Role Of Filter Feeders Research Articles

The Effect of Synthetic Surfactants on the Hydrobiological Mechanisms of Water Self-Purification

Long-term studies of the biological effect of surfactants, including the effect surfactants exert on filter feeders, are reviewed. The role of filter feeders in the functioning of freshwater and marine ecosystems is analyzed. New aspects in the assessment of environmental hazard due to the impact of chemical pollutants, including surfactants and detergents, are established.

Water Quality Improvements in Liverpool Docks: The Role of Filter Feeders in Algal and Nutrient Dynamics

Abstract. The redevelopment of disused docks around Liverpool into areas suitable for shops, offices, housing and recreational watersports has necessitated the maintenance of good water quality in these areas. The main source of water to the docks is the River Mersey, which contains high concentrations of nutrients, encouraging algal blooms ‐ including potentially nuisance species ‐ in the enclosed dock basins. Since 1988 an extensive monitoring programme has been run sampling the hydrography, plankton and benthos of the docks. During this period there has been an improvement in water quality, including a reduction in summer phytoplankton biomass and anoxic bottom water. There are strong indications that phytoplankton biomass has been severely reduced by the filter feeding of Mytifus edulis. Changes in the composition of the benthic community since 1988 suggest that the large population of M. edulis is now suffering from limited recruitment. The long‐term development and stability of the system is discussed with reference to community succession and its link to ecosystem functioning.

The contribution of Mytilus sp. in radionuclide transfer between water column and sediments in the estuarine and delta systems of the Rhône river

The fate of three radionuclides (3H, 137Cs, 106Ru) has been studied in the spreading area of the Rhone river and the nearby Gulf of Fos. The role of filter-feeders such as Mytilus sp., in this fate was investigated by periodically sampling the water column, molluscs and underlying sediments during 1986 and 1987. Results show that radionuclides may be a valuable tracer for Rhone river effluents entering the coastal area either in sediments or in the flesh of filter feeders. For example, tritium levels in the organic matter of superficial sediment decreases from the river mouth (3113 Bq l−13H of combustion water) to more offshore areas (219 Bq l−13H). This phenomenon is related to the settling characteristics of suspended matter in such areas. In areas with high biological activity, the role of filter feeders seems to dominate the transfer of radionuclides from the water column to the bottom, due to concentration of these elements in biodeposits. Deposition rates ranged from 13–50 Bq m−2 d−1 137Cs for September and May respectively. This transfer undergoes temporal fluctuations correlated with seasonal variations of the main hydrobiological parameters.

A Possible Mechanism for Maintaining Diversity in Species-Rich Communities: An Addendum to Connell's Hypotheses

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