Guidance Commercial fisheries in the Waddenzee and Zeeland delta

Index Commercial fisheries in Waddenzee and Zeeland Delta

• Sole and plaice in the Waddenzee
• Cockle
• Eider in Waddenzee
• Oystercatcher in Waddenzee
• The common oyster and the Japanese oyster in the Zeeland delta
• The common seal and the grey seal in the Waddenzee and Delta area

The tidal areas are important as spawning areas and nurseries for fish like sole and plaice. In recent years, numbers of plaice have fallen sharply, possibly because of fishing in the Noordzee (North Sea).

Many birds in the tidal area live off the huge numbers of shellfish, which include cockles and mussels. Shellfish numbers fluctuate strongly from year to year; in years when numbers are low, shellfish fishery can negatively affect numbers of birds. In the Waddenzee, oystercatchers and eiders are both suffering from food shortages and are declining. Research is currently being done on the precise reasons for the decline of these two species in the Waddenzee and the role played in this by shellfish fishery.

Oysters are cultured commercially. Numbers of the native flat oyster have crashed, because of disease, but the disease-resistant Japanese oyster, an exotic, has greatly increased in numbers.

Water quality of the Waddenzee and Zeeland delta

The water quality of the Waddenzee and Zeeland delta has improved. Among the species to have profited, particularly in the Waddenzee, are seals and sandwich tern. The improved water quality has also led to a slight improvement in numbers of migratory fish.

References

• Leopold, M.F. en N.M.J.A. Dankers (1997). Natuur in de zoute wateren. IKC Natuurbeheer. Wageningen.