There are numerous stocks in the region. Their area was calculated from sedimentological maps; the sea bottoms considered to be shrimping grounds being those located between 20 m and 50 m, whose percentage of fine particles exceeds 75 percent (muddy sand sediments). When maps were not available, the areas estimated by Burukovski and Bulanenkov (1969) have been used. The list of stocks and their areas are given in Table 1; their bathymetric distribution is shown in Figure 1.
The three concentrations off Ivory Coast are considered as one single stock (Garcia, 1976), with similar evolution and variations in the catch rates from 1969 to 1975.
The stocks of Benin, Nigeria and Cameroon have been dealt with as a whole because it was not possible to distinguish the geographical origin of the catches.
