A Biological Valuation Map for the Belgian Continental Shelf
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picture: F. Rendant
The continuously increasing socio-economical interest in marine resources urges the need for a decision making framework to objectively allocate the different user functions at the Belgian Continental Shelf (BCS). This calls for a spatial structure plan, preferentially firmly based on the concept of integrated marine management, in which biological value should be carefully taken into account. Unfortunately, so far an integrated view on the biological value of the BCS is lacking. A first attempt to assess the biological value of (parts of) the BCS exists, but this study only took into account one ecosystem component (i.e. macrobenthos) and non-extrapolated to the whole shelf, generally failing to provide an integrated, full-coverage Biological Valuation Map of the BCS.


Several methods for biological valuation in the marine environment or site selection criteria for the installation of nature protection areas (Bird/Habitat Directive areas, MPAs, Ramsar areas,...) already exist. To be able to set up an objective valuation strategy a review of all available methods/criteria, described in the literature will be carried out. In an early phase of the project two workshops will be held to develop this valuation strategy. Since there already exists a BVM for the terrestrial part of Belgium, the methodology used to develop this map and lessons learned during this development will be discussed during a first national workshop. Because there are fundamental differences in the structure and functioning of terrestrial and marine environments, adaptations to the terrestrial methodology will be needed. To assist in this adaptation a second international expert workshop will be held to discuss the results of the national workshop and the review of existing marine valuation methods. Experts will be chosen on the basis of their expertise in different marine ecosystems. These workshops should lead to the development of a scientifically acceptable and widely applicable marine valuation strategy.

The marine Biological Valuation Map should include and integrate information on all marine ecosystem components for which detailed spatial distribution data are available. At the Belgian Continental Shelf such data are primarily available for the macrobenthos and seabirds (macrobenthos: UGent-MACRODAT database; seabirds: IN database). To a lesser extent, but still useful from a valuing perspective, data on the spatial distribution of the epi- and hyperbenthos exist (UGent and DVZ databases). It was decided to base the biological valuation of the Belgian Continental Shelf on the spatial distribution of seabirds and macrobenthos (full coverage baseline Biological Valuation Map), while epi- and hyperbenthos data will be used as an upgrade (upgraded Biological Valuation Map for selected areas).

The seabird database consists of a set of points where densities are known. In order to cover the entire Belgian marine area a GIS-aided inter- and extrapolation will be performed. Contrary to avifauna data, in which direct observations almost provide full-coverage information for numerous areas at the Belgian Continental Shelf, benthos data should be regarded as point data. To spatially extrapolate these point data, needed to obtain a full coverage spatial distribution map, a predictive model, based on the close link between the macrobenthos and its physical habitat, will be set up. Once developed and validated, the model will enable to extrapolate the spatial distribution of the macrobenthos to the full Belgian Continental Shelf, using existing data on the physical habitat (GIS-aided).
Even though large databases on seabirds are available, there are still areas at the Belgian Continental Shelf (mainly the outer parts) with a poor coverage of data. Supplementary seabird counts will fill the gap in these areas. New samples on macrobenthos will be collected to ground-truth the predicted full-coverage distribution maps.

picture adjusted and taken from following publication: Maes, F.; Cliquet, A.; Seys, J.; Meire, P.; Offringa, H. (2000). Limited atlas of the Belgian part of the North Sea. Federal Office for Scientific, Technical and Cultural Affairs: Brussel, Belgium. 31 pp.

Once a full coverage map of the spatial distribution of macrobenthos and seabirds is generated, these maps will be evaluated according to the set valueing criteria. Through a GIS aided combination of the different valuation maps (macrobenthos-seabirds and criteria) a full coverage base Biological Valuation Map will be attained. This baseline Biological Valuation Map will further be upgraded using data on the epi- and hyperbenthic value, within areas were information on these components is available (upgraded Biological Valuation Map for selected areas).

Expected results

The marine BVM is an indispensable tool to obtain an objective and scientifically-sound spatial structure plan of the BCS. Next to the above mentioned exploitation of the final result of BWZee, other results are:

  1. an integrated databases on the biology and physical environment of the BCS

    basic knowledge for future research
  1. the innovative approach to set up a marine BVM (e.g. valuation criteria)

    baseline for future international marine valuation
  1. the development of the predictive model

    an efficient querring of seafloor data related to the BCS

    a better understanding of factors and processes structuring the distribution of marine habitats

    contribution to the set up of future integrated monitoring strategies
  1. full coverage information on the spatial distribution of macrobenthos and seabirds

    improved understanding of the ecosystem structure of the BCS
  1. the translation of results and conclusions for the benefit of scientists, managers, policy makers, the public at large (also attention for educational aspect).

    general background information on BWZee

    increase in public awareness in marine biological value (interactive website)

Supported by
the Belgian Federal Science Policy Office

General coordination: Magda Vincx, Steven Degraer
Web site and databases hosted by VLIZ
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