Toxicological response of Amphibalanus amphitrite larvae as an indirect evaluation of antifouling paints’ efficacy

Abstract

The evaluation of new antifouling paints is usually performed through long and expensive field tests (raft-tests), often depending on the season of exposure. Particularly in the Mediterranean Sea, these tests are representative only if carried out during spring or summer. Therefore, it is strategically important to develop laboratory methods that are able to test and select, during winter, the best formulations to submit to raft-test during the summer. For this reason, an acute toxicity bioassay using larvae (Stage II nauplii) of Amphibalanus amphitrite on paint leaching products obtained with an accelerated ageing system was tested as a tool for the indirect evaluation of antifouling efficacy. Seven experimental paint formulations were selected on the basis of previous obtained field efficacy performances, and were subjected to both laboratory bioassays and to a 12-month raft-test. The data show how paint behaviour (expressed as fouling coverage percentage) after 12 months of immersion in the field could be predicted by the results of laboratory bioassays, expressed as immobilisation percentage of larvae exposed for 48 h to leaching products of artificially aged paints.