Responses of bottom invertebrates to pollution in the Arctic: bioassays with blue mussel Mylilus edulis L

Environmental control in the Arctic ecosystems needs to be changed to hi-tech monitoring technologies with IT systems for actual and ecologically effective 'arctic safeguard'. In circumstances of the fragile arctic ecosystems, priority bioassay of possible toxic hazards in natural seawater must be undertaken. It was considered useful to examine toxic responses of some indicator species. Bivalves are well-known indicators of pollution stress arising from the activities of man, such as off-shore drilling and oil transportation, dredging or the release of pollutants. Toxic effects of some drilling fluids on energy balance, behavior and survival of the common mussel Mytilus edulis L, were estimated in long-duration bioassays of about 30 days each. The highest sensitivity of behavioral responses to any changes in chemical water composition was found. Mussels of the Barents Sea had significant differences from the control by four behavioral parameters even at 0.01 g/l of the ferrochrome-lignosulfonate drilling fluid, while the significant differences from the control in oxygen consumption and filtration rates were observed only at the 10 g/l. Even small concentration of another standard water-based drilling fluid with barite (of about 0.05 g/l) had a lethal effect on M. edulis .