Development of a sublethal test to determine the effects of copper and lead on scleractinian coral larvae.

Abstract

A new sublethal toxicity test was developed in this study to measure the effect of copper and lead on the motility of coral larvae. Larval motility was significantly affected by copper and lead doses immediately after dosing. The copper EC50 values for motility of Goniastrea aspera brain coral larvae (12 h, 21 microg/L; 24 h, 16 microg/L; 48 h, 22 microg/L) were much lower than the copper LC50 values for G. aspera larval survival (6 h, 260 microg/L, and 24 h, 121 microg/L, for 5-day-old larvae and 6 h, 248 microg/L, and 24 h, 136.64 microg/L, for 6-day-old larvae) during the early part of the experiments. However, at later times, the LC50 values (48 h, 40 microg/L, for 5-day-old larvae and 48- h, 87 microg/L, for 6-day-old larvae) were similar to the EC50 values for larval motility. The lead 72-h EC50 value for G. aspera larval motility (2900 microg/L) was much lower than the lead 72-h LC50 value for larval survival (9890 microg/L). The results show that larval motility can be a useful parameter to measure in order to determine the sublethal effects of trace metals on coral larvae.