Abstract
| - Aliphatic and aromatic hydrocarbons were determined intissues of mussels (Mytilus edulis), clams (Tapessemidecussata), cockles (Cardium edule), and oysters(Ostrea edulis), collected 3, 6, 9, 12, and 34 months afterthe Aegean Sea oil spill occurred in the Galicia coast (NWSpain) in December 1992. Petroleum uptake was confirmedby the presence of an unresolved complex mixture ofhydrocarbons containing fossil markers, such as triterpanesand saturated and aromatic steranes. These markerswere useful in assessing the spatial and temporal evolutionof the spilled oil in the area, resulting in the pregnanederivatives particularly enriched in the bivalve tissues. Thedistribution of parent 3−6-ring polycyclic aromatichydrocarbons reflected the concurrence of oil residuesand combustion products, possibly from the tanker fire.These distributions were depleted in higher ring componentswith respect to those found in sediments, indicating alower bioavailability of the pyrogenic components but alonger persistence in time. Qualitative and quantitativedifferences in bioaccumulation were found among bivalves,sampling sites and over time. Aliphatic and aromatichydrocarbons also exhibited different bioaccumulationtrends. A significant decline of the hydrocarbon contentswas particularly evident from 3 to 6 months after the accident,although incidental increases, probably related to theresuspension of the polluted sediments by stormy weather,were observed.
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