|Long-term and recent changes in the benthic macrofauna living on tidal flats in the western part of the Wadden Sea|
Beukema, J.J. (1992). Long-term and recent changes in the benthic macrofauna living on tidal flats in the western part of the Wadden Sea. Publ. Ser. Neth. Inst. Sea Res. 20: 135-141
In: Publication Series. Netherlands Institute for Sea Research (NIOZ). NIOZ: Den Burg. ISSN 0923-330X, more
|Also published as |
- Beukema, J.J. (1992). Long-term and recent changes in the benthic macrofauna living on tidal flats in the western part of the Wadden Sea, in: Dankers, N.M.J.A. et al. (Ed.) Present and Future Conservation of the Wadden Sea: Proceedings of the 7th International Wadden Sea Symposium, Ameland 1990. 20: pp. 135-141, more
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|Document type: Conference paper|
The bottom fauna living on tidal flats in the westernmost part of the Wadden Sea were followed quantitatively by biannual sampling at 15 fixed stations throughout the 1970-1990 period. During this period, the following long-term changes were observed: 1. Biomass doubled and numerical abundance more than doubled; as a consequence the size of a 'mean' macrobenthic animal declined; 2. The abundance of more than half of the species studied increased significantly; 3. among these species, small deposit-feeding worms were over-represented and some species increased more than other species. The above changes are attributed to the recent eutrophication of the area (Cadée 1992). 4. Favourable effect is the enhanced stock and productivity of the benthos. Detrimental effects ( caused by prolonged periods of oxygen depletion) occurred incidentally and locally. Recent (1988-1990) changes include a marked increase in the species which are known to be sensitive to low winter temperatures and are ascribed to the mild character of the last three winters. The stock of mussels declined during 1990 to unprecedentedly low levels. All intertidal mussel beds were completely destroyed by commercial fishermen to stock their subtidal plots. It is recommended that extensive tidal-flat areas should be closed for such fishery activities.