Organohalogenated contaminants in harbour porpoises
Determination of organohalogenated contaminants in liver of harbour porpoises (Phocoena phocoena) stranded on the Belgian North sea coast
Context of the study
The harbour porpoise is a vulnerable species in European waters. During the past decades the number of observations of this cetacean have decreased. Although observations along the coast of the Netherlands have increased since 1990, this trend is more likely to reflect a shift in distribution of harbour porpoises, than an actual increase of the population. [1] One of the main threats to the harbour porpoise is accidental capture by fishing gear. High levels of contaminants, declining fish stocks and other anthropogenic stress factors (wind mills, sonar, shipping,... [2]) are also considered possible threats.
Content of the study
The study evaluates the occurrence and trends of important organic contaminants in the harbour porpoise: one of the top predators in of the North Sea ecosystem. The study specifically evaluates the occurrence of PBDE's, PCB's and organoclorine pesticides. Harbour porpoises don't migrate on a large scale, and are therefore a suitable indicator for local pollution. This study is based on liver samples of 21 harbour porpoises, which stranded along the Belgian coast between 1997 and 2000.
Results of the study
Organoclorine pesticides occured in low concentrations, while relatively high values of PCB's, PBDE's were measured. (PCB's averaged 36,4 µg/g, PBDE's averaged 2,3 µg/g)
