Sampling description

Methods: The sampling unit was the fish haul defined by: a site (station), a date (survey), the fishing gear used. After each fishing haul, all the individuals captured (fish, crustaceans, molluscs) were identified, if possible at the species level. All the individuals captured in the same haul and belonging to the same species were counted.

Sampling: Each geographical entity studied was considered as an ecosystem. In each ecosystem, a number of sampling sites was defined. Data collection consisted of several fishing surveys using one or several fishing gears. The most frequently used fishing gear (58% of occurrences) was a purse seine. It was 250 m long, 18 m deep with a 14 mm mesh size. The purse seine was used blindly, without searching for fish in the defined sampling sites. Other types of fishing gear were used: fyke nets (22.6% of occurrences) to sample juvenile fish, gill nets (12%) in Guinea (in addition to purse seine), Mali and the Urok islands MPA, trawl (5.7%) in the deepest area of the Ebrié lagoon and beach seines (1.6%) in the Sine Saloum and the Bijagos.