THE INFLUENCE OF MUSSEL BEDS ON NUTRIENTS IN THE WESTERN WADDEN SEA AND EASTERN SCHELDT ESTUARIES

The uptake and release of materials by intertidal mussel beds were directly measured in two cultivated Dutch estuaries. Generally, chlorophyll a, seston, and particulate organic carbon were taken up, while ammonium, orthophosphate, and silicate were released. The observed rates were higher than values computed from organismic observations and similar to those observed for intertidal oyster reefs in South Carolina. Specific estuarine material turnover rates varied from 1 week to 38 weeks when calculated with mussel bed fluxes. The fastest turnover rates were for chlorophyll a and ammonium. These results support the idea that dense assemblages of bivalves are major components in the recycling of nutrients in estuaries.