BIOMASS OF MACROBENTHIC TIDAL FLAT FAUNA OF THE BANC-DARGUIN, MAURITANIA

The biomass of the benthic macrofauna of the tidal flats of the Banc d 'Arguin, Mauritania, retained by a sieve of 0.6 mm, has been estimated . The total biomass amounts to about 17.0 g ash-free dry weight (AFDW) m-2 in the area sampled (about 300 km2). The large bivalve Anadara se nilis is responsible for 8.1 g AFDW m-2, over 100 other species for an other 8.9 g m-2. The largest biomasses are found near the continental shore; at the offshore tidal flats benthic filter-feeders are lacking. Seagrass beds, which occupy the larger part of the tidal flats, have an under average biomass. Sebkhas, extremely saline flats above mean h igh-water mark, contain no live animals. To sustain the consumption of benthic prey by the very abundant wintering shorebirds relatively low P/B ratios are sufficient.