Response of mussel recruits to pollution from the ‘Prestige’ oil spill along the Galicia coast. A biochemical approach

Postlarval recruits of mussels Mytilus galloprovincialis were sampled in February 2003 at 7 localities along the Galicia coast (NW Spain) exhibiting different levels of impact from the ‘Prestige’ oil spill. These localities are important grounds for seed collection used in raft culture. The concentrations of polycyclic aromatic hydrocarbons (PAHs) as well as different biochemical and ecophysiological variables were determined in mussel tissues, as indicators of the toxic impact of the spilled oil. The following parameters were measured: size frequency distributions and size–weight relationships, survival in air, biochemical composition (proteins, carbohydrates, glycogen and lipids), lipid classes (phospholipids, sterol esters and waxes, triacylglycerols, free fatty acids and sterols), and fatty acid composition. The study determined sub-lethal effects in wild mussel seed populations sampled 3 mo after the oil spill. These effects are shown in the form of survival indices and alterations of lipid metabolism, especially in trygliceride and sterol fractions, as well as in saturated/monounsaturated fatty acid ratios. Monitoring these effects in wild mussel recruits is important for analysing growth, production and biochemical reserve cycle throughout the raft cultivation period and evaluating the capacity of the individuals to repair alterations detected in the juvenile stage.