Changes in the brown shrimp (Crangon crangon L.) population off the Dutch coast in relation to fisheries and phosphate discharge

Abstract

Significant changes have occurred in the distribution pattern and recruitment success of brown shrimp (Crangon crangon L.) off the Dutch coast and in the fishery for this species between the period 1980-1984 and 1991- 1994. The fundamental cause of these changes appears to be the reduction in phosphate discharge to this area, mainly by the river Rhine, which reached a peak in the early 1980s and decreased considerably after 1984. More pronounced changes in the brown shrimp stock have occurred along the Dutch west coast than along the north coast, which is probably related to higher nutrient concentrations on the west coast and the stronger effect of changes in phosphate discharge in this area.