|Het effect van baggerwerkzaamheden t.b.v. de verruiming op de kokkelbestanden in de Westerschelde|
Wijsman, J.W.M.; Kesteloo, J.J. (2007). Het effect van baggerwerkzaamheden t.b.v. de verruiming op de kokkelbestanden in de Westerschelde. IMARES Wageningen Report, C081/07. Wageningen UR. IMARES: Wageningen. 35 pp.
Part of: IMARES Wageningen Report. Wageningen UR. IMARES: IJmuiden, more
Dredging; Cardiidae Lamarck, 1809 [WoRMS]; ANE, Netherlands, Westerschelde [Marine Regions]; Brackish water; Fresh water
This study is part of the Environmental Impact Assessment (EIA) on the dredging activities in the Westerschelde.In this study the impact of two dredging and dumping scenarios on the cockle stocks are compared to the zero6alternative (continuation of the present situation). The calculations have been done for the short term (2010) andmidterm (2015). The study shows that the impact on the total cockle stocks is minor. It is expected that thepotential for the cockle stocks in 2010 will be decreased by 0.2% to 0.3% compared to the zero alternative. For2015 an increase in potential for cockle stocks of 0.4% to 3% is expected. These expected changes are minorcompared to the natural year to year fluctuations of the cockle stocks in the Westerschelde (coefficient ofvariation ≈ 0.6).The potential cockle stocks are calculated based on the expected changes in ecotope types. The analysis showsthat the present ecotope classification is a fairly good indicator for the average cockle biomass at a specificlocation. The highest cockle biomass in general occurs at the intermediate and lower parts of the intertidal flatswith low dynamics. Cockles are almost absent in the eastern part of the Westerschelde due to the low salineconditions in this area.