importance of this toxicant in potential fish producing waters is often not 

 evaluated. Comparison of LC^g levels with those which have adverse effects 

 after long exposure indicates that the 96-hr LC50 may be 3 to 8 times 

 higher than the safe levels. The present work, and that of Smith and Oseid 

 (1974), who examined the effect of hydrogen sulfide on early life history 

 stages of 8 species of freshwater fish, show that a safe level of hydrogen 

 sulfide which will insure survival and growth of a fish population, and 

 adequate survival of all life history stages will generally be between 

 0.002 and 0.004 mg/1 at 20 °C. In bluegills, the level is significantly 

 lower, and this pattern may be followed in other species not tested. 



REFERENCES 



American Public Health Association, American Water Works Association, Water 

 Pollution Control Federation. 1971. Standard methods for the examina- 

 tion of water and wastewater. 13th ed. New York, Am. Pub. Health 

 Assoc. , Inc. 874 p. 



Adelman, I.R. 1969. Survival and growth of northern pike {Etox Iuc-Lua L.) 

 in relation to water quality. Ph.D. Thesis, Univ. of Minnesota, St. 

 Paul, Minnesota. 195 p. 



Adelman, I.R. and L.L. Smith, Jr. 1970. Effect of hydrogen sulfide on 

 northern pike eggs and sac fry. Trans. Amer. Fish. Soc. 99: 501. 



Adelman, I.R. and L.L. Smith, Jr. 1972. Toxicity of hydrogen sulfide to 

 goldfish {Cancutiui, auncitiLi) as influenced by temperature, oxygen, and 

 bioassay techniques. J. Fish. Res. Bd. Canada 29: 1309. 



Colby, P.J. and L.L. Smith, Jr. 1967. Survival of walleye eggs and fry on 

 paper fiber sludge deposits in the Rainy River, Minnesota. Trans. 

 Amer. Fish. Soc. 96: 278. 



Mount, D.I. and W.A. Brungs. 1967. A simplified dosing apparatus for 

 toxicological studies. Water Res. 1: 12. 



Scidmore, W.J. 1956. An investigation of carbon dioxide ammonia and 

 hydrogen sulfide as factors contributing to fish kills in ice covered 

 lakes. Minn. Dept. Conser. Bur. Res. Plann., Invest. Rep. 177: 9. 



Smith, L.L., Jr. and D.M. Oseid. 1974. Effect of hydrogen sulfide on 

 development and survival of eight freshwater fish species. In: The 

 Early Life History of Fish. Blaxter, J.H.S. (ed.). Springer-Verlag, 

 New York. p. 416-430. 



121 



