Le Tributyletain et Ses Produits de Degradation Dans L'Estuaire du Saint-Laurent (Canada) Tributyltin and Its Degradation Products in the St Lawrence Estuary (Canada)

The ubiquitous distribution of butyltins in Canadian coastal waters is now an important environmental concern and there is an urgent need for new set of data which could provide tools for an adequate environmental management. Surface sediments (first 5 cm) and mussels, collected in 1995 in four harbors and one control site located along the St Lawrence Estuary, were analyzed by gas chromatography/mass spectrometry (GC-MS) for their contain in tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT). Results from the various sites are summarized as following: the harbor of Les Mechins was the most contaminated site with an average TBT concentration (dry weight) of 40 ±12 ng Sn g−1 in sediment and 145 ± 8 ng Sn g−1 in mussels collected near the dry dock, these values corresponding to a moderately contaminated environment; sediment and mussels from Gros-Cacouna and Rimouski-Est showed low contamination with concentrations in TBT below 28 ng Sn g−1 in sediment and below 72 ng Sn g−1 in mussels. However, con...