p r o c e s s e s such as p r e d a t i o n or c h a n g i n g e n v i r o n m e n t a l c o n d i t i o n s . A l l p r e d i c t e d ( o r ex- pected) v a l u e s s h o u l d t h e r e f o r e have p r o b a b i l i t i e s a s s o c i a t e d w i t h them. The e x p e c t e d v a l u e E(X) o f a d i s c r e t e random v a r i a b l e X i s d e f i n e d as: E(X) = E X. p (X.) (A) 1 x 1 41 where a r e p o s s i b l e v a l u e s f o r the v a r i a b l e x and p x a r e t h e i r r e s p e c - t i v e l i k e l i h o o d s . I f we s p e c i f y r e t u r n c l a s s e s we would l i k e t o know the p r o b a b i l i t y o f r e t u r n i n g salmon b e i n g i n a c e r t a i n c l a s s g i v e n a f i x e d escapement v a l u e . A s i m p l e example w i l l i l l u s t r a t e t h i s : G i v e n an escapement of 420,000 a d u l t salmon, how many a d u l t s w i l l r e t u r n i n f o u r y e a r s time? We cannot ask f o r an e x a c t number but r a t h e r a r e i n t e r e s t e d t o know the p r o b a b i l i t i e s t h a t 1.0 t o 1.2, 1.2 t o 1.4, 1.4 t o 1.6 m i l l i o n salmon, e t c . , w i l l r e t u r n . For the x^ we take the median v a l u e of each r e t u r n c l a s s . Our model w i l l c a l c u l a t e t h e p r o b a b i l i t i e s o f t h e i r o c c u r r e n c e . How do we i n c l u d e the p r o b a b i l i s t i c n a t u r e o f the problem i n our model? As an example l e t us take the graph which i l l u s t r a t e s the r e l a t i o n - s h i p between the number of f r y h a t c h e d from the eggs and the number o f smolts l e a v i n g the l a k e a f t e r f e e d i n g f o r about a y e a r ( F i g u r e 8 ) . The b i o l o g i s t has done a r e g r e s s i o n a n a l y s i s on h i s o b s e r v e d d a t a and has g i v e n us a l i n e a r f u n c t i o n d e s c r i b i n g t h i s salmon l i f e s t a g e . I n a d d i t i o n t o f i t t i n g a curve t o h i s mean v a l u e s , he has i n d i c a t e d t h e range o f p o s s i b l e v a l u e s which can be e i t h e r o b served extreme d a t a p o i n t s o r b e s t e s t i m a t e s at t h a t time. I t i s common i n a p p l i c a t i o n s o f p r o b a b i l i t y t h e o r y t o speak o f the "one-, two-, and t h r e e sigma bounds" o f a random v a r i a b l e , thus c o n s i d e r i n g the b o u n d a r i e s which c o v e r 657,, 957,, or 99.77, o f a l l o b s e r v e d v a l u e s . A f t e r some e x p e r i m e n t a t i o n w i t h the model i t was d e c i d e d t o use two s t a n d a r d d e v i a t i o n s t h e r e b y assuming t h a t 957. o f a l l p o s s i b l e events l i e between the g i v e n c o n f i d e n c e l i m i t s . Hershman (25) and Sheehan (55) had used i n t h e i r m o d e l i n g t h r e e s t a n d a r d d e v i a t i o n s and a skew normal d i s t r i - 42 b u t i o n f u n c t i o n . I t was f e l t f o r t h i s study that imperfect knowledge of the numerical values i n each l i f e stage would not warrant such p r e c i s i o n . The next step i s to f i n d a p r o b a b i l i t y d i s t r i b u t i o n f u n c t i o n which best describes the data observed between the confidence l i n e s . In the case where we have enough data i t can be analysed and f i t t e d t o a common type of d i s t r i b u t i o n f u n c t i o n such as a normal, lognormal, or Gamma d i s t r i b u t i o n . This d i s t r i b u t i o n f u n c t i o n then can be used f o r a l l f u t u r e analyses. C. Choice of a D i s t r i b u t i o n Function I t i s o f t e n very convenient to use a p a r t i c u l a r d i s t r i b u t i o n because i t i s w e l l known, w e l l tabulated, and e a s i l y worked w i t h . In many s i t u a - t i o n s we are i n c l i n e d to t r y a normal d i s t r i b u t i o n f i r s t because of the ease i n working w i t h i t . E s p e c i a l l y i n the case where we have l i t t l e or no data, a normal d i s t r i b u t i o n i s o f t e n adopted as a "not unreasonable" f i r s t model. For the C h i l k o Lake stock only s l i m data have been c o l l e c t e d so f a r . To mathematically derive any d i s t r i b u t i o n f u n c t i o n from these would have been premature. A l s o , the accuracy of the data points could not be guaranteed. With the echo sounding technique r e p l a c i n g the photographic enumeration procedure more data w i l l become a v a i l a b l e w i t h i n the next years from a number of lake systems. A frequency a n a l y s i s of the data from these l i f e stages could then be done and a p r o b a b i l i t y d i s t r i b u t i o n could be derived. As t h i s paper i s mainly concerned to demonstrate a methodology where new i n f o r m a t i o n can e a s i l y be incorporated, the simple case of a normal d i s t r i b u t i o n was chosen. However, we have to be aware that t h i s choice w i l l i n f l u e n c e our r e s u l t s to a c e r t a i n extent. We should therefore not compare simulated r e s u l t s w i t h observed data i n a too c r i t i c a l way. 43 The s i m u l a t e d numbers have o n l y i l l u s t r a t i v e v a l u e and c a n o n l y r e f l e c t r e a l i t y i f the i n p u t i n t o the model were t o be improved. In a l a t e r s t a g e of t h i s work i t was f e l t t h a t a l o g n o r m a l d i s t r i - b u t i o n would have p r o b a b l y d e s c r i b e d the v a r i a b i l i t y i n a b e t t e r way. A d i s c u s s i o n o f the two d i s t r i b u t i o n f u n c t i o n s has t h e r e f o r e been added t o the Appendix. When a normal model i s adopted, i t s h o u l d be noted t h a t i t s v a l i d i t y may break down o u t s i d e the r e g i o n about i t s mean. T a i l s o f the d i s t r i b u t i o n a r e much more s e n s i t i v e to e r r o r s i n the model f o r m u l a t i o n t h a n the c e n t r a l r e g i o n . D. Development o f the P r o b a b i l i t y M a t r i c e s The i n f o r m a t i o n c o n t a i n e d i n g r a p h i c a l form ( F i g u r e s 5 t o 9) has to be t r a n s f o r m e d i n t o d i s c r e t e numbers i n o r d e r to be i n a u s e a b l e form f o r the computer program. L o o k i n g a t F i g u r e 5 i t was d e c i d e d t o choose 16 c l a s s e s f o r the escapement and 15 c l a s s e s f o r the r e s u l t i n g female spawners. We t h e r e f o r e have to determine the p r o b a b i l i t y d i s t r i b u t i o n s a t the 20,000 (40,000) 620,000 l i n e s . ( T h i s a b b r e v i a t e d w r i t i n g means s t a r t i n g from the 20,000 l i n e we go i n i n t e r v a l s t e p s of 40,000 u n t i l an escapement v a l u e of 620,000). On the female spawner a x i s we have 15 c l a s s e s w i t h an i n t e r v a l l e n g t h o f 20,000 spawners. To determine the p r o b a b i l i t y t h a t a normal random v a r i a b l e l i e s i n any i n t e r v a l , the i n t e g r a l o f p x ( X ) o v e r the i n t e r - v a l i s r e q u i r e d . I n t e r v a l l e n g t h i s 20,000 spawners. To demonstrate the f o r e g o i n g an escapement f i g u r e o f 420,000 i s chosen. The p r o b a b i l i t y o f h a v i n g spawners i n the 160,000 to 180,000 range i s 0.376, between 180,000 and 200,000 i s 0.591, and between 200,000 and 220,000 i s 0.033. The proba- b i l i t i e s f o r a l l o t h e r spawner c l a s s e s a r e z e r o . 44 T h i s i s done f o r a l l o t h e r s e t escapement l e v e l s and the proba- b i l i t i e s a r e w r i t t e n i n m a t r i x form. We thus a r r i v e a t a m a t r i x o f 16 x 15 elements. The i n t e g r a l over the normal d i s t r i b u t i o n w hich i s g e o m e t r i c a l l y the a r e a under the c u r v e i s 1.0. By u s i n g two s t a n d a r d d e v i a t i o n s f o r our upper and lower c u r v e s we have c u t o f f the t a i l s and t h e r e f o r e have t o n o r m a l i z e the c a l c u l a t e d p r o b a b i l i t i e s so t h a t they add up t o 1.0. In the next s t e p the spawners a r e r e p r e s e n t e d on the x - a x i s . To a v o i d i n t e g r a t i o n o f a two-dimensional d i s t r i b u t i o n f u n c t i o n (remember t h a t we had a normal d i s t r i b u t i o n p a r a l l e l t o the "spawner" a x i s and now have a normal d i s t r i b u t i o n p a r a l l e l t o the "eggs d e p o s i t e d " a x i s as w e l l ) the mean v a l u e o f each spawner c l a s s i s taken as t h e new i n t e g r a t i o n l i n e . The l o s s i n p r e c i s i o n by u s i n g t h i s p rocedure i s c o n s i d e r e d minor compared t o the f a c t t h a t a normal d i s t r i b u t i o n f u n c t i o n w i t h two s t a n d a r d d e v i a t i o n s f o r the c o n f i d e n c e l i m i t s had been assumed w i t h o u t any a n a l y s i s o f the dat a . To c o n t i n u e our a l g o r i t h m we now a r e i n t e r e s t e d t o know how many eggs w i t h which p r o b a b i l i t y w i l l r e s u l t from 170,000 (= 3-60,000 + 180,000^ spawners, how many from 190,000 and 210,000. These p r o b a b i l i t i e s as w e l l as f o r o t h e r spawner v a l u e s a r e w r i t t e n down i n form o f a second proba- b i l i t y m a t r i x . To combine t h e two l i f e s tages one c o u l d ask d i r e c t l y how many eggs w i l l r e s u l t from a g i v e n escapement v a l u e . M a t h e m a t i c a l l y s p e a k i n g , t h i s means m u l t i p l i c a t i o n o f the two p r o b a b i l i t y m a t r i c e s . Each element C-y i n t h i s p r o d u c t m a t r i x i s c a l c u l a t e d c o r r e s p o n d i n g t o n C. . = E a., b, . i j k = 1 i k k j where C^j i s the s c a l a r p r o d u c t o f the i t n r o w v e c t o r o f A and the j t n column v e c t o r o f B. Thus, m u l t i p l i c a t i o n o f a (16 x 15) m a t r i x w i t h a 45 (15 x 16) m a t r i x w i l l y i e l d a (16 x 16) m a t r i x . I n the next s t e p t h i s p r o d u c t m a t r i x i s m u l t i p l i e d by a m a t r i x d e s c r i b i n g the eggs t o f r y s t a g e . A f t e r f o u r m a t r i x m u l t i p l i c a t i o n s we a r r i v e a t a m a t r i x which c o n t a i n s the p r o b a b i l i t i e s r e l a t i n g a g i v e n escapement to v a r i o u s r e t u r n c l a s s e s . ( I n Appendix 2 a flow c h a r t of the computer program i s given.) A l l t h e s e p r o b a b i l i t i e s a r e now m u l t i p l i e d w i t h the mean v a l u e o f each r e t u r n c l a s s and thus an e x p e c t e d r e t u r n v a l u e i s c o n s t r u c t e d c o r r e s p o n d i n g to e q u a t i o n ( A ) . F i g u r e 10 shows the p l o t of t h i s expected r e t u r n c u r v e and the c o n f i - dence l i m i t s a r e g i v e n as w e l l . E. C o n e l u s i o n s T h i s new p r o b a b i l i t y d i s t r i b u t i o n does not f o l l o w any known mathe- m a t i c a l d i s t r i b u t i o n f u n c t i o n . I n the case o f a l o g n o r m a l l y d i s t r i b u t e d v a r i a b l e a l o g n o r m a l d i s t r i b u t i o n s h o u l d r e s u l t a g a i n a f t e r n m u l t i p l i c a - t i o n s t e p s ( t h e d i s t r i b u t i o n o f a p r o d u c t o f lognormals i s l o g n o r m a l a g a i n ( 7 ) ) . I n o r d e r t o v e r i f y a lognormal d i s t r i b u t i o n g o v e r n i n g each l i f e s t a g e t h e parameters f o r t h i s p r o b a b i l i t y d i s t r i b u t i o n f u n c t i o n would have to be e s t i m a t e d u s i n g the a v a i l a b l e d a t a . T h i s i s the o n l y way to judge the v a l i d i t y o f the proposed model. In F i g u r e 10 t h e " r e p l a c e m e n t " l i n e has been i n c l u d e d . T h i s i s the number o f spawners n e c e s s a r y t o m a i n t a i n the s t o c k a t i t s e x i s t i n g l e v e l . I f the r e t u r n i s lower o r e q u a l to the replacement v a l u e no c a t c h can be p e r m i t t e d . The maximum average c a t c h i s c a l c u l a t e d as t h e d i f f e r e n c e be- tween the e x p e c t e d r e t u r n c u r v e and the replacement l i n e . I n C h a p t e r VI a methodology w i l l be d e v e l o p e d whereby the model i s used t o s t u d y the e f f e c t s o f p o t e n t i a l l y i n c r e a s e d m o r t a l i t y due t o poor water q u a l i t y c o n d i t i o n s on the s t o c k s i z e . F i r s t , however, a r e v i e w of FIG. 10 l i t e r a t u r e on the e f f e c t s of p o l l u t i o n on salmonoid f i s h i s i n s e r t e d give the reader an idea of the complex nature of the problem. 48 CHAPTER V THE POLLUTION EFFECTS ON SALMON HOW MUCH DO WE KNOW? -- A REVIEW A. I n t r o d u c t i o n From studies undertaken by various agencies we know that m a t e r i a l s are discharged to the Fraser R i v e r which can be t o x i c to some aquatic organisms at c e r t a i n c o n c e n t r a t i o n l e v e l s . In order to p r e d i c t p o t e n t i a l damage to salmon i n the future we have to i d e n t i f y c r i t i c a l p o l l u t a n t s , study how they a f f e c t those species of the ecosystem which support the salmon, and a l s o what d i r e c t e f f e c t s they have on the f i s h . Since there i s c u r r e n t l y a great deal of i n t e r e s t i n the fu t u r e development of the Lower Mainland i n B r i t i s h Columbia, i t appears that knowledge about the behaviour of a salmon stock exposed to v a r y i n g and increased p o l l u t i o n l e v e l s should be of importance to various d e c i s i o n making groups. In f i s h e r y l a b o r a t o r i e s around the world t e s t s w i t h many p o l l u t a n t s and various species of f i s h i n d i f f e r e n t l i f e stages have been undertaken during the past 20 years. In t h i s s e c t i o n some of the studies which r e l a t e to salmon and i t s food organisms are reviewed. These show that i t i s not p o s s i b l e to develop a simple model which describes the t o x i c and s u b l e t h a l e f f e c t s of a l l the various p o l l u t a n t s on salmon. In order to study p o s s i b l e changes i n the po p u l a t i o n of a sockeye salmon stock, r e s u l t i n g from p o l l u - t i o n , given the present l e v e l of knowledge, some rough approximations must be made. 49 B. C r i t i c a l P o l l u t a n t s i n the Salmon Food Chain E f f l u e n t s from i n d u s t r i a l , domestic, and storm sewers c o n t a i n many chemicals which can be t o x i c once they reach a c e r t a i n c o n c e n t r a t i o n l e v e l i n the aquatic environment or i n the t i s s u e of an organism. However, the b i o l o g i s t i s not j u s t i n t e r e s t e d i n the p o l l u t a n t s at l e v e l s of concentra- t i o n s which would be l e t h a l to f i s h w i t h i n hours. This type of p o l l u t i o n e f f e c t i s v i s i b l e , and the p u b l i c would c e r t a i n l y be very upset by such i n c i d e n t s and demand an i n v e s t i g a t i o n . S c i e n t i s t s are o f t e n more concerned about chronic or s u b l e t h a l c o n c e n t r a t i o n l e v e l s where i t i s o f t e n d i f f i c u l t to r e l a t e cause and e f f e c t . These s u b l e t h a l t o x i c concentrations impose added st r e s s e s on an organism which reduce the l i k e l i h o o d that i t w i l l s u r v i v e i n a competitive environment. The weakened f i s h w i l l be more prone to predation or disease and w i l l a l s o not be able to compete as e f f e c t i v e l y f o r a l i m i t e d food supply. Important p o l l u t a n t s which have been s t u d i e d most f r e q u e n t l y are l i s t e d i n groups and discussed below. 1. Heavy Metals The most t o x i c metals to aquatic organisms are mercury, s i l v e r , and copper followed by cadmium, z i n c , lead, chromium, n i c k e l , and c o b a l t . This order of t o x i c i t y v a r i e s somewhat f o r d i f f e r e n t species and i t depends on the s i z e of the organism, i t s l i f e - s t a g e , i t s absorption, e x c r e t i o n , storage, and r e g u l a t o r y mechanisms (10). Heavy metals p r e c i p i t a t e out of the water a f t e r exceeding t h e i r s o l u b i l i t y product or are adsorbed to sediment p a r t i c l e s . Benthic organisms which l i v e at the bottom of the r i v e r and i t s estuary t h e r e f o r e have o f t e n very h i g h concentrations accumu- l a t e d i n t h e i r body t i s s u e . In Table 1 the f a c t o r s i n f l u e n c i n g the t o x i c i t y of heavy metals to aquatic organisms are summarized. 50 TABLE 1 Factors I n f l u e n c i n g the T o x i c i t y of Heavy Metals to Aquatic Organisms Form of metal i n water s o l u b l e p a r t i c u l a t e { ion complex c h e l a t e compound p r e c i p i t a t e adsorbed Presence of other metals or poisons a n t a g o n i s t i c e f f e c t s a d d i t i v e e f f e c t s s y n e r g i s t i c e f f e c t s Factors i n f l u e n c i n g physiology of organism and p o s s i b l y form of metal i n water f s a l i n i t y temperature d i s s o l v e d oxygen PH hardness p o t h e r p o l l u t a n t s , e.g. hydrocarbons, phenols C o n d i t i o n of the organism P e s t i c i d e s s stage i n l i f e - h i s t o r y changes i n l i f e - c y c l e s i z e of organism a c t i v i t y of organism I. a c c l i m a t i z a t i o n to metals Depending on the a p p l i c a t i o n we d i f f e r e n t i a t e between i n s e c t i c i d e s , h e r b i c i d e s , and f u n g i c i d e s . P e s t i c i d e s are used i n a g r i c u l t u r e , h o r t i c u l - ture, and the v e t e r i n a r y and medical f i e l d . Many of them end up i n our r i v e r s and u l t i m a t e l y i n the sea. As p e s t i c i d e s are very i n s o l u b l e a water q u a l i t y a n a l y s i s w i l l o f t e n not t e l l us i f we face a contamination problem. Sediment and f i s h t i s s u e analyses have to be done a d d i t i o n a l l y . Only a l i m i t e d number of a n a l y t i c a l techniques i s a v a i l a b l e f o r determin- ing residues at the low l e v e l s o c c u r r i n g i n the environment. Acute t o x i c i t y g e n e r a l l y r e s u l t s only from high shock loads to the r e c e i v i n g water a f t e r a c c i d e n t a l s p i l l a g e s or c a r e l e s s d i s p o s a l of surplus concentrates. However, we can a l s o observe some long-term e f f e c t s of c e r t a i n p e s t i c i d e s on the aquatic f l o r a and fauna although these g e n e r a l l y are not accompanied by acute t o x i c i t y . A h e r b i c i d e may destroy the rooted v e g e t a t i o n of a stream or pond, d r a s t i c a l l y changing the environment of small f i s h and many species of i n v e r t e b r a t e s . The s t r u c t u r e of the f i s h p o p u l a t i o n may thus be d i s - turbed, and the i n v e r t e b r a t e fauna which c o n s t i t u t e s the food of many species of f i s h can be s e r i o u s l y reduced. Some i n s e c t i c i d e s are p a r t i c u - l a r l y t o x i c to zooplankton and i n s e c t l a r v a e , and t h e i r d e s t r u c t i o n w i l l r e - duce the food supply of f i s h . Very o f t e n p e s t i c i d e s are more t o x i c to the food of f i s h than to f i s h themselves. I n t e r f e r e n c e w i t h the d i v e r s i t y or abundance of i n v e r t e - brate fauna can have f a r - r e a c h i n g consequences f o r a f i s h population. 3. C h l o r i n e and Chloramines For h y g i e n i c reasons sewage e f f l u e n t i s c h l o r i n a t e d p r i o r to d i s - charge. The r e s i d u a l c h l o r i n e may undergo chemical r e a c t i o n s w i t h some of the organic m a t e r i a l . One c l a s s of these r e a c t i o n products, the c h l o r a - mines, are extremely t o x i c f o r aquatic organisms (53). 4. Ammonia, phenols, PCB's ( p o l y c h l o r i n a t e d b i p h e n y l s ) and some d e t e r g e n t s have been shown t o x i c t o f i s h o r i t s food organisms (40,58). 5. A low d i s s o l v e d oxygen l e v e l i n the water, h i g h water tempera- t u r e s , extreme pH v a l u e s , h i g h c o n c e n t r a t i o n s o f b a c t e r i a i n the water, e x c e s s i v e d i s s o l v e d s o l i d s c o n c e n t r a t i o n s have been found t o i m p a i r the s u r v i v a l chances of f i s h (1,50). C. E x p e r i m e n t a l E v i d e n c e Most o f the f a c t s about the e f f e c t s o f hazardous p o l l u t a n t s on the a q u a t i c environment have been a c q u i r e d from l a b o r a t o r y s t u d i e s . We would l i k e t o have more data from f i e l d o b s e r v a t i o n s s i n c e an i n c r e a s e above the n a t u r a l m o r t a l i t y r a t e would most l i k e l y have a s e r i o u s e f f e c t on the p o p u l a t i o n . However, the c o m p l e x i t y o f the a q u a t i c environment w i t h i t s v a r i e t y o f s p e c i e s , t h e i r i n t e r r e l a t i o n s h i p s , p o p u l a t i o n numbers, s e a s o n a l and a n n u a l changes i n the f l o w and temperature regime o f the r i v e r make such an u n d e r t a k i n g v e r y d i f f i c u l t . C o n s e q u e n t l y , the i n f l u e n c e of some p o l l u t a n t s i n c a u s i n g c h r o n i c t o x i c e f f e c t s w i l l u s u a l l y pass u n r e c o g n i z e d . We have t o e s t a b l i s h the p o s s i b l e r i s k t o f i s h o r t o o t h e r components o f the f r e s h w a t e r community i n d i r e c t l y by r e l a t i n g measured c o n c e n t r a t i o n s i n the water, sediment or o rganism t o e x p e r i m e n t a l o b s e r v a t i o n s i n the l a b o r a - t o r y . B i o a s s a y s to study a c u t e t o x i c i t y caused by one o r more c h e m i c a l s a r e the most f r e q u e n t l y used t e s t s . I n t h e s e t e s t s a d u l t or j u v e n i l e f i s h a r e exposed f o r time p e r i o d s v a r y i n g from 24 t o 96 hours to d i f f e r e n t con- c e n t r a t i o n s o f the p o l l u t a n t under i n v e s t i g a t i o n and the number of f i s h k i l l e d d u r i n g the experiment i s r e c o r d e d . Most o f the a v a i l a b l e a c u t e 53 t o x i c i t y d a t a a r e r e p o r t e d as median l e t h a l c o n c e n t r a t i o n (LC50) which s i g n i f i e s the c o n c e n t r a t i o n a t which 50% o f the t e s t organisms s u r v i v e w i t h i n a s p e c i f i e d time span, u s u a l l y i n 96 h o u r s . By u s i n g a c u t e t o x i c i t y t e s t s i t has been shown (2,21,38) t h a t changes i n the c h e m i c a l and p h y s i c a l c h a r a c t e r i s t i c s o f the water have a marked e f f e c t on the t o x i c i t y o f a p o i s o n t o f i s h . Heavy metals a r e more t o x i c i n s o f t water t h a n i n h a r d , the t o x i c i t y o f ammonia v a r i e s w i t h the pH v a l u e and the temperature o f the water, and low l e v e l s o f d i s s o l v e d oxygen d e c r e a s e the r e s i s t a n c e o f f i s h t o p o l l u - t a n t s . In the case o f copper, f o r example, i t has been h y p o t h e s i z e d t h a t o n l y the i o n i c f r a c t i o n o f the t o t a l copper i s t o x i c . O r g a n i c compounds have been shown t o c h e l a t e d i s s o l v e d copper. The complexing agents can be humic a c i d s , amino a c i d s , o r p o l y p e p t i d e s (70). Thus, when we t a l k about the t o x i c i t y o f copper t o a q u a t i c organisms we have t o determine the f r a c - t i o n which i s b i o l o g i c a l l y a v a i l a b l e ( 3 7 ) . D i f f e r e n t s p e c i e s o f f i s h v a r y i n t h e i r r e s i s t a n c e t o p o i s o n s ; i n g e n e r a l , c o a r s e f i s h a r e more r e s i s t a n t than salmonid J s p e c i e s . T h e r e f o r e , many t e s t s a r e b e i n g conducted u s i n g t r o u t o r salmon as t e s t f i s h . A l s o i m p ortant i s the s e n s i t i v i t y o f the v a r i o u s l i f e s t a g e s o f organisms. Many organisms a r e most s e n s i t i v e i n the l a r v a l , nymphal, m o l t i n g , o r f r y s t a g e . E v a l u a t i o n o f t o x i c i t y t o a s p e c i e s , t h e r e f o r e , cannot s o l e l y be based on the a d u l t organism. Some p e s t i c i d e s have been shown(26) t o a f f e c t r e p r o d u c - t i o n ( f a i l u r e o f eggs t o h a t c h ) . H i g h c o n c e n t r a t i o n s o f heavy metals i n the water have a d v e r s e e f f e c t s on the eggs d e p o s i t e d on the spawning grounds. Another problem a r e a i s the s t u d y o f e f f e c t s which m i x t u r e s o f p o i s o n s have on the organism. As p o l l u t e d r i v e r s u s u a l l y c o n t a i n more than one p o i s o n the c o n t r i b u t i o n o f each one t o the t o t a l t o x i c i t y needs t o be assessed. We have to d i f f e r e n t i a t e between s y n e r g i s t i c , a n t a g o n i s t i c , and a d d i t i v e e f f e c t s . By s y n e r g i s t i c a c t i o n the combined i n f l u e n c e of s e v e r a l substances r e s u l t s i n greater t o x i c i t y to the organism than the sum of the i n d i v i d u a l e f f e c t s taken independently. Therefore, l e t h a l t h r e s h o l d con- c e n t r a t i o n s determined f o r various p o l l u t a n t s s e p a r a t e l y i n l a b o r a t o r y t e s t s cannot simply be t r a n s f e r r e d to the f i e l d where a wide v a r i e t y of substances might i n t e r a c t w i t h each other and r e s u l t i n a much higher t o x i - c i t y . On the other hand, c e r t a i n combinations of compounds act to repress the d e l e t e r i o u s e f f e c t s of one another ( a n t a g o n i s t i c ) . I t has been found that the r a t i o i n which the p o l l u t a n t s are present i s q u i t e important (59). While the study of l e t h a l e f f e c t s of poisons on f i s h i s f a i r l y straightforward'?:/ experiments to study s u b l e t h a l e f f e c t s are much more d i f f i c u l t to design. S u b l e t h a l e f f e c t s i n c l u d e changes i n h i s t o l o g y , physiology, growth, swimming a b i l i t y , r e s p i r a t i o n r a t e s , behaviour, and reproduction. There are three major types of t e s t s to study s u b l e t h a l e f f e c t s : the p h y s i o l o g i c a l t e s t , the behaviour t e s t , and the l i f e - c y c l e t e s t . A p h y s i o l o g i c a l t e s t can c o n s i s t , f o r example, i n the measurement of increased u r i n e production by the f i s h as a response to i n c r e a s i n g ammonia conc e n t r a t i o n (38), or the measurement of the change i n the oxygen consumption r a t e , or observation of an excessive mucus sec r e t i o n s on the g i l l s (13,40). The l i m i t a t i o n s of t h i s type of approach are that the p h y s i o l o g i c a l response should be both e s s e n t i a l to the w e l l - b e i n g of the f i s h as well-.,as being the one most s e n s i t i v e to the poison under t e s t . Hatch (reported i n 38) devised a g r a p h i c a l r e l a t i o n s h i p between an increase i n p h y s i o l o g i c a l s t r e s s and the degree of impairment of b o d i l y f u n c t i o n (Figure 11). 55 normal adjustment compensation breakdown failure physiological impairment FIG. II A P O S S I B L E RELATION B E T W E E N PHYSIOLOGICAL IMPAIRMENT FOLLOWING INCREASING E X P O S U R E TO POLLUTANTS AND THE CONSEQUENT DISABIL ITY OF THE F I S H ( A F T E R H A T C H ) . 56 In behaviour tests the threshold concentration is determined at which fish, given a choice between contaminated and clean water, is able to avoid the polluted region. Usually there is a clear interface between the two conditions and no external stimuli. This, of course, is not typical for natural waters where a clear-cut line between polluted and unpolluted areas does not necessarily exist. Other behaviour patterns, such as migrating or t e r r i t o r i a l behaviour, may have an overriding effect. For example, i t was found that salmon on their upstream migration were turned back only when the combined levels of a copper/zinc concentration were 20 times higher than the ones found in a laboratory test where non-spawning salmon had been used as a test fish (60). Another test to find out the behaviour of fish to a reduction in the dissolved oxygen level is reported in (38). Here the number of fish are counted leaving an area which becomes suddenly depressed in dissolved oxygen. Lethargic behaviour of juvenile sockeye is reported by Servizi (40) when the fish were exposed to detergent levels which were nontoxic to them. In a life-cycle test fish are exposed to constant levels of poisons for periods up to 11 months to determine the concentration at which the growth rate and breeding success is similar to that of control fish. The drawbacks of this test are: (a) It is time consuming and extensive testing f a c i l i t i e s are required. (b) Fish are fed with a r t i f i c i a l food and treated with antibiotics to prevent disease. (c) Fish are exposed to constant levels of poison, whereas in their natural environment the concentration normally fluctuates. 57 Summarizing we can say: Acute t o x i c i t y t e s t s can be used to measure the e f f e c t of chemical and p h y s i c a l v a r i a b l e s on the t o x i c i t y of poisons and on the r e s i s t a n c e of f i s h to them. In order to use data obtained from short-term l a b o r a t o r y experiments to set up water q u a l i t y c r i t e r i a to guarantee a healthy environ- ment f o r f i s h , a p p l i c a t i o n f a c t o r s should be used. An a p p l i c a t i o n f a c t o r converts l e t h a l concentrations found i n a short-term t e s t to a concentra- t i o n which i s harmless under c o n d i t i o n s of long-term exposure (51). Results from s u b l e t h a l t e s t s can give an i n s i g h t i n t o the mechanism of t o x i c a c t i o n and experiments should be designed to show the l e v e l of no adverse e f f e c t . F i e l d observations can provide v a l u a b l e information on the l e v e l s of p o l l u - tants at which f i s h e r i e s are unaffected and, i n some cases, the graded e f f e c t of increased p o l l u t i o n on the d e t e r i o r a t i o n of a f i s h population. I t can be s a i d that there i s no such t h i n g as the c o n c e n t r a t i o n of a poison above which f i s h w i l l be absent and below which they w i l l f l o u r i s h . Rather, there i s a range of i n c r e a s i n g concentrations w i t h i n which f i s h - e r i e s w i l l l i k e l y show a progressive d e t e r i o r a t i o n , e i t h e r i n q u a l i t y or i n numbers or both. The next d e s i r a b l e step i s to process the amount of info r m a t i o n a v a i l a b l e from a l l these t e s t s and observations i n a way which i s comprehen- s i b l e to the d e c i s i o n maker who might not be an expert i n f i s h e r i e s , t o x i - cology, or aquatic chemistry. In order to simulate p o l l u t i o n e f f e c t s on a salmon stock and to make a f o r e c a s t of the probable numbers of r e t u r n i n g a d u l t s when the stock has been exposed to d i f f e r e n t p o l l u t i o n l e v e l s , a' common " y a r d s t i c k " f o r a l l the various p o l l u t a n t s i s needed. 58 CHAPTER VI SIMULATION OF A SALMON STOCK UNDER VARIED LEVELS OF POLLUTION A. I n t r o d u c t i o n In the previous chapter some of the many p o l l u t a n t s which can have adverse e f f e c t s on salmon at c e r t a i n c o n c e n t r a t i o n l e v e l s were discussed. I t was pointed out how d i f f i c u l t i t i s to describe the s y n e r g i s t i c e f f e c t of the multitude of p o l l u t a n t s encountered i n the waste discharges from an urban i n d u s t r i a l area. S u b l e t h a l e f f e c t s are very i n s i d i o u s i n nature but they do not r e s u l t i n an immediate increase i n m o r t a l i t y . Their cumulative e f f e c t , however, can be seen i n a lower o v e r a l l r e t u r n r a t e . A weakened organism w i l l be more prone to p r e d a t i o n i n the ocean, i t s l i f e expectancy may be shortened, and i t s f e c u n d i t y may be reduced. In the Fraser R i v e r i t s e l f there have been no documented f i s h k i l l s due to acute t o x i c i t y c o n d i t i o n s i n the water. Problems are more l i k e l y w i t h s u b l e t h a l e f f e c t s . Water q u a l i t y w i l l vary w i t h place and time because of changes i n stream flow, t i d a l a c t i o n , seasonal d i f f e r e n c e s i n temperature, and f l u c t u a t i n g waste discharges, both i n volume and strength. Long-term averages, f o r instance, do not r e f l e c t the short-term s t r e s s that may be imposed on an organism by a shock load of a harmful m a t e r i a l . The best way to monitor water q u a l i t y over time i s to use an organism which depends on good water q u a l i t y , f o r example, salmon. The organism i n t e g r a t e s i t s response through time and r e a c t s to a l l s y n e r g i s t i c and a n t a g o n i s t i c e f f e c t s of combined p o l l u t a n t s or s t r e s s e s . This being recognized^,in s i t u bioassays at points i n the r i v e r where c r i t i c a l water q u a l i t y c o n d i t i o n s are expected are p r e s e n t l y the most popular method to r e l a t e measured 59 p h y s i c a l and chemical parameters to the s u r v i v a l or p h y s i o l o g i c a l w e l l - being of f i s h . B. F i s h Tests i n the Fraser R i v e r and the Co a s t a l Zone Every time the P o l l u t i o n C o n t r o l Board r e c e i v e s an a p p l i c a t i o n f o r a permit to discharge waste water to the Fraser R i v e r , other government agencies i n c l u d i n g the f e d e r a l F i s h e r i e s S e r v i c e and Environmental Protec- t i o n S e r v i c e , the I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission (IPSFC), and various p u b l i c i n t e r e s t groups are asked to comment. In cases where these wastes might c o n t a i n substances which are b e l i e v e d to be t o x i c to salmon, IPSFC u s u a l l y conducts bioassay t e s t s i n i t s l a b o r a t o r y . Such s t u d i e s , f o r example, i n v e s t i g a t e d l e t h a l and s u b l e t h a l e f f e c t s on j u v e n i l e sockeye and pink salmon due to d e - i n k i n g wastes from a proposed new paper m i l l u s i n g waste newspaper as i t s major raw m a t e r i a l (40). The f i s h were exposed to a s e r i e s of d i l u t i o n s . Results i n d i c a t e d that these d e - i n k i n g wastes were even more t o x i c than wastes from k r a f t pulp m i l l s . Furthermore, i t was found that the detergents i n these d e - i n k i n g wastes caused le t h a r g y , excessive mucous s e c r e t i o n on the g i l l s , and depressed oxygen consumption of the salmon f r y at concentrations l e s s than the l e t h a l l e v e l . At major sewage o u t f a l l s , f o r example near the three m u n i c i p a l treatment p l a n t s which discharge to the Fraser, i n s i t u bioassay t e s t s have been done r e c e n t l y on an annual basis to assess acute t o x i c i t y . Researchers from the F i s h e r i e s S e r v i c e of Environment Canada keep coho f i n g e r l i n g salmon i n cages near the Annacis I s l a n d sewage o u t f a l l , every year two weeks p r i o r to the beginning of the f r e s h e t (31). IPSFC has undertaken s e v e r a l bioassay studies to assess acute t o x i - c i t y of municipal sewage to f i n g e r l i n g sockeye and pink salmon (39,53). 60 It was demonstrated that effluent from a primary municipal sewage treatment plant is toxic to fish, especially when chlorinated. Dechlorination was considered necessary to eliminate this toxicity resulting from several newly formed chlorinated organic compounds. Recently, more attention has been given to the analysis of muscle tissue from fish and other commercially valuable marine organisms. Analyses are made for heavy metals, particularly mercury and cadmium, PCB's and pesticides in tiss,ue samples. The high content of mercury found in the tissue of crabs was cause for the closure of the commercial fishery in Howe Sound (66). Later on this decision was revised so that migratory species, such as salmon, could be caught. Our knowledge about the accumulation of toxic materials through the food chain is very poor. At present an international research team at Saanich Inlet (off the coast of Vancouver Island) are trying to evaluate the pathways of some heavy metals, such as copper, mercury, cadmium, and lead through the ecosystem. The experiments are done in huge plastic bags which are open at the top so that the exchange with the atmosphere can continue. Efforts are made to have the marine environment undisturbed as much as possible. Concentrations of the heavy metal added to the water in this enclosed ecosystem were sometimes as high as 250 times natural background level. Samples are taken from the water, the detritus, the phyto- and the zooplankton as well as cultured chum fingerling salmon (only in some experiments) to determine the distribution of the metal. In another study possible shifts in the ecosystem due to increased levels of hydrocarbons, such as refinery o i l and fuel, are investigated. In the case of phytoplankton i t was observed that a shift from big cells to small cells occurred (61). This finding is-of great importance as larger zooplankters, which form the main d i e t f o r f i s h , do not feed on these s m a l l phytoplankton c e l l s . Could t h i s mean a d i m i n i s h i n g food supply f o r f i s h as a r e s u l t of i n c r e a s i n g p o l l u t i o n i n the ocean? The stu d i e s are being continued and more data w i l l e i t h e r confirm or disprove t h i s hypo- thes i s . A l l these s t u d i e s i n d i c a t e how much research work s t i l l has to be done i n order to get good data on which f u t u r e hypotheses and models can be based. C. E f f e c t s of Various M o r t a l i t y Rates on the S i z e of a Sockeye Salmon Stock As has been pointed out i n the d i s c u s s i o n of previous s e c t i o n s , present understanding i s not s u f f i c i e n t to r e l a t e p o l l u t i o n l e v e l s i n the water to p o s s i b l e changes i n the stock/recruitment r e l a t i o n s h i p . We do not know what e f f e c t s some waste chemicals have on the upstream m i g r a t i n g spawners. Do they have a masking e f f e c t , thus i n t e r f e r i n g w i t h the salmon's sensing system which enables the f i s h to f i n d i t s way.back to i t s homestream? ( I t i s b e l i e v e d that salmon are able to recognize the chemical' c h a r a c t e r i s t i c s of the water and sediment and f i n d t h e i r way back.) We do not know i f the s u r v i v a l chances of j u v e n i l e salmon migrating downstream and having to pass p o l l u t e d water are reduced due to a d d i t i o n a l s t r e s s on the organism. What are the e f f e c t s of increased p o l l u t i o n l e v e l s on other organisms i n the estuary which are a food source f o r the j u v e n i l e salmon? I t i s known that young salmon feed on r i v e r i n v e r t e b r a t e s during t h i s journey downstream. Some salmon species (not so much sockeye j u v e n i l e s ) stay up to three months i n the estuary and feed there (16,43). Could there be a de- crease i n r e t u r n i n g a d u l t s due to such changes of the estuary environment? 62 For the f o l l o w i n g s i m u l a t i o n studies i t was pos t u l a t e d that i n the fu t u r e , as i s the case now, acute t o x i c i t y c o n d i t i o n s w i l l not be the normal case but r a t h e r be l i m i t e d to a c c i d e n t a l s p i l l s that can cause te m p o r a r i l y unfavourable water q u a l i t y c o n d i t i o n s . More important i s the water q u a l i t y g e n e r a l l y encountered which can be c h a r a c t e r i z e d by i t s BOD, temperature, d i s s o l v e d and suspended s o l i d s , ammonia, et c . There i s no doubt that i n c r e a s i n g waste discharges to the Fraser R i v e r w i l l cause a d e t e r i o r a t i o n of water q u a l i t y i f a t the same time e f f o r t s are not made to reduce the loadings of p o l l u t a n t s through a p p r o p r i a t e treatment processes. Poor water q u a l i t y c o n d i t i o n s are assumed to a f f e c t both the up- r i v e r m i g r a t i n g a d u l t spawners and the young smolts m i g r a t i n g to the ocean and thus r e s u l t i n lower s u r v i v a l r a t e s during these two l i f e stages. The only parameter used to express the u n d e r l y i n g s u b l e t h a l e f f e c t s was increase i n n a t u r a l m o r t a l i t y r a t e (or decrease i n s u r v i v a l r a t e ) . L a c k i n g any inf o r m a t i o n from data s e v e r a l a l t e r n a t i v e values f o r the r e d u c t i o n i n sur- v i v a l r a t e during these two l i f e stages were t r i e d . The e f f e c t s of various m o r t a l i t y r a t e s of up to 507, on the stock s i z e were c a l c u l a t e d u s i n g the computer model which has been described i n d e t a i l i n Chapter IV. I n c r e a s i n g m o r t a l i t y r a t e s r e s u l t i n lower expected r e t u r n values. The r e s u l t s are shown i n Figures 12 to 17.. I t w i l l be noted that at a m o r t a l i t y r a t e of 307o there e x i s t s a 57, p r o b a b i l i t y that the stock s i z e reaches such a low l e v e l from that i t may not recover again. The a l l o w a b l e catch i s the d i f f e r e n c e between the expected r e t u r n and the necessary escapement to continue the c y c l e . This d i f f e r e n c e be- comes f u r t h e r depressed w i t h i n c r e a s i n g m o r t a l i t y r a t e . As a next step the e q u i l i b r i u m l e v e l s corresponding to d i f f e r e n t m o r t a l i t y rates were computed. This e q u i l i b r i u m l e v e l i s the salmon run 100 .200 300 400 500 600 Escapement in thousands FIG. 12 EXPECTED RETURN [MORTALITY RATE 5%.] 100 200 300 400 500 600 Escapement in thousands ON FIG. 13 EXPECTED RETURN [MORTALITY RATE 10%.] return I Q 0 200 300 400 500 600 Escapement in thousands FIG. 14 EXPECTED RETURN [MORTALITY RATE 20%.] 100 200 300 400 500 600 Escapement in thousands FIG. 15 EXPECTED R ETUR N [MORTALITY RATE 30%.] 3.0 100 200 300 400 500 600 Escapement in thousands ON FIG. 16 EXPECTED RETURN [MORTALITY RATE 40%.] 3 . 0 100 2 00 300 400 500 600 Escapement in thousands FIG. 17 EXPECTED RETURN [MORTALITY RATE 50%.] 69 s u s t a i n a b l e under water q u a l i t y c o n d i t i o n s which would cause a c e r t a i n m o r t a l i t y to passing salmon. In order to c a l c u l a t e t h i s e q u i l i b r i u m i t i s necessary to assume a r e l a t i o n s h i p between r e t u r n i n g a d u l t s and the chosen escapement. This l a s t r e l a t i o n s h i p closes the salmon l i f e c y c l e . Figure 18 proposes such a mangement scheme f o r h a r v e s t i n g salmon. In the lower r e t u r n ranges the manager w i l l t r y to b u i l d the stock up by a l l o w i n g up to 507o escapement whereas f o r bigger r e t u r n values a higher percentage can be a l l o t t e d to the fishermen. (This s t r a t e g y should not be confused w i t h the present s t r a t e g y used to manage Fraser salmon and maintain i t s dominant, subdominant, o f f - y e a r p a t t e r n . I t was r a t h e r devised to counteract the e f f e c t of reduced reproduction due to p o l l u t i o n problems and to r e b u i l d the stock s i z e . ) The i n f o r m a t i o n from t h i s set of curves i s brought again i n t o matrix form. Now the computer model can c a l c u l a t e c o n t i n u o u s l y as many salmon l i f e c y c l e s as are necessary to s t a b i l i z e r e t u r n values a t an equi- l i b r i u m f o r each s p e c i f i e d m o r t a l i t y r a t e . This e q u i l i b r i u m i n d i c a t e s the l e v e l to which one can s u s t a i n the stock w i t h the proposed management scheme and under the given m o r t a l i t y r a t e . Results of these si m u l a t i o n s were used to draw the curves i n Figure ,19. I t can be n o t i c e d again that at a m o r t a l i t y r a t e of 307 o the stock s i z e reaches a c r i t i c a l l e v e l . The c a l c u l a t i o n s done i n t h i s s i m u l a t i o n study can be regarded as a f i r s t attempt to describe the interdependence of p o l l u t i o n and the s i z e of a salmon stock. M o r t a l i t y r a t e was the only parameter used to demon- s t r a t e the change i n the stock/recruitment r e l a t i o n s h i p due to poor water q u a l i t y c o n d i t i o n s . Constant reductions i n s u r v i v a l had been assumed i n the two l i f e stages under c o n s i d e r a t i o n . I f the nature of changes due to su b l e t h a l e f f e c t s were b e t t e r known a new set of curves could be constructed 600 Chosen Matri) [l5 x 16] LO 2.0 Returning adults in millions 3.0 FIG. 18 POSSIBLE MANAGEMENT SCHEME TO HARVEST SALMON FIG. 19 SUSTAINABLE RUN WITH ESCAPEMENT STRATEGY OF FIG. 18 [EQUILIBRIUM L E V E L ] •. • . 72 and used as input to the model. Another hypothesis i s that p o l l u t i o n might cause a s h i f t i n the d i s t r i b u t i o n f u n c t i o n between confidence l i m i t s l e a d - i n g to a more accentuated skewness. For example, i t i s known that r a i s e d water temperature has an e f f e c t on prespawning m o r t a l i t y . Figures from such observations could be fed i n t o the model. In the next chapter the p o s s i b i l i t y of c o n s t r u c t i n g a p o l l u t i o n index from a v a r i e t y of water q u a l i t y parameters and r e l a t i n g i t to an increase i n m o r t a l i t y i s d i s - cussed. 73 CHAPTER V I I THE USEFULNESS OF AN INDEX TO FORECAST WATER QUALITY CHANGES AND THEIR EFFECTS ON WATER USE A. Pro and Contra f o r Developing a Water Q u a l i t y Index There i s a growing need to t u r n from management by r e a c t i o n to management by a n t i c i p a t i o n of problems. This a n t i c i p a t o r y approach to management requires techniques f o r f o r e c a s t i n g . We are s t i l l i n a very p r i m i t i v e stage w i t h respect to developing adequate f o r e c a s t i n g models. In order to p r e d i c t future events a thorough a n a l y s i s of the past and the present i s re q u i r e d . One way to aggregate and to summarize the a v a i l a b l e data on a p a r t i c u l a r problem i s to construct an index. Indices are a very e f f e c t i v e way to aggregate and communicate informa t i o n on trends to the policy-makers and the general p u b l i c . They are a device f o r e s t a b l i s h - ing where we are and how we are progressing. For years we have been opera- t i n g w i t h i n d i c e s i n economics and s o c i a l sciences to demonstrate change and trends. Only r e c e n t l y has an i n t e r e s t been taken i n developing environ- mental i n d i c e s (11,65). Un f o r t u n a t e l y , many s c i e n t i s t s have very strong r e s e r v a t i o n s about a numerical indexing procedure. They f e e l that the problem i s f a r too complex to be adequately represented by a s i n g l e value. However, c o l l e c - t i n g an abundance of data on the chemical, p h y s i c a l , and b i o l o g i c a l con- d i t i o n of a r i v e r and r e l a t i n g a l l these data to something such as w e l l - being of f i s h g e n e r a l l y confuses the policy-makers and the general p u b l i c . An index would f a c i l i t a t e communication between the s c i e n t i s t and the non- s c i e n t i f i c community. I t would a l s o help to h i g h l i g h t major trends. By u s i n g an index to describe the c o n d i t i o n of a r i v e r we have to accept some red u c t i o n i n p r e c i s i o n . However, we gain i n our a b i l i t y to communicate. An index can always be backed up by more d e t a i l e d data to a l l o w s p e c i f i c analys i s . One way to construct a p o l l u t i o n index i s described by Nemerov (42). Each value f o r a p o l l u t a n t i s r e l a t e d to a standard value which i s , i n most cases, the p e r m i s s i b l e water q u a l i t y l e v e l . These r e l a t i v e terms are a l l summed up assuming an a d d i t i v e p o l l u t i o n e f f e c t of the s e v e r a l p o l l u t a n t s . This approach i s o f t e n taken to describe the t o t a l t o x i c i t y when s e v e r a l t o x i c m a t e r i a l s (T^, T£, T3, ...) c o e x i s t i n a water body. Their permis- s i b l e l e v e l s (TL^, TL2, TL3, ...) are determined i n bioassay t e s t s . T o t a l t o x i c i t y then equals: T l T 2 T 3 TT = + + + ... TL-L TL 2 TL3 I f t h i s sum exceeds the value of 1.0, the water i n question i s considered t o x i c f o r the s p e c i f i c use. S y n e r g i s t i c or a n t a g o n i s t i c e f f e c t s can be included by m u l t i p l y i n g some components w i t h appropriate weighting f a c t o r s . Another method to construct a water q u a l i t y index r e l a t i n g to the s p e c i f i c water use of f i s h and w i l d l i f e i s described by O'Connor i n h i s d i s s e r t a t i o n (45). This seems to be a promising step i n the r i g h t d i r e c - t i o n and w i l l t h e r e f o r e be presented i n the context of t h i s paper. B. C o n s t r u c t i o n of a Water Q u a l i t y Index f o r F i s h and W i l d l i f e O'Connor based h i s research on a study which had been undertaken by Brown et al_. ( 8). In t h i s study experts were asked to designate para- meters to be included i n an index, to weigh these parameters i n terms of t h e i r r e l a t i v e importance to o v e r a l l water q u a l i t y , and to draw curves i n d i c a t i n g water q u a l i t y as a f u n c t i o n of each parameter on a s c a l e reach- i n g from 0 to 100. The r e s u l t was an a d d i t i v e index of o v e r a l l water q u a l i t y i n v o l v i n g nine, parameters. Many experts p a r t i c i p a t i n g i n t h i s study agreed that i t i s e a s i e r and more meaningful to construct an index f o r a s p e c i f i c water use. Judgments concerning parameter . i n c l u s i o n , weight- ing, and s c a l i n g vary as a f u n c t i o n of the water use. O'Connor th e r e f o r e t r i e d to develop i n h i s d i s s e r t a t i o n v a l i d i n d i c e s f o r very divergent uses of water and determined how much the r e s u l t i n g numbers d i f f e r e d f o r d i f f e r - ent users when he computed the i n d i c e s of s e l e c t e d water samples. One index chosen described the q u a l i t y of a surface body of raw water s u s t a i n - ing a f i s h and w i l d l i f e p opulation. O'Connor defined the problem of developing a water q u a l i t y index as one of ". . . f i n d i n g a s u i t a b l e mathematical f u n c t i o n , i n v o l v i n g an appropriate set of parameters, which assigns to a complex m u l t i - a t t r i b u t e d s t i m u l u s , a surface body of raw water, a number which adequately represents f o r a p a r t i c u l a r d e c i s i o n - maker and w i t h respect to a p a r t i c u l a r c r i t e r i o n , the worth of that s t i m u l u s . " The mathematical f u n c t i o n was assumed to be a d d i t i v e and w r i t t e n i n the form: n W(X.) = £ v. a). (X. .) where: X^ = a n-dimensional stimulus cijj = the value of the q u a l i t y curve f o r parameter l e v e l X^j ( u t i l i t y ) v. = the average importance weight assigned to the j t n dimension. To derive the u t i l i t y f u n c t i o n , s i x experts i n the f i e l d of water q u a l i t y were consulted. A t e s t c o n t a i n i n g over 30 parameters g e n e r a l l y a s s o c i a t e d w i t h water q u a l i t y was presented to them. O'Connor used a modified v e r s i o n of the "Delphi? technique (12) where the p a r t i c i p a n t s are confronted w i t h a s e r i e s of questionnaires. A f t e r each round of ques- t i o n n a i r e s , O'Connor informed the members of t h i s group about t h e i r answers without r e v e a l i n g names of the i n d i v i d u a l s h o l d i n g these opinions. He a l s o evaluated the r e s u l t s and proposed a compromise f o r the next d i s c u s - s i o n round. In the f i r s t q u e stionnaire the experts had to agree upon some c r i t i c a l parameters to be included i n the index. I f too many parameters are used to construct the index, the decision-maker's c a p a c i t i e s break down or perform sub-optimally. The nine parameters decided upon f o r i n c l u s i o n i n t o the f i s h and w i l d l i f e water q u a l i t y index and t h e i r impor- tance weights v'j i n normalized form are given i n Table 2. The q u a l i t y curves y i e l d i n g the a)j f o r the a n a l y s i s are shown i n Figures 20 to 28. These curves are compromise curves proposed by O'Connor a f t e r d i s c u s s i o n and were accepted by the experts. In O'Connor's approach the f u n c t i o n W(X^) i s regarded to be a d d i t i v e i n nature. This only holds i f the parameters measured are i n a reasonable range. For extreme parameter values, the e f f e c t would be the same as w i t h t o x i c substances. They then cannot be traded o f f against other dimensions i n terms of water q u a l i t y . For example, extreme values f o r d i s s o l v e d oxygen c o n c e n t r a t i o n , temperature, pH, ammonia, n i t r a t e s , and phenols have been found to i n d i c a t e water q u a l i t y c o n d i t i o n s which are l e t h a l to f i s h . O'Connor ther e f o r e decided to set the index value to zero i f water q u a l i t y reached zero on any of the nine dimensions. In the presence of t o x i c m a t e r i a l s , such as heavy metals and p e s t i c i d e s , t o lerance values have to be 77 TABLE 2 Parameters and T h e i r Importance Weights f o r C o n s t r u c t i o n o f a Water Q u a l i t y Index f o r F i s h and W i l d l i f e Parameters Importance Weight N o r m a l i z e d Weight D i s s o l v e d oxygen 100 .206 Temperature 82.5 .169 PH 69 .142 Phenols 48 .099 T u r b i d i t y 43 .088 Ammonia 41 .084 D i s s o l v e d s o l i d s 36 .074 N i t r a t e s 36 .074 Phosphates 31 .064 used. I f the c o n c e n t r a t i o n o f any t o x i c a n t i s above i t s c r i t i c a l v a l u e , the water q u a l i t y i s s e t to z e r o . C. F o r e c a s t i n g P o t e n t i a l P o l l u t i o n E f f e c t s How c o u l d such an index be used t o r e l a t e water q u a l i t y i n the F r a s e r R i v e r t o s u b l e t h a l e f f e c t s on salmon? As has been s t a t e d p r e v i o u s l y t h e r e a r e s e v e r a l s u bstances which a r e p o t e n t i a l l y h a r m f u l t o salmon a t c e r t a i n c o n c e n t r a t i o n s . E x t e n s i v e and sometimes t e d i o u s work i s n e c e s s a r y t o determine p r e s e n t l o a d i n g s o f each s i n g l e p o l l u t a n t i n the r i v e r . Some work i n t h i s d i r e c t i o n has been 78 15 30 45 60 75 90 105 120 135 150 165 Dissolved Oxygen (%Saturation ) FIG. 20 WATER QUALITY AS A FUNCTION OF D.O. SATURATION,SUMMER TEMPERATURES . -15 -10 - 5 0 5 10 15 Temperature departure from Ambient ( ° C ) FIG.21 WATER QUALITY AS A FUNCTION OF TEMPERATURE.DEPARTURE FROM AMBIENT. FIG .23 WATER QUALITY AS A FUNCTION OF PHENOL C O N C E N T R A T I O N . 100 90 80 70 60 D 3 o 50 40 o 30 20 1 0 0 10 20 30 40 50 60 70 80 90 Turbi di ty (Jackson Turbidity Units) 100 FIG.24 WATER QUALITY AS A FUNCTION OF TURBIDITY . 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 D i s s o l v e d So l ids (mg/ l ) FIG.25 WATER QUALITY AS A FUNCTION OF D ISSOLVED SOLIDS CONCENTRAT ION 100 0 I 2 3 4 5 6 7 8 9 10 Ammoni a (mg/ I ) FIG.26 WATER QUALITY AS A FUNCTION OF AMMONIA C O N C E N T R A T I O N . Nitrates (mg/1) FIG.27 WATER Q U A L I T Y A S A F U N C T I O N OF N I T R A T E C O N C E N T R A T I O N . 82 FIG.28 WATER QUAL ITY AS A FUNCT ION OF PHOSPHATE C O N C E N T R A T I O N . 83 done by Westwater i n i t s s t u d i e s on the p o l l u t i o n a s p e c t s o f the Lower F r a s e r R i v e r (30). I t i s , however, i m p o s s i b l e to p r e d i c t f u t u r e concen- t r a t i o n l e v e l s o f each s i n g l e , p o t e n t i a l l y t o x i c s u b s t a n c e i n the water, the sediment, and the organisms on which salmon f e e d s . Too l i t t l e i s known about s o u r c e s o f p o l l u t a n t s , pathways, a c c u m u l a t i o n r a t e s i n the food c h a i n , and f u t u r e d i s c h a r g e s t o the r i v e r . New p r o d u c t i o n p r o c e s s e s , changed consumer h a b i t s , t e c h n o l o g i c a l i n n o v a t i o n s i n t h e f i e l d o f waste water treatment, a l l bear on the c o m p o s i t i o n o f the waste e f f l u e n t s d i s - c h arged t o the F r a s e r . There i s d e f i n i t e l y a need t o g i v e t h o se who a r e i n v o l v e d i n d e c i s i o n making a t o o l which a l l o w s the assessment o f the p r e s e n t water q u a l i t y s t a t u s and a p r e d i c t i o n o f changes i n t h a t s t a t u s . A water q u a l i t y index as o u t l i n e d i n t h i s c h a p t e r , c o u l d r e f l e c t changes i n p o l l u t i o n p a t t e r n s r e s u l t i n g from f u t u r e u r ban and i n d u s t r i a l d e v e l o p - ment or b e t t e r waste tre a t m e n t p l a n t s . To have o n l y one parameter,, an index, would f a c i l i t a t e the problem o f p r e d i c t i n g t r e n d s i n water p o l l u - t i o n . F i g u r e 29 i l l u s t r a t e s what p o s s i b l e development such an index c o u l d show over time. These t r e n d c u r v e s can be based on f o r e c a s t s o f p o p u l a t i o n growth, i n d u s t r i a l a c t i v i t i e s i n the r e g i o n , waste d i s p o s a l methods, and so f o r t h . The problem o f u n c e r t a i n t y can be t a k e n c a r e o f by u s i n g upper and lower bounds a g a i n . The next important s t e p then, c o n s i s t s i n r e l a t i n g a d e c l i n i n g water q u a l i t y i n d e x t o an i n c r e a s e i n m o r t a l i t y r a t e (above n a t u r a l mort- a l i t y ) . T h i s m o r t a l i t y r a t e can a l s o be r e g a r d e d as a reduced r e p r o d u c t i o n r a t e due t o s u b l e t h a l e f f e c t s o f some p o l l u t a n t s . W i t h our p r e s e n t under- s t a n d i n g o f the problem, i n t u i t i v e judgment w i l l be r e q u i r e d t o d e v elop such f u n c t i o n a l r e l a t i o n s h i p . P o s s i b l e c u r v e s a r e shown i n F i g u r e 30. Curve I i s based on the assumption t h a t a d e c r e a s e i n water q u a l i t y w i l l FIG.30 POSS IBLE RELAT IONSHIPS B E T W E E N A WATER QUALITY INDEX AND M O R T A L I T Y R A T E ( S O C K E Y E S A L M O N ) . 85 not cause an immediate steep r i s e i n the m o r t a l i t y r a t e ( o p t i m i s t i c view). Curve I I i l l u s t r a t e s a l i n e a r r e l a t i o n s h i p , something which may be used as a f i r s t approximation. Curve I I I i l l u s t r a t e s the case where even a s l i g h t decrease i n water q u a l i t y r e s u l t s i n a sharp increase of the mor- t a l i t y r a t e ( p e s s i m i s t i c view). A set of such curves cannot be constructed i n a d e t e r m i n i s t i c way. Perhaps a f i s h e r y b i o l o g i s t who i s f a m i l i a r w i t h p o l l u t i o n e f f e c t s on f i s h would be w i l l i n g to express h i s s u b j e c t i v e judgment i n form of such graphs. The curves i n Figure 30 are h y p o t h e t i c a l at t h i s point i n time and have not been included i n the model presented i n t h i s paper. 86 CHAPTER V I I I DISCUSSION AND CONCLUSIONS In t h i s t h e s i s an attempt was made to describe p o t e n t i a l p o l l u t i o n problems i n the Lower Fraser R i v e r and to d e l i n e a t e what e f f e c t s a decrease i n water q u a l i t y may have on salmon. I t was argued that environmental degradation should not have to be proven beyond a reasonable doubt before c o r r e c t i n g measures are taken. P o l l u t i o n i s a gradual process and i n - creases as po p u l a t i o n and urban i n d u s t r i a l a c t i v i t i e s i ncrease. When planning present p o l l u t i o n abatement programs, we have to consider uncer- t a i n t i e s . Environmental s t r a t e g i e s have to be preventive r a t h e r than c o r r e c t i v e . We have j u s t begun to understand about the danger of some modern s y n t h e t i c chemical products and t h e i r p e r s i s t e n c e i n the environment. The accumulation of t o x i c m a t e r i a l s such as heavy metals, PCB's, and p e s t i - cides i n some lake and stream sediments i n Ontario should be an e a r l y warning s i g n a l to the decision-makers who are r e s p o n s i b l e f o r water q u a l i t y i n B r i t i s h Columbia. O i l p o l l u t i o n i s a p o s s i b i l i t y i n the c o a s t a l waters as soon as tankers s t a r t t r a n s p o r t i n g Alaskan o i l along the P a c i f i c coast to r e f i n e r i e s i n Western Washington. Off-shore o i l d r i l l i n g on the coast of Washington i s considered and might cause o i l s p i l l s as w e l l . A l s o , the past has shown that there are adverse environmental and e c o l o g i c a l e f f e c t s a s s o c i a t e d w i t h most l a r g e - s c a l e engineering e f f o r t s such as mining and logging operations i n the upper watershed of a r i v e r or increased harbour a c t i v i t i e s i n the estuary. We c e r t a i n l y have the c a p a c i t y to s i g n i f i c a n t l y a l t e r e c o l o g i c a l systems but i n most instances we are not able to p r e d i c t 87 the extent and nature of such changes. In the case of the Fraser R i v e r s t u d i e s conducted during the past three years by Westwater Research Centre showed that waste loadings to the r i v e r are i n c r e a s i n g and that composition of the waste water i s becoming more complex. Westwater's studies pointed out p o t e n t i a l l y harmful p o l l u - t a n t s , where to look f o r them, and what c o n t r o l options are a v a i l a b l e to the d e c i s i o n makers. Water q u a l i t y was found to be much lower i n some t r i b u t a r y sub-basins than i n the main r i v e r . A l s o , the accumulation of some substances found i n sediments or i n the t i s s u e of bottom d w e l l i n g organisms i s a matter of concern, as t h i s may have long-term b i o l o g i c a l e f f e c t s . For example, the e l i m i n a t i o n of smaller stream organisms may be l a r g e l y undetected but w i l l be c r i t i c a l f o r the stream's c a p a c i t y to sus- t a i n f i s h some of which are of great commercial and r e c r e a t i o n a l i n t e r e s t . Various planned developments could place a heavy demand on the mudflats and marshland areas, thus changing the land use p a t t e r n i n the estuary. With our present understanding of the complex i n t e r r e l a t i o n s h i p s i n the Fraser's ecosystem we are not able to q u a n t i f y most consequences that increased waste loadings or a r e d u c t i o n i n h a b i t a t may have on the p r o d u c t i v i t y of the Fraser estuary. Decisions w i t h regard to land use, i n d u s t r i a l development, e f f l u e n t standards, waste treatment technology and so f o r t h , have to be made now i n order to perserve water q u a l i t y i n a r a p i d l y developing estuary. In t h i s t h e s i s salmon has been i d e n t i f i e d as a major user of the Fraser R i v e r which requires water of good q u a l i t y . The Fraser R i v e r system i s one of the world's l a r g e s t producers of salmon. At present time, a salmon enhance- ment program w i t h p o s s i b l e expenditures of hundreds of m i l l i o n s of d o l l a r s i s i n i t s planning stage. For a f i s h e r i e s manager, t h e r e f o r e , i t seems to 88 be q u i t e important, to have an understanding of the dynamics of a salmon run. He would l i k e to know i n which l i f e stage of the salmon he should concentrate h i s e f f o r t s and increase s u r v i v a l r a t e s , or where he has to c a r e f u l l y monitor c o n d i t i o n s i n order to avoid degradation of the salmon's h a b i t a t . In t h i s t h e s i s a s p e c i f i c sockeye run was chosen to apply a new method whereby the l i f e c y c l e was d i v i d e d i n t o f i v e major l i f e stages. The area of u n c e r t a i n t y i n each l i f e stage was i n d i c a t e d by upper and lower bounds. As d i s t r i b u t i o n f u n c t i o n a normal d i s t r i b u t i o n f u n c t i o n was assumed between these bounds. This can be changed as soon as more data a l l o w a n a l y s i s of the d i s t r i b u t i o n f u n c t i o n . Mathematically the f i v e l i f e stages were combined by m u l t i p l y i n g matrices. As a r e s u l t , an expected r e t u r n value f o r each given escapement value.was computed and the range of uncer- t a i n t y was i n d i c a t e d . The advantage of having the l i f e c y c l e d i v i d e d i n t o l i f e stages l i e s i n the f a c t that changes i n each l i f e stage due to enhancement or p o l l u t i o n e f f e c t s can be b u i l t i n t o the model. The model then c a l c u l a t e s the o v e r a l l e f f e c t of such changes on a d u l t r e t u r n . For the present study the p o s s i b l e increase i n m o r t a l i t y due to poor water q u a l i t y c o n d i t i o n s i n the estuary was i n v e s t i g a t e d . I t was assumed that due to s u b l e t h a l e f f e c t s the number of s u c c e s s f u l spawners a f t e r m i g r a t i n g through i n c r e a s i n g l y p o l l u t e d e s t u a r i n e waters would'decline. A l s o , s u r v i v a l rates of j u v e n i l e sockeye i n the ocean were assumed to be lower a f t e r being exposed on t h e i r downstream mi g r a t i o n to s u b l e t h a l concentrations of p o l l u t a n t s i n the Lower Fraser R i v e r . In t h i s study water q u a l i t y was not d i r e c t l y r e l a t e d to s u r v i v a l rates as too l i t t l e i s known about s u b l e t h a l e f f e c t s . Increase i n m o r t a l i t y 89 r a t e was the only parameter used to r e f l e c t worsened water q u a l i t y condi- t i o n s . The s i m u l a t i o n r e s u l t s i n d i c a t e d that at a m o r t a l i t y r a t e of about 3 0 7 o a p r o b a b i l i t y of 5 7 . e x i s t e d that the simulated salmon stock d e c l i n e d to such a low l e v e l that i t might not be able to recover. The v a l i d i t y of the numbers can be debated. Factors such as d i s t r i b u t i o n f u n c t i o n and area of u n c e r t a i n t y expressed by i t s standard d e v i a t i o n i n f l u e n c e the a c t u a l numbers. As more data become a v a i l a b l e and as we gain more know- ledge about p o l l u t a n t concentrations and t h e i r p h y s i o l o g i c a l e f f e c t s on f i s h t h i s a n a l y s i s can be reviewed and numerical values be updated. One problem to be f u r t h e r i n v e s t i g a t e d i s the p r e d i c t i o n of future water q u a l i t y c o n d i t i o n s without having to f o r e c a s t loadings of each s i n g l e p o l l u t a n t . A water q u a l i t y index to be developed f o r salmon as a major water user has been proposed. Such an index could be p r o j e c t e d on the basis of i n f o r m a t i o n about"population growth, i n d u s t r i a l development of the r e g i o n , f u t u r e waste d i s p o s a l methods and so f o r t h . As long as we can- not q u a n t i f y s u b l e t h a l e f f e c t s i n an easy manner, i t may be necessary to hypothesize various r e l a t i o n s h i p s between such a water q u a l i t y index and increases i n m o r t a l i t y r a t e . S u b j e c t i v e judgment by the expert has to be used where a n a l y t i c a l data are not a v a i l a b l e . The i n t e n t i o n of t h i s t h e s i s was to discuss the many u n c e r t a i n t i e s and complexities encountered by the d e c i s i o n maker when managing a l a r g e r i v e r system f o r m u l t i p l e water use. I n c r e a s i n g waste loadings and shore- l i n e land demands are thr e a t e n i n g the salmon i n i t s abundance. Obviously i t i s not p o s s i b l e to have a very productive salmon r i v e r and a cheap waste c a r r i e r at the same time. We cannot i n d u s t r i a l l y develop the mudflats and marshland areas without reducing the h a b i t a t of f i s h and w i l d l i f e . The salmon has disappeared from many r i v e r s i n the world because of severe 90 degradation of i t s environment. The l a r g e amounts of n a t u r a l m a t e r i a l c a r r i e d by the Fraser which give the water o f t e n a very muddy appearance i s no excuse f o r u s i n g the r i v e r as a dumping ground f o r complex and o f t e n undegradable wastes from household and i n d u s t r i e s . In ancient days the B e l l a Coola Indians used to apply c a p i t a l punishment to anyone who contaminated the r i v e r by throwing waste i n t o i t . They recognized the importance of the water f o r s u s t a i n i n g t h e i r l i v e l i h o o d and way of l i f e . I t should a l s o be mandatory f o r us to provide treatment f o r a l l discharges to the r i v e r such that t o x i c substances are removed or t h e i r concentrations are reduced to a l e v e l which do ' l not impair the p h y s i o l o g i c a l w e l l - b e i n g of f i s h . Such water q u a l i t y w i l l a l s o b e n e f i t man i n h i s various r e c r e a t i o n a l a c t i v i t i e s . 91 BIBLIOGRAPHY (1) A l a b a s t e r , J.S. (1972) "Suspended s o l i d s and f i s h e r i e s , " P r o c . R o y a l Soc. London, B r i t a i n , 180:395-406. (2) A l a b a s t e r , J.S., J.H.N. G a r l a n d , I.C. H a r t , J . F . de L.G. S o l b e ! (1972) "An approach t o the problem o f p o l l u t i o n and f i s h e r i e s . " (3) Anderson, A l i s o n A., J a y M a r t i n Anderson, L y d i a E. Mayer. (1973) "System s i m u l a t i o n t o i d e n t i f y e n v i r o n m e n t a l r e s e a r c h needs: mercury c o n t a m i n a t i o n , " Oikos 24:231-238. (4) B.C. R e s e a r c h C o u n c i l . (1971) "Water q u a l i t y s u r v e y o f the Lower F r a s e r R i v e r , " P r o v i n c i a l Power Study, B.C. Energy Board, V o l . 3, Appendix I-A, M o n t r e a l E n g i n e e r i n g Co. L t d . (5) B.C. R e s e a r c h C o u n c i l . (1973) " E n v i r o n m e n t a l s t u d i e s a t Iona I s l a n d , " Report p r e p a r e d f o r The G r e a t e r Vancouver Sewerage and D r a i n a g e D i s t r i c t . (6) B e n e d i c t , A.H., K.J. H a l l , F.A. Koch. (1973) "A p r e l i m i n a r y water q u a l i t y s u r v e y o f the Lower F r a s e r R i v e r system," Westwater Re- s e a r c h C e n t r e , U.B.C., T e c h n i c a l Report No. 2. (7) Benjamin, J.R., and C.A. C o r n e l l . (1970) ' P r o b a b i l i t y , S t a t i s t i c s and D e c i s i o n s f o r C i v i l E n g i n e e r s . M c G r a w - H i l l , New York. (8) Brown, Robert M. e t a_l. (1970) "A water q u a l i t y index;. - do we d a r e ? " Water and Sewage Works, August 1970. (9) Brox, G.H. (1975) " I n d u s t r i a l waste s u r v e y of two p a i n t manufactur- i n g i n d u s t r i e s i n the G r e a t e r Vancouver a r e a , " Term Paper f o r C.E. 567. (10) Bryan, G.W. (1971) "The e f f e c t s o f heavy metals ( o t h e r t h a n mercury) on marine and o t h e r e s t u a r i n e organisms," P r o c . R o y a l Soc. London, B r i t a i n , B 177:389-410. (11) C o u n c i l on E n v i r o n m e n t a l Q u a l i t y , 3 r d A n n u a l Report, U.S. Gov. P r i n t . O f f i c e , Wash., D.C, 1972. (12) Dalkey, N., and 0. Helmer. (1963) "An e x p e r i m e n t a l a p p l i c a t i o n o f the D e l p h i method t o the use of e x p e r t s , " Management S c i e n c e , 9:458-467. (13) D a v i s , J.C. (1973) " S u b - l e t h a l e f f e c t s o f b l e a c h e d k r a f t p u l p m i l l e f f l u e n t on r e s p i r a t i o n and c i r c u l a t i o n i n sockeye salmon," J . F i s h . Res. Bd. Canada, 30:269-377. 92 (14) Dorcey, A. " P o l i c y mechanisms f o r water q u a l i t y management i n a m e t r o p o l i t a n r e g i o n , " p u b l i s h e d i n The p r a c t i c a l a p p l i c a t i o n o f economic i n c e n t i v e s t o t h e c o n t r o l o f p o l l u t i o n : The c a s e o f B r i t i s h Columbia, U.B.C. P r e s s , i n p r e p a r a t i o n . (15) F a i r b a i r n , Bruce, and Ken P e t e r s o n . (1975) " C o n t r o l l i n g sawlog d e b r i s i n the Lower F r a s e r R i v e r , " Westwater R e s e a r c h C e n t r e , U.B.C., T e c h n i c a l Report No. 5. (16) . (1975) " F i s h e r i e s r e s o u r c e s and food web components o f t h e F r a s e r R i v e r e s t u a r y and an assessment o f the impacts o f proposed e x p a n s i o n o f the Vancouver I n t e r n a t i o n a l A i r p o r t and o t h e r d e v e l o p - ments on these r e s o u r c e s , " V o l s . I and I I , Dept. o f the Environment, F i s h e r i e s and Ma r i n e S e r v i c e , Vancouver/Nanaimo. (17) F o e r s t e r , R.E. (1968) "The sockeye salmon," F i s h . Res. Bd. Canada, B u l l . 162.. - \ll (18) Franson, Mary A. (1973) " E n v i r o n m e n t a l q u a l i t y i n G r e a t e r Vancouver," s t u d y p r e p a r e d f o r the P l a n n i n g Department, G r e a t e r Vancouver R e g i o n a l D i s t r i c t . (19) G o l d i e , C.A. (1967) " P o l l u t i o n and the F r a s e r - Repo r t I , " P o l l u t i o n C o n t r o l Board, B.C. (20) Goodlad, J.C., and T.W. G j e r n e s . (1974) " F a c t o r s a f f e c t i n g sockeye . salmon growth i n f o u r l a k e s o f the F r a s e r R i v e r system," J . F i s h . Res. Bd. Canada, 31:871-892. (21) Grande, M. (1967) " E f f e c t o f copper and z i n c on salmonoid f i s h e s , " Advances i n water p o l l u t i o n r e s e a r c h , V o l . I, P r o c . 3 r d I n t . Conf., Munich, W-Germany, Sept. 1966. (22) H a l l , K.J., F.A. Koch, and I . Y e s a k i . (1974) " F u r t h e r i n v e s t i g a t i o n s i n t o water q u a l i t y c o n d i t i o n s i n t h e Lower F r a s e r R i v e r system," Westwater R e s e a r c h C e n t r e , U.B.C, T e c h n i c a l R e p o r t No. 4. (23) H a l l , K.J., I. Y e s a k i , and J . Chan. (1976) " T r a c e metals and c h l o r i - n a t e d hydrocarbons i n the sediments o f a m e t r o p o l i t a n w a t e r s h e d , " Westwater Research C e n t r e , U.B.C, T e c h n i c a l Report No. 10. (24) H a l l , K.J., and K. F l e t c h e r . (1974) " T r a c e m e t a l p o l l u t i o n from a m e t r o p o l i t a n a r e a : Sources and a c c u m u l a t i o n i n the Lower F r a s e r R i v e r and e s t u a r y , " P r o c . o f t h e I n t e r n a t i o n a l C o n f e r e n c e on t r a n s p o r t o f p e r s i s t e n t c h e m i c a l s i n a q u a t i c ecosystems, Ottawa. (25) Hershman, S t a n l e y . (1974) "An a p p l i c a t i o n o f d e c i s i o n t h e o r y t o water q u a l i t y management," Mas t e r ' s t h e s i s , U.B.C., Department o f C i v i l Eng. (26) Holden, A.V. (1972) "The e f f e c t s o f p e s t i c i d e s on l i f e i n f r e s h w a t e r s , " P r o c . R o y a l Soc. London, B r i t a i n , 180:383-394. 93 (27) Joy, C.S. (1975) "Water q u a l i t y models o f the Lower F r a s e r R i v e r , " Westwater Research C e n t r e , U.B.C, T e c h n i c a l Report No. 6. (28) . I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission, 1949, " I n t e r i m r e p o r t on the C h i l k o R i v e r w atershed." (29) . I n t e r n a t i o n a l P a c i f i c Salmon F i s h e r i e s Commission, A n n u a l R e p o r t s , 1949-1974. (30) Koch, F.A., K.J. H a l l , and I . Y e s a k i . (1976) " T o x i c s u b s t a n c e s i n wastewater o f a m e t r o p o l i t a n a r e a , " Westwater R e s e a r c h C e n t r e , U.B.C, T e c h n i c a l Report i n p r e p a r a t i o n . (31) Langer, 0. Department o f the Environment, F i s h e r i e s and M a r i n e S e r v i c e , Vancouver, p e r s o n a l communication. (32) L a r k i n , P.A. (1971) " S i m u l a t i o n s t u d i e s o f the Adams R i v e r sockeye salmon," J . F i s h . Res. Bd. Canada, 28:1493-1502. (33) L a r k i n , P.A., and A.S. Hourston. (1964) "A model f o r s i m u l a t i o n o f the p o p u l a t i o n b i o l o g y o f P a c i f i c salmon," J . F i s h . Res. Bd. Canada, 21(5):1245-1265. (34) L a r k i n , P.A., and W.E. R i c k e r . (1964) " F u r t h e r i n f o r m a t i o n on sus- t a i n e d y i e l d s from f l u c t u a t i n g e n v i ronments," J . F i s h . Res. Bd. Canada, 21(1):1-7. (35) L a r k i n , P.A. (1973) "Some o b s e r v a t i o n s on models o f s t o c k and r e - c r u i t m e n t r e l a t i o n s h i p s f o r f i s h e s , " C o n s e i l I n t e r n a t i o n a l pour 1 ' e x p l o r a t i o n de l a mer, e x t r a i t des r a p p o r t s e t proces-verbaux, V o l . 164. (36) L a r k i n , P.A., and Graduate S t u d e n t s . (1959) "The e f f e c t s on f r e s h water f i s h e r i e s o f man-made a c t i v i t i e s i n B.C.," Canadian F i s h C u l t u r i s t , 25:1-33. (37) Lewis, A.G., and P.H. W h i t f i e l d . (1974) "The b i o l o g i c a l importance o f copper i n the s e a , " r e p o r t p r e p a r e d f o r the I n t e r n a t i o n a l Copper R e s e a r c h A s s o c i a t i o n . (38) L l o y d , R. (1972) "Problems i n d e t e r m i n i n g water q u a l i t y c r i t e r i a f o r f r e s h w a t e r f i s h e r i e s , " P r o c . R o y a l Soc. London, B r i t a i n , 180:439- 449. (39) Martens, D.W., and J.A. S e r v i z i . (1974) "Acute t o x i c i t y o f m u n i c i p a l sewage t o f i n g e r l i n g sockeye salmon," I n t . Pac. Salmon F i s h . Comm. P r o g r e s s Report No. 29. (40) Martens,, D.W., R.W. Gordon, and J.A. S e r v i z i . (1971) " T o x i c i t y and treatment o f d e - i n k i n g wastes c o n t a i n i n g d e t e r g e n t s , " I n t . Pac. Salmon F i s h . Comm. P r o g r e s s Report No. 25. 94 (41) Meyer, P h i l i p A. (1974) " R e c r e a t i o n a l and p r e s e r v a t i o n v a l u e s a s s o c i a t e d w i t h the salmon o f the F r a s e r R i v e r , " Environment Canada, I n f o r m a t i o n R e p o r t S e r i e s No. PACIN-74-1. (42) Nemerov, N.L. (1974) S c i e n t i f i c s t ream p o l l u t i o n a n a l y s i s , ; McGraw- H i l l , New York. (43) N o r t h c o t e , T.G. (1974) " B i o l o g y o f the Lower F r a s e r R i v e r : A Review," Westwater R e s e a r c h C e n t r e , U.B.C, T e c h n i c a l R e p o r t No. 3. (44) N o r t h c o t e , T.G., N.T. J o h n s t on, and K. Tsumura. (1975) " T r a c e m e t a l c o n c e n t r a t i o n s i n Lower F r a s e r R i v e r f i s h e s , " Westwater R e s e a r c h C e n t r e , U.B.C, T e c h n i c a l Report No. 7. (45) O'Connor, M.F. (1972) "The a p p l i c a t i o n o f m u l t i a t t r i b u t e s c a l i n g p r o c edures t o the development o f i n d i c e s o f water q u a l i t y , " Ph.D. t h e s i s , U n i v e r s i t y o f M i c h i g a n , Ann A r b o r . (46) . " P a c i f i c s a l m o n i d enhancement program," i n f o r m a t i o n paper, Department o f the Environment, F i s h e r i e s and M a r i n e S e r v i c e , May 1975. (47) P a r s o n s , T.R., C A . Bawden, and W.A. Heath. (1973) " P r e l i m i n a r y s u r v e y of mercury and o t h e r metals c o n t a i n e d i n aminals from the F r a s e r R i v e r m u d f l a t s , " J . F i s h . Res. Bd., 30:1014-1016. (48) Pearson, N. (1972) " F r a s e r R i v e r h a r b o u r development s t u d y . " (49) P e t e r s o n , K., and T. O'Riorden. "Water q u a l i t y i n the Lower F r a s e r : O p i n i o n s and p r e f e r e n c e s o f Lower M a i n l a n d r e s i d e n t s , " u n p u b l i s h e d . (50) P i p p y , J.H.C., and G.M. Hare. (1969) " R e l a t i o n s h i p o f r i v e r p o l l u t i o n t o b a c t e r i a l i n f e c t i o n i n salmon and s u c k e r s , " T r a n s . Am. F i s h . S o c , 98:685-690. (51) . (1973) "Proposed water q u a l i t y i n f o r m a t i o n , " Volume. I I , US/EPA, Washington, D.C 20460. (52) R i c k e r , W.E. (1958) "Maximum s u s t a i n e d y i e l d from f l u c t u a t i n g e n v i r o n - ments and mixed s t o c k , " J . F i s h . Res. Bd. Canada, 15(5):991-1006. (53) S e r v i z i , J.A., and D.W. Martens. (1974) " P r e l i m i n a r y s u r v e y o f t o x i c i t y o f c h l o r i n a t e d sewage t o sockeye and p i n k salmon," I n t . Pac. Salmon F i s h . Comm. P r o g r e s s Report No. 30. (54) S e r v i z i , J.A., and R.A. B u r k h a l t e r . (1970) " S e l e c t e d measurements o f water q u a l i t y and b o t t o m - d w e l l i n g organisms o f the F r a s e r R i v e r system 1963 t o 1968," I n t . Pac. Salmon F i s h . Commission. (55) Sheehan, S. (1976) " D e c i s i o n t h e o r y as a t o o l i n sockeye salmon management of the Babine system," M a s t e r ' s t h e s i s , U.B.C, Dept. of C i v i l Eng. 95 (56) Shepard, M.P., and F. C W i t h l e r . (1958) "Spawning s t o c k s i z e and r e s u l t a n t p r o d u c t i o n f o r Skeena s o c k e y e , " J . F i s h . Res. Bd. Canada, 15(5):1007-1025. (57) Shepard, M.P., F.C. W i t h l e r , J . McDonald, and K.V. Aro. (1964) " F u r t h e r i n f o r m a t i o n on spawning s t o c k s i z e and r e s u l t a n t produc- t i o n f o r Skeena s o c k e y e , " J . F i s h . Res. Bd. Canada, 21:1329-1331. (58) Sprague, John B., and Donald E. Drury. (1969) "Avoidance r e a c t i o n s o f s a l m o n i d f i s h t o r e p r e s e n t a t i v e p o l l u t a n t s , " Advances i n water p o l l u t i o n r e s e a r c h , P r o c . of the 4 t h I n t . Conf., Prague, 1969. (59) Sprague, John B. (1969) "Measurement of p o l l u t a n t t o x i c i t y t o f i s h , " Water Res. 3:793-821. (60) Sprague, J.B. (1964) "Avoidance o f c o p p e r - z i n c s o l u t i o n s by young salmon i n t h e l a b o r a t o r y , " J . Wat. P o l l u t i o n C o n t r o l Fed., 36:990-1004. (61) T a k a h a s h i , M. I n s t i t u t e o f Oceanography U.B.C, p e r s o n a l communication. (62) Takahashi,- M., K. F u j i i , and T.R. P a r s o n s . (1973) " S i m u l a t i o n s t u d y o f p h y t o p l a n k t o n p h o t o s y n t h e s i s and growth i n t h e F r a s e r R i v e r e s t u a r y , " M a r i n e B i o l o g y , V o l . 19, No. 2:102-116. (63) . "The L i v e a b l e R e g i o n 1976/1986," p r o p o s a l s t o manage the growth o f G r e a t e r Vancouver, The G r e a t e r Vancouver R e g i o n a l D i s t r i c t , 1975. (64) -• "The Lower M a i n l a n d ' s economy," G r e a t e r Vancouver R e g i o n a l D i s t r i c t P l a n n i n g Department, 1970. (65) Thomas, W i l l i a m A. (1972) " I n d i c a t o r s o f e n v i r o n m e n t a l q u a l i t y , " Plenum P r e s s . (66) Thompson, J . P a c i f i c Environment I n s t i t u t e , Department o f t h e Environment, West Vancouver, p e r s o n a l communication. (67) W a l t e r s , C a r l J . (1975) " O p t i m a l h a r v e s t s t r a t e g i e s f o r salmon i n r e l a t i o n t o e n v i r o n m e n t a l v a r i a b i l i t y and u n c e r t a i n p r o d u c t i o n p a r a m e t e r s , " J . F i s h . Res. Bd. Canada, 3 2 ( 1 0 ) : 1777-1784. (68) ,;. Water R i g h t s Branch, B r i t i s h Columbia, p e r s o n a l communica- t i o n . (69) W i l l i a m s , I.V. (1969) " I m p l i c a t i o n o f water q u a l i t y and s a l i n i t y i n the s u r v i v a l o f F r a s e r R i v e r sockeye s m o l t s , " I n t . Pac. Salmon F i s h . Comm. P r o g r e s s R e p o r t No. 22. (70) W i l s o n , R.C.H. (1972) " P r e d i c t i o n o f copper t o x i c i t y i n r e c e i v i n g w a ter," J . F i s h . Res. Bd. Canada, 29:1500-1502. (71) Woodey, J . I n t . Pac. Salmon F i s h . Commission, New Westminster, B.C., p e r s o n a l communication. 96 APPENDIX 1 LOGNORMAL VERSUS NORMAL DISTRIBUTION Very o f t e n the u n c e r t a i n t y i n a p h y s i c a l v a r i a b l e r e s u l t s from the f l u c t u a t i o n of many f a c t o r s each of which i s d i f f i c u l t to i s o l a t e and to observe. In the case of salmon, f o r example, some l i f e stages are governed by various environmental f a c t o r s , such as temperature, oxygen, water flow, lake p r o d u c t i v i t y ( i n i t s e l f a composite of many f a c t o r s ) , predation, and so f o r t h . I f we know the mechanism by which these f a c t o r s a f f e c t the v a r i a b l e of i n t e r e s t we can de r i v e the d i s t r i b u t i o n f u n c t i o n f o r t h i s v a r i a b l e without studying i n d e t a i l the i n d i v i d u a l e f f e c t s . I f the i n d i - v i d u a l causes are a d d i t i v e i n nature a p p l i c a t i o n of the C e n t r a l L i m i t Theorem w i l l lead to a normal d i s t r i b u t i o n ; i f they are m u l t i p l i c a t i v e i n nature we w i l l a r r i v e at a lognormal d i s t r i b u t i o n (7). For both cases i t i s necessary that the number of causes be e i t h e r l a r g e or that each of them have only a small e f f e c t on the sum (product). In other words, none of them should be dominating. A normal d i s t r i b u t i o n can be w r i t t e n i n i t s standard form as: 1 (1) f ( x ) = exp [-| ( X " l° x) 2] x x a , the standard d e v i a t i o n , and m^ s the mean value, are two parameters which describe t h i s d i s t r i b u t i o n f u n c t i o n (Figure 1A). The normal d i s t r i - . bution i s symmetrical w i t h regard to the mean value. In the case of t h i s study a normal d i s t r i b u t i o n f u n c t i o n was assumed to describe the values between upper and lower curves. The d i s - tance between mean and upper or lower bound was assumed to be two standard 97 d e v i a t i o n s . The area under the normal d i s t r i b u t i o n f u n c t i o n i s defined as 1.0. By c u t t i n g o f f the t a i l s one has to introduce a c o r r e c t i o n f a c t o r which normalizes a l l computed p r o b a b i l i t i e s . Using two standard d e v i a t i o n s t h i s f a c t o r i s 1 . 1 - 0.0455 While a normal d i s t r i b u t i o n r e s u l t s from the summation of many small e f f e c t s , i t i s d e s i r a b l e a l s o to consider the d i s t r i b u t i o n f u n c t i o n which a r i s e s as the r e s u l t of the m u l t i p l a t i v e nature of random events. A f r e q u e n t l y used example i s that of sediment t r a n s p o r t i n streams where the f i n a l s i z e of a p a r t i c l e r e s u l t s from a number of c o l l i s i o n s of p a r t i c l e s of many, s i z e s t r a v e l l i n g at d i f f e r e n t v e l o c i t i e s . Each c o l l i s i o n reduces the p a r t i c l e by a random p r o p o r t i o n of i t s s i z e at the time. Therefore, the s i z e Y n a f t e r the n1-*1 c o l l i s i o n i s the product of Y n_^ ( i t s s i z e p r i o r to that c o l l i s i o n ) and Wn (the random r e d u c t i o n f a c t o r ) . Mathematically, we can formulate t h i s c hain process as: (2) Y n = Y n_ x Wn = Y n. 2 Wn_x Wn = . .. . Y ^ ^ . . . .Wn The processes governing the salmon's l i f e c y c l e can be thought analogously. As an example, l e t us consider the l i f e stage Eggs desposited/Fry produced. Various random processes a f f e c t t h i s l i f e stage. The f i n a l number of sur- v i v i n g f r y w i l l be the number of eggs i n i t i a l l y deposited m u l t i p l i e d by the s u r v i v a l r a t e a f t e r each random process has occurred. For example, the number of eggs which have su r v i v e d an unfavourable water temperature or a low^oxygen c o n c e n t r a t i o n may a l s o be subjected to washouts due to extreme flow c o n d i t i o n s or predation by other f i s h , or may, i n a d d i t i o n , become exposed to severe i c e c o n d i t i o n s . In a l l these cases where the v a r i a b l e of i n t e r e s t Y can be expressed as the product of a number of v a r i a b l e s we can apply the f o l l o w i n g . Taking 98 the n a t u r a l logarithms of both sides i n equation (2) leads to: In Y = In Y„ + I n W, + In W9 + In W : n o 1 / n Since the Wn are random v a r i a b l e s , the functions In Wn are a l s o random v a r i a b l e s . A p p l y i n g the C e n t r a l L i m i t Theorem, one can say that the sum of a number of these v a r i a b l e s w i l l be approximately normally d i s t r i b u t e d . In t h i s case, then we expect In Y to be normally d i s t r i b u t e d . A random v a r i a b l e Y whose logarithms are normally d i s t r i b u t e d i s s a i d to have a lognormal d i s t r i b u t i o n . The most common form to w r i t e the lognormal p r o b a b i l i t y d i s t r i b u - t i o n f u n c t i o n i s : <3> w = y v ^ c , e x p { -i kr- l n f : ) ] 2 } y l n y l n y ffi^ where mv i s the median of the random v a r i a b l e Y and a ^ n y i s the standard d e v i a t i o n . The median m i s defined as that value below which one-half of y the p r o b a b i l i t y mass l i e s . In comparison to a normal d i s t r i b u t i o n a lognormal d i s t r i b u t i o n i s skewed i n shape. Depending on the value f o r a^ny t h i s skewness can be more or l e s s accentuated. Figure 2A i l l u s t r a t e s some cases. The lognormal d i s t r i b u t i o n i s o f t e n used as a model where the observed data are found to be skewed. In order to v e r i f y a lognormal d i s t r i b u t i o n governing some stages i n the l i f e c y c l e of sockeye salmon, more data than p r e s e n t l y a v a i l - able are required to do a s t a t i s t i c a l a n a l y s i s . 99 f (x) FIG.IA NORMAL PROBABILITY DISTRIBUTION. 0 Y FIG.2A LOGNORMAL PROBABILITY DISTRIBUTIONS FOR DIFFERENT STANDARD DEVIATION VALUES (After Benjamin and Cornell.) Appendix 2 Flow Chart o f the model S t a r t i Main Program I C a l l s s u b r o u t i n e s S P U N , I N T G V P R M A T , S U M I N T , B A L , M U L T E X P R E T READ i n Data P o i n t s o f Lower, median and upper curve. F i t s a c u b i c polynomial curve through the p o i n t s . C a l c u l a t e s i n t e r p o l a t e d values at a number o f i n p u t a b s c i s s a e S P U N Reads i n number o f I n t e g r a t i o n l i n e s and l e n g t h of i n t e g r a t i o n i n t e r v a l s . Uses Trapez-Formula t o approximate areas under normal curve Writes p r o b a b i l i t i e s i n mat r i x form I N T G SUMS UP areas, under normal d i s t r i b u t i o n S U N I N T Balances l a s t elements i n rows of ma t r i x where necessary so t h a t t o t a l area equals 1.0 B A L P r i n t s balanced p r o b a b i l i t y m a t r i x P R M A T 101 MULT Yes Given an escapement value EXPRET c a l c u l a t e s expected r e t u r n s by m u l t i p l y i n g p r o b a b i l i t i e s o f l a s t p roduct matrix w i t h median of each r e t u r n c l a s s and forming the sum EXPRET ( STOP ^

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