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.Scientific relevance: This paper gives valuable information on the increasing biofouling problem of the invasive bivalve M. leucophaeata and the possible control and avoidance of its biofouling. Instead of acting in a reactive way, this is combating the fouling problem after mussels have settled, we are looking at the problem in a proactive way. Next to the common antifouling procedure of chlorination, also peracetic acid is considered as an alternative. The procedures were tested for M. leucophaeata and the zebra mussel, D. polymorpha. This makes comparison between both species more easy. |
