RICE and BAILEY: SURVIVAL, SIZE. AND EMERGENCE OF PINK SALMON 



with known densities of pink salmon alevins (Rice 

 and Bailey 1980) was 0.096 ppb. Both of these 

 "real life" extremes of NH3 were much less than 

 the concentrations we found to cause early 

 emergence of immature fry and acute toxicity. The 

 concentrations that caused small size after 

 lengthy exposure in this study were about 10 

 times greater than the maximum concentrations 

 found in hatchery incubator effluents and intra- 

 gravel water from salmon redds (Bailey et al. 

 1980; Rice and Bailey 1980). Thus, exposure to 

 naturally occurring ammonia is not a likely prob- 

 lem for salmon eggs and alevins in Alaska under 

 natural or hatchery conditions where tempera- 

 tures are low and waters are acidic — conditions 

 that cause the percentage of NH3 to be very low 

 (<0.1^f). 



If pink salmon are reared at higher tempera- 

 tures and alkalinities, the potential for adverse 

 effects from NH3 is increased because of the shift 

 in the equilibrium toward NH3. At 5° C and pH of 

 7.5, 0.394'^ of the total ammonia is NH3; in con- 

 trast, at 5° C and pH of 6.5, 0.0395^^ is NH3 ( Emer- 

 son et al. 1975). Therefore, if the pH of Auke Creek 

 and Sashin Creek were 7.5 rather than 6.5, ap- 

 proximately 10 times more NH3 might have been 

 observed. The level of total ammonia would have 

 been the same, but the percentage of NH3 would 

 have been much greater. Assuming no losses from 

 aeration or other factors, the percentage of NH3 

 would be about 100 times greater at a pH of 8.5 

 than at a pH of 6.5. It is possible that high densi- 

 ties of alevins in hatcheries or stream gravels 

 could produce unhealthy concentrations of NH3 if 

 the pH is alkaline. From our exeriments, we con- 

 clude that concentrations of NH3 >0.50 ppb should 

 be avoided. Because our results were generated at 

 relatively low temperature and pH, extrapolation 

 of our data to extreme situations of temperature 

 >10° C or pH >7.8 is inappropriate. 



ACKNOWLEDGMENTS 



Sidney G. Taylor aided in the 61-d tests and the 

 length-weight analysis. Charlotte Misch con- 

 ducted the tests on early emergence. 



LITERATURE CITED 



Bailey, J. E., S. D. Rice, J. J. Pella, and S. G. T.wlor. 



1980. Effects of seeding density of pink salmon, Oncorhyn- 

 chus gorbuscha , eggs on water chemistry, fry characteris- 

 tics, and fry survival in gravel incubators. Fish. Bull., 

 U.S. 78:649-658. 



Bams, R. A. 



1967. Differences in performance of naturally and artifi- 

 cially propagated sockeye salmon migrant fry, as mea- 

 sured with swimming and predation tests. J. Fish. Res. 

 Board Can. 24:1117-1153. 



1970. Evaluation of a revised hatchery method tested on 

 pink and chum salmon fry. J. Fish. Res. Board Can. 

 27:1429-1452. 

 BURKHALTER, D. E., AND C. M. KAYA. 



1977. Effects of prolonged exposure to ammonia on fer- 

 tilized eggs and sac fry of rainbow trout ^Salmo 

 gairdneri). Trans. Am. Fish. Soc. 106:470-475. 



doudoroff, p, b. g. anderson, g. e. burdick, r s. 

 Galtsoff, W. b. Hart, R. Patrick, E. R. Strong, E. W. 

 surber, and w. m. van horn. 



1951. Bio-assay methods for the evaluation of acute toxicity 

 of industrial wastes to fish. Sewage Ind. Wastes 

 23:1380-1397. 



Emerson, K., R. C. Russo, R. E. Lund, and R. V. Thurston. 



1975. Aqueous ammonia equilibrium calculations: effect 

 of pH and temperature. J. Fish. Res. Board Can. 

 32:2379-2383. 



European Inland Fisheries Advisory Commission. 



1970. Water quality criteria for European freshwater fish. 

 Report on ammonia and inland fisheries. FAQ, EIFAC 

 I Eur Inland Fish. Advis. Comm.) Tech. Pap. 11, 12 p. 



Finney, d. j. 



1971. Probit analysis, 3d ed. Camb. Univ Press, Lond., 

 333 p. 



Garrison, R. L. 



1968. The toxicity of pro-noxfish to salmonid eggs and 

 fry. Prog. Fish-Cult. 30:35-38. 

 Parker, R. R. 



1971. Size selective predation among juvenile salmonid 

 fishes in a British Columbia inlet. J. Fish. Res. Board 

 Can. 28:1503-1510. 



Penaz, M. 



1 965 . Influence of ammonia on eggs and spawns of stream 

 trout Salmo trutta M. Fario. Zool. Listy, Folia Zool. 

 14:47-53. [Translated by and available from Foreign 

 Fisheries (Translations), U.S. Dep. Commer. Wash.. D.C.I 



Rice, S. D., and J. E. Bailey. 



1980. Ammonia concentrations in pink salmon, On- 

 corhynchus gorbuscha, redds of Sashin Creek, southeast- 

 em Alaska. Fish. Bull., U.S. 78:809-811. 



RICE, S. D., D. a. Moles, and J. W. Short. 



1975. The effect of Prudhoe Bay crude oil on survival and 

 growth of eggs, alevins, and fry of pink salmon, On- 

 corhynchus gorbuscha. In Proceedings of 1975 Confer- 

 ence on Prevention and Control of Oil Pollution, p. 503- 

 507. Am. Pet. Inst., Environ. Prot. Agency, and U.S. Coast 

 Guard, Wash., D.C. 

 RICE, S. D., AND R. M. Stokes. 



1975. Acute toxicity of ammonia to several developmental 

 stages of rainbow trout, Salmo gairdneri. Fish. Bull., 

 U.S. 73:207-211. 



Smart, G. R. 



1978. Investigations of the toxic mechanisms of ammonia 

 to fish — gas exchange in rainbow trout i Salmo gairdneri) 

 exposed to acutely lethal concentrations. J. Fish. Biol. 

 12:93-104. 



U. S. Environmental Protection Agency. 



1974. Methods for chemical analysis of water and wastes. 

 U.S. Environ. Prot. Agency, EPA-625/6-74-003, 298 p. 



647 



