Karen M. Fitzmayer

Acute Toxicity Effects of Simazine on Daphnia Pulex and Larval Striped Bass

Tests were performed to determine the acute toxicity of simazine, a herbicide commonly used in pond aquaculture, to the cIadoceran Daphnia pulex and to 3- and 7-day old larval striped bass (Morone saxatilis). The 48-hour LC50 for 3-day-old striped bass was r8 mglIiter in hard water (220 mg/liter as CaC03 ) and r6 mglIiter in soft water (120 mglIiter as CaC03 ); corresponding estimates for 7-day-old larvae exceeded roo mg/liter. The estimated 48-hour LC50 for D. pulex exceeded 50 mg/liter in both hard and soft water. These estimates were considerably higher than recommended pond application...