Investigations of exposure levels in fish and bivalves and toxic effects of sediment from the waters of Muskö Naval Base

On commission of the Swedish Armed Forces the Swedish Defence Research Agency (FOI) has investigated the toxic effects of sediment extracts, the amounts of PCB, organic tin compounds and heavy metals in sediment, fish and bivalves (Mytilus edulis and Macoma baltica) and surveyed the environmental impact of these compounds in the waters of Muskö Naval Base. The investigation is a continuation of a study made earlier by FOI and The Geological Survey of Sweden on the pollution of the sediments in the foretunnels at the naval base. Sediment, bivalves and fish were sampled in possible pollution gradients at selected places in Horsfjärden and Mälbyfjärden. Reference samples of sediment and bivalves were taken in the waters close to Svartarsen/Blacken south east of Muskö and of fish in the waters of Bay of Blista north east of Gålön. The toxicity of extracts from sediments was investigated on mouse cells (L929) and on the water flea, Ceriodaphnia dubia. Samples from Lugneviken and south east of Skramsö were toxic to the cells. The extracts were not acute toxic to the water flea. Fish (perch) and sea mussel from Mälbyfjärden and waters nearby had high levels of organic tin compouns. High levels of mercury were found in perch. The sediment in the same area was polluted by organic tin compounds, copper, cadmium and mercury. Critical areas concerning environmental hazards were Lugneviken and adjacent waters receiving water coming through the Skramsösundet (Sound of Skramsö).