In the period from 27-01-2002 until 18-03-2002 126 samples, totalling an area of 6139.58 m2, on different substrates (Zostera, Tidal pool, Sand, Gully Zostera and Gully Cvmodocea) were collected with a Beam trawl in the Baie d'Aouatif, located in the Parc National du Banc d'Arguin, Mauritania. This was done to test the hypothesis that the Banc d'Arguin has an ecological function as a nursery for juvenile fish. 347 individuals of 25 different species were caught, 2 of those species belonged to the class of Cephalopoda. Of the twenty-three fish species, those species belonging to the family of Gobiidae and the Sub-family Syngnathinae were the most common species.