SECTION 6 



BIOENERGETIC AND OTHER CONSIDERATIONS IMPORTANT IN THE STUDY OF 

 WATER QUALITY INFLUENCES ON FISH GROWTH 



Peter Doudoroff 



The determination of maximum permissible concentrations of water pollu- 

 tants in waters in which fish must be adequately protected has long been a 

 major objective of physiological, toxicological , and ecological research in 

 the field of water pollution in the United States and in the Soviet Union. 

 We have fully recognized that prevention of fish mortalities is not alone a 

 sufficient goal of pollution control directed toward the protection of 

 fisheries, for unimpaired fish production clearly depends upon adequate re- 

 production and normal growth of fish, and not only on their survival. 

 However, research into the effects of water pollutants on fish growth has 

 been limited, and much of it is rather crude or superficial and not \jery 

 helpful in the prediction of effects under natural environmental condi- 

 tions. Effects on reproduction, which certainly is essential to fish pro- 

 duction, have received more attention. But some interference with reproduc- 

 tion of fish may sometimes have relatively little or no effect on their 

 production, because numbers of young produced remain sufficient for nearly 

 full utilization of the available habitat and food resources. Production 

 (elaboration of new tissues) may even increase under some circumstances, 

 because reduced competition for food permits a larger portion of the food 

 materials and energy to be utilized for accelerated growth and less for 

 maintenance metabolism. On the other hand, any interference by pollution 

 with the growth of the young must necessarily result in impairment of 

 production. 



To understand effects of environmental factors on the growth of 

 animals, it is essential to consider to what extent and to what ends the 

 energy and materials of food consumed by the animals are utilized and how 

 they are distributed, under the different conditions, among portions having 

 different fates. It is not my purpose to expound in depth here on the 

 principles of the science of bioenergetics and their application in the 

 study of the growth of fish, a field of research to which Soviet 

 scientists, notably the late V.S. Ivlev and also G.6. Vinberg, have made 

 outstanding contributions. Nor can I treat fully the influence of water 

 pollutants on fish growth. A more detailed exposition of the principles 

 involved and their applications in pollution research can be found in the 

 chapter on "Bioenergetics and Growth" of Warren's (1971) "Biology and Water 

 Pollution Control" (p. 135-167). My purpose here is, mainly, to- propose 

 and explain a general scheme of procedure, based on important bioenergetic 



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