Acclimation temperature: an important factor in power plant chlorination studies with larval white perch, Morone...

Larval white perch were subjected to interacting power plant conditions of total residual chlorine (0.00-0.30 mg/l), elevated temperature (2, 6, and 10 degrees C), and exposure time (0.08, 2.0, and 4.0 h) at acclimation temperatures of 15 and 23 degrees C. Mortality observations were conducted up to 96 h after exposure. Acclimation temperature was a significant factor contributing to the effects of simulated power plant conditions during the low and high thermal conditions. Larvae tested at 23 degrees C generally showed greater mortality at all treatment levels than those tested at 15 degrees C. Mortality of test organisms during a 4-h exposure at the higher acclimation temperature was greater than 85% at elevated temperatures greater than 6 degrees C regardless of other treatment factors. Mortalities as low as 30% were observed at the lower acclimation temperature.