||The oyster farming is widespread at the Benin (West Africa) coastal zone and provides
sustainable revenues for grass-roots. This study assessed environmental conditions, farming
systems, growth, yields and revenues of the cultivated shellfish, Crassostrea gasar. Results
indicated that rearing milieu meets ecological conditions for successful oyster cultivation.
Production stages were seed collection and stocking, oyster spreading, growth control, harvesting
and processing. Mean stocking density of C. gasar recorded in the rearing milieu was 500 oysters
per square meter. Dominant preys consumed by C. gasar at the rearing site were phytoplankton
with volumetric proportions reaching 73%. Final mean total length reached 72.6 ± 5.78 mm
(mean weight = 63.16 ± 18.16 g) corresponding to a mean monthly growth of 3.31 mm- total
length (4.57 g - total weight). Total length – total weight relationships of C. gasar were
significant (p< 0.05) with a positive slope indicating that the weight increase with size. Growth
variations across the three seasons (dry, wet, flood) were significantly different (F2, 10 = 7.156, p
= 0.02). Also, seasonal mortalities were significantly different (F2, 10 = 4.579, p = 0.047) and
higher values were recorded during the flooding season. Oyster farming at the Benin coastal
waters generated an annual yield of 30 kg/m2 with estimated mean yearly revenues of 160,000
FCFA (US$330) per individual. Habitat disturbances such as the destruction of mangroves, input
of anthropogenic contaminants, nutrient enrichment and the hydroelectric dam built on the Mono
River were among the major stressors that could affect the traditional oyster farming. As an
alternative source of revenues, the great establishment of the oyster farming in the Benin coastal
waters may greatly contribute to coastal fish conservation and sustainable fisheries management.
The development of the oyster farming in Benin requires further scientific knowledge in order to
increase productivity and to contribute to restore fish community structure.