Ruimtelijke verschillen en temporele fluctuaties in het voorkomen van een aantal schelpdieren in de Voordelta
Craeymeersch, J.A.; Wijsman, J.W.M. (2006). Ruimtelijke verschillen en temporele fluctuaties in het voorkomen van een aantal schelpdieren in de Voordelta. IMARES Wageningen Report, C013/06. Wageningen UR. IMARES: IJmuiden. 29 pp. Part of: IMARES Wageningen Report. Wageningen UR. IMARES: IJmuiden, more |
| Abstract | A marine reserve is planned in the Voordelta to compensate for the loss of nature due to the construction of the second Maasvlakte (MVII). In order to evaluate the effect of this compensation, a monitoring and evaluation programme has been started (MEP-MV2). As part of this programme, a base-line monitoring for macrobenthos has been conducted in 2004 and 2005 in the area where the marine reserve is planned, the location where MVII is planned and in two reference areas. The study presented in this report is part of the base-line monitoring programme. The major goal of this study was to evaluate the spatial and temporal differences in macrofauna abundance between the marine reserve area and the reference areas. Historical data (1993-2004) on 5 shellfish species that are a potential food source for birds in the Voordelta have been analysed. The Voordelta area is characterised by large differences in environmental conditions. Especially the area in front of the Haringvliet (MOND) accommodates a specific macrobenthos community. Cockles are almost explicitly found in this area of the Voordelta, while other species are rarely found. This difference between the area MOND and the other areas within the Voordelta has been confirmed by the present study. The other areas show similar patterns in both in average biomass and density, as well as the historical patterns. Differences can be found between the Southern reference area and the two search areas for the marine reserve (ZRA and ZRB). The average density of Spisula subtruncata is higher in the search areas. Also the trends in both density as biomass of the other shellfish species observed in the search areas differ in the from the trends observed in the other areas. It is concluded that the autonomous developments within the Southern reference area differ from the developments within the marine reserve areas. It would be better if the reference area will be located within the same outer delta as the marine reserve area. The feasibility of this depends on the dimensions and the location of the reserve area. Due to the specific macrobenthos community in front of the Haringvliet, this area cannot be used as a reference area. |
| Dataset | - WOT monitoring shellfish stocks : coastal zone, more
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