ESTIMATION OF AMBIENT CHRONIC TOXICITY IN A POLLUTED CREEK SYSTEM

Ambient water toxicity estimations were conducted in Piles Creek as pa rt of an ecological risk assessment study. This creek is part of a hig hly polluted estuarine system located near Linden, New Jersey. An upst ream and a downstream site in the creek were evaluated for effects on survival, growth and sexual maturity of the estuarine mysid, Mysidopsi s bahia. Manasquan Inlet, Manasquan, New Jersey, served as the referen ce site. Seven-day screening toxicity tests were conducted once a mont h over a three month period. Results indicate that survival of mysids was not affected in any toxicity test. Mysid growth was significantly reduced at both of the test sites, in two out of three trials. Sexual maturity was shown to be adversely affected in mysids exposed to ambie nt waters from both test sites throughout the duration of the study.