Consequences of the Sudden Removal of Nearly All Mussels and Cockles from the Dutch Wadden Sea

摘要: . Three successive years of recruitment failure, intensive fishery, and high rates natural mortality eliminated all intertidal mussel beds nearly cockle from the Dutch Wadden Sea in course 1990. In late 1990 early 1991, zoobenthic biomass particularly bivalve stocks were unprecedentedly low. The following unusual events noted: 1) Relatively diatom chlorophyll concentrations autumn an exceptionally dense spring bloom diatoms March 1991; 2) Exceptionally onset rapid growth Macoma balthica 1991; 3) Above-average weights soft parts bivalves 1990/91 winter; 4) Elevated that could serve as alternative prey for birds specialised on big (oystercatchers eiders); 5) Signs food shortage such birds: emigration to other feeding areas; 6) A recovery benthos started summer accelerated by some affected species. It is concluded ecosystem responded elastic way removal two its key species. are not seen merely coincidental but regarded a chain causes effects.