Impact of the Trammel Net in Martinique Fishery, F.W.I. 2010

Small scale fisheries in Martinique are an important social and economic sector. Fisheries management is a local priority concern to limit coastal resources decline. The net fishery accounts for 20% of the fishing techniques used and causes serious ecological problems as well as for species selectivity. Among the gears used, the trammel net (bottom net) is the most problematic technique. Experimental fishing, targeting lobster (26 trials) and fish (21 trials), was conducted to determine the impact of these techniques. For the fish techniques, the trammel net caused 68% of bycatch (0.41 g.100m/h) (non commercial, undersize commercial and rotten individuals). The non-commercial species represented most of the catches (59%). The lobster fishing showed that trammel net is more selective with 22% of discards. The lobster counted for 47% (0.63 g.100m/h). The other 53% catches are crabs, finfishes and rays. To assess the impact of trammel nets on benthic communities, 4 “cleanness” classes have been determined. The benthic species and debris catches (algae, coral, rock, seagrass) in the nets have been estimated to cover 63% (mean value) of the net surface (visual estimation). Trammel nets have a significant impact on benthic coral communities. Among the major problems caused by these three layers net, bycatches of protected species is a reality difficult to assess. Fifteen marine turtles have been caught, and 73% were dead by drowning. A policy (ban, no fishing area, fishing period…) in order to limit the impact of trammel nets is required for more sustainable small scale fisheries.