Captures accidentelles de mammifères marins sur les filets calés en Manche : Observations réalisées dans le cadre de la première année de réalisation du projet FilManCet (Novembre 2008- Octobre 2009)

Up to now there has been no strong investigation on bycatch of marine mammals in the French set net fisheries of the English Channel (ICES areas VIIe,d &IVc) as the EC 812/2004 regulation does not oblige the state members to put observers on board of vessels in the ICES area VII. A study named FilManCet has been started end 2008-beginning 2009 to focus on the bycatch occurring on the set net vessels issued from Boulogne and Dunkerque ports (fisheries in VIId&IVc) and from the ports of North of Brittany. In this study which is conducted by the Fishing Industry, the data are made available to the scientists of Ifremer who has prepared also the sampling scheme for observation at sea. Two observers are employed full time in the North of France coasts by the non-governmental organisation OCEAMM and four observers are employed by the company SINAY. The observation program is carried on for 2 two years At the end of October 2009, a total of 358 fishing days were observed (74 fishing days in area VIId and 214 fishing days were observed in area VIIe. Even if the coverage is not as high as planned, the observations in the North of Brittany (VIIe) are regular, covering all the months between beginning of February and end of October. Three bycatch of cetacean has been recorded in the 1866 km of nets hauled in the French fisheries of the English Channel. Two porpoise and one pilot whale were all captured with vessels less than 12m working in the area 26E5 with nets targeting the monkfish Lophius piscatorius with trammel nets immerged at a depth greater than 90 m. The harbour porpoise Phocoena phocoena (2 animals) were captured in june and in october 2009 and the pilot whale was recorded in October. For the Western Channel, the bycatch rate in set nets resulting was only two porpoise for 214 days at sea having a total of 1437 km of hauled nets . The observed nets were compounded of 1062 km of large mesh nets (monkfish and rays), 270 km of spider crab nets and 105 km of miscellaneous targeted fish. The VIIe investigated area was the fishing area of vessels from Saint-Malo to Morlaix. This bycatch in a part of VIIe where some nets targeting spider crabs are used with long immersion time corresponds to one pilot whale per 160 000 km.h and one porpoise per 80 000 km/h which is 100 times lower than what has been observed on Irish nets in the Celtic Sea and 700 times lower than what has been reported in the North Sea by some authors. Such a low bycatch rate was yet observed in the VIIe area from which includes Paimpol where another observer has observed 160 days at sea between july 2007 and november 2008 with only one bycatch of common dolphin. Other French data yet reported for area VII indicate that a higher bycatch rate of marine mammals including harbour porpoise seems to occur in VIIf areas in 2007 and 2008 summers. All these informations indicate that the bycatch rate in the south of area VIIe is very low compared to other areas as VIIf. Such an information can help to improve the EC 812/2004 regulation.