You are here:
INCREASED TOXICITY OF AMMONIA TO RAINBOW TROUT 'SALMO GAIRDNERI' RESULTING FROM REDUCED CONCENTRATIONS OF DISSOLVED OXYGEN
Citation:
Thurston, R., G. Phillips, AND R. Russo. INCREASED TOXICITY OF AMMONIA TO RAINBOW TROUT 'SALMO GAIRDNERI' RESULTING FROM REDUCED CONCENTRATIONS OF DISSOLVED OXYGEN. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-81/587.
Description:
The median lethal concentration (LC50) of aqueous ammonia at reduced dissolved oxygen (D.O.) concentrations was tested in acute toxicity tests with rainbow trout (Salmo gairdneri) fingerlings. Fifteen 96-h flow-through tests were conducted over the D.O. range 2.6-8.6 mg/L, the former concentration being the lowest at which control fish survived. There was a positive linear correlation between LC50 (milligrams per liter un-ionized ammonia) and D.O. over the entire D.O. range tested; ammonia toxicity increased as D.O. decreased. Ammonia LC50 values were also computed for 12, 24, 48, and 72 h; the correlation with D.O. was greater the shorter the time period.