RAISIN RIVER/MONROE HARBOR SURVEY I / JULY 12-19, 1983

Abstract

Fathead minnows, 24 hr old, were shipped air freight from the EPA laboratory in Newtown, OH. The larval fathead minnows were exposed to 10 water sources from the Raisin River/Monroe Harbor area of southeastern MI. They were designated as station numbers 1-6, 8, 9, 11 and prechlorinated Waste Water Treatment Plant (WWTP) effluent. Water from station #11 was filtered (20 µ) Lake Erie water and served as control water. Methods in the proposed "Seven-Day Early Life Stage Growth Test Using the Fathead Minnow (Pimephales promelas) " by Teresa J. Norberg and Donald I. Mount (draft manuscript) were followed during exposures. Exposure chambers were arranged randomly in a temperature-controlled room. The chambers were covered with clear plastic between observations for additional temperature control and temperatures were measured daily in randomly selected chambers. Observations of the fish were made daily in all chambers for mortalities or effects. Water was collected daily from the sources for renewal in each chamber. The water was monitored daily for conductivity, dissolved oxygen, pH and total alkalinity (Table 1). Exposure waters were above 60% saturation for dissolved oxygen at the start and renewal of all exposures. One-way analysis of variance with Dunnett's procedure was performed on arcsin-transformed survival data to test for significant effects.