The Development of Ecotoxicological Criteria in Urban Catchments

Abstract

Metal uptake and mortality rates are determined for selected body areas of Gammarus pulex under both in-situ stream and laboratory test conditions. Metal equilibrium concentration levels are chieved in soft tissue within 5 to 6 weeks exposure in the field with four-to five-fold increases over background control levels noted for saturation levels in caged organisms at sites subject to sewer discharges. Laboratory bioassays yield short-term LC20 values in the order Pb>Cu>Zn, although there is little difference in metal toxicities over exposure periods of about one week. The controlled toxicity tests demonstrate a substantial short-term toxic enhancement over the in-situ field bioassays.