In Galician coast the mussel culture is carried out in wooden floating rafts which are cleaned in situ with tars or waterproof paints. The spillage of these substances around rafts entails a direct pollution risk in aquaculture areas. This work analyses the composition, toxicity and mutagenicity of four compounds generally used in these tasks in order to identify their pollutant contribution and to improve mussel farming practices, therefore ensuring its sustainability. The toxic risk due to PAHs composition was determined by the TEQ calculation in reference to the toxicity of BaP. The mutagenicity was evaluated by a test based on detection of neomycin-resistant mutants of Vibrio harveyi, considering the metabolic bioactivation of the compounds analysed. The real toxicity of these compounds, determined by their mutagenic potential, is dependent of their solubility, bioavailability and biodegradability which, in turn, vary depending of the concentration and composition. Our results reveal that the waterproof paints and the pine tar are more suitable for the maintenance of mussel rafts decreasing the toxic risks, and suggest the convenience of a regulation and control of the maintenance tasks of mussel rafts.
