Chlorine, temperature, and exposure duration effects of power plant effluents on juvenile blue crabs Callinectes sapidus and grass shrimp Palaemonetes pugio.

Abstract

The effects of interacting Cl, temperature, and exposure conditions similar to those found in power plant effluents were assessed for the blue crab Callinectes sapidus and the grass shrimp Palaemonetes pugio. Test organisms were exposed to total residual Cl (TRC) concentrations of 0.00, 0.15, and 0.30 mg/l in combination with temperatures 2, 6, and 10°C above ambient for 0.08, 2.0, and 4.0 h. The TRC concentrations were decayed over a 1–1.5‐h period to <0.0l mg/l. Temperatures were decayed over a 4‐h period to 2°C above ambient. These conditions were used to simulate Cl and temperature conditions encountered in power plant discharge canals and near‐field receiving streams. Regression model techniques were used to establish the interaction of Cl, temperature excess ( δ1), and exposure duration as factors that caused death up to 36 h after the exposure period. Mortality increased for grass shrimp as the Cl concentration, δT, and length of exposure increased. A percentage mortality model for grass shrimp sho...