Monitoring schelpdier-bestanden - WOT-05-001-008

As a basis for the Dutch fisheries policy, the quantities, spatial distribution and composition of a number of shellfish stocks in Dutch coastal waters and estuaries are monitored through stock surveys.

The policy for the management of shellfish stocks in Dutch coastal marine waters is presently based on an integration of fishery-related and ecological objectives. Major elements of management are closed areas, catch quotas and considerations on nutrition needs for birds. Fishing of mussels in tidal areas is only permitted when at least 2000 ha of mussel beds are present.

Furthermore, management of the bivalve stocks in the Wadden Sea takes into account the agreements of the Trilateral Governmental Conference on the Protection of the Wadden Sea .
project: The major elements of the programme are an assessment of the intertidal area covered by beds of blue mussels (Mytilus edulis) and Pacific oysters (Crassostrea gigas) in the Wadden Sea, Oosterschelde bay and Westerschelde estuary, of the intertidal stocks of blue mussels, Pacific oysters and cockles (Cesrastoderma edule) in the Wadden Sea, Oosterschelde bay and Westerschelde estuary, of the stocks of American jackknife (Ensis sp.), cut through shell (Spisula subtruncata) and other commercially relevant species in the Dutch coastal zone of the North Sea, of the stocks of mussels, oysters, cockles and other shellfish species in the lakes Veerse Meer and Grevelingenmeer, and of the stock of American jackknife in the subtidal of the western Dutch Wadden Sea.

The assessments in all different areas are carried out using research vessels and chartered vessel, and in close cooperation with fisheries inspectors.
The North Sea survey also monitors other benthos species and is part of a time series which indicates considerable changes in the benthic fauna over the period the survey has been carried out.