Effects on Oysters of Increased Levels of Copper in Seawater

摘要

Sensitivity of the Pacific oyster, Crassostrea gigas, to copper was evaluated in experiments of about a 2 wk duration. Groups of 8 to 10 animals were exposed to copper concentrations ranging from 100 to 1300 micrograms/1 in a high volume, flow-through bioassay system. The greatest mortality of 96 h occurred in animals at intermediate rather than high copper concentrations. However, by correcting the duration of exposure of each oyster to copper by a factor related to the amount of time the shells were open, the authors obtained typical mortality curves. Significant mortalities occurred at copper concentrations greater or less than 200 micrograms/1. Data analysis gives and LC 5048 of 650 micrograms/1, and LC 5096 of 430 micrograms/1, and an incipient LC 50 of 230 micrograms/1. Distribution of 64CU in oysters after 24-h exposure differed between animals maintained in water containing high and low concentrations of copper. Copper flux into tissues increased with the copper concentrations in the water, indicating little metabolic regulation.