Comparative toxicity of chlorine and peracetic acid in the biofouling control of Mytilopsis leucophaeata and Dreissena polymorpha embryos (Mollusca, Bivalvia)

Chlorination is the most common antifouling procedure, but the search for alternatives is ongoing. Although concentrations that kill adults will also be effective against larvae, it is advisable to evaluate the toxicity of any candidate toxicant against the combatable life stage. For mussels, the earliest life stages are the most vulnerable ones and thus may require the lowest doses biocides. Since the period of larval presence is restricted to a couple of months, a pointed dosage of biocides during this period will be as effective as a continuous dosage throughout the year. This study reports on the lethal acute toxicity of sodium hypochlorite and peracetic acid to 4 h old embryos of Mytilopsis leucophaeata and Dreissena polymorpha. Chlorination was found effective against M. leucophaeata from a concentration of 0.6 mg/l onwards, even at short exposure times. Commercial peracetic acid showed to be a very good alternative in both species although the most appropriate level still has to be determined. (C) 2009 Elsevier Ltd. All rights reserved.