The Baltic Proper, Kattegat and Skagerrak

Metal concentrations in biota; Concentration of other organic contaminants in biota

The Contaminant Programme in marine biota constitutes an integrated part of the national monitoring activities in the marine environment as well as the international programmes within ICES, OSPARCOM and HELCOM. The programme is financed by the Swedish Environmental Protection Agency. The Baltic cod is living below the halocline feeding on bottom organisms. It becomes sexually mature between 2-6 years in Swedish waters. The spawning takes place during the period May - August (occasionally spawning specimens could be found in Mars or September). The cod requires a salinity of at least 11 PSU and an oxygen content of at least 2 ml/l (Nissling, 1995) for the spawning to be successful. The population shows great fluctuations and has decreased dramatically during the period 1984-1993. Cod fishing for human consumption is economically important. Cod is among the 'first choice species' recommended within the JAMP (Joint Assessment and Monitoring Programme) and BMP (Baltic Monitoring Programme). Cod liver tissue is used for all determinants except mercury for which muscle tissue is used. The cod liver is fat and organic contaminants are often found in relatively high concentrations. For that reason, it is also a very appropriate matrix for screening for 'new' contaminants. Cod is collected in the autumn from two sites: south east of Gotland and from Fladen at the Swedish west coast. Cod liver tissue samples are analysed for lead, cadmium, copper and zinc as well as for organochlorines. 1995 analyses of chromium and nickel were added. Cod muscle tissue is analysed for mercury. The cod specimens are age determined by otoliths. Specimens of both sexes, between 3-4 years from Gotland and between 2-4 years from Fladen, are analysed.

Anon (2000) Comments Concerning the National Swedish Contaminant Monitoring Programme in Marine Biota. Contaminant Research Group at the Swedish Museum of Natural History., Compiled by Anders Bignert

Geological Survey of Sweden
Villavägen 18
Uppsala

SE-751 28
Sweden