THE FUNCTIONING OF THE ECOSYSTEM OF THE BANC-DARGUIN, MAURITANIA - A REVIEW

The Banc d'Arguin, Mauritania, is an area of over 10000 km2 of shallow water and tidal flats between the Sahara and the upwelling system off the Mauritanian coast. The results of the Dutch-Mauritanian project ' Banc d'Arguin 1988' as well as the relevant literature are reviewed in order to develop a preliminary conceptual model of the functioning of this ecosystem. Hydrographically the Banc d'Arguin can be characteriz ed as a large-scale negative estuary with higher salinities near the s hore. It is concluded that ultimately the Banc d'Arguin ecosystem is f ueled by nutrients and organic matter derived from the upwelling area. The inner part of the Banc d'Arguin system is dominated by a detritus -based benthic foodweb in which seagrasses are the principal primary p roducers. Little of the seagrass production seems to be exported to ot her parts of the system or other areas. Zooplankton and zoobenthos bio masses are relatively low, but nevertheless support high densities of consumers. Aquatic birds are especially numerous. The study identifies many research topics for the future.