Indicateurs du niveau de présence de l'anguille européenne (A. anguilla) dans le Marais poitevin : bilan des campagnes 2002-2006 Etude Cemagref Bordeaux, n° 107

• Main Authors: Rigaud, Christian, Roqueplo, Charles, Le Barh, Romaric, Rey, Sebastien, Longis, T.
• Other Authors: Ecosystèmes estuariens et poissons migrateurs amphihalins (UR EPBX), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), irstea
• Format: Report
• Language: French
• Published: HAL CCSD 2006
• Subjects: [SDE]Environmental Sciences; le Marais; European eel
• Online Access: https://hal.inrae.fr/hal-02588588

From 2002 to 2006, standardized electrofishing operations have been performed in May on two pools of 8 permanent sites located on the secondary hydraulic network of the Marais poitevin. Four campaigns have concerned the first pool, the second one being sampled only in 2005. 21 species have been observed with significant differences between areas and between years. The European eel is present everywhere and is one the most abundant species in this marsh. Except for the small eels (up to 100 mm), the mean fishing effectiveness is good (more than 83 %) during all the campaigns. The mean eel abundance levels (16 to 26 eels /100 m²) and the observed size structures are homogeneous between the campaigns with more than 90% of the captures with an individual total length less than 420 mm. These data concerning the various size groups set up a reference basis to evaluate the impacts of future management actions to significantly increase the recruitment level of young eels in the marsh and the survival rate up to the breeder stage (silver eel). A local plan for the eel management appears actually necessary. Its goals will have to be not only the significant restoration of the young eels' stock, but also the significant increase of the breeder escapement level to contribute to the restoration of the eel stock common to the majority of the European and North-african waters. This local plan will have to take into account all the factors of mortality or perturbation (obstacles to free migrations, water quality, availability of the habitats, all the fishing procedures, .). De 2002 à 2006, des opérations standardisées de pêche électrique ont été réalisées en mai sur deux groupes de 8 stations fixes situées sur le réseau hydraulique secondaire du marais. Quatre campagnes ont été mises en ½uvre sur le premier réseau, le second réseau n'ayant été pêché qu'en 2005. 21 espèces ont été recensées avec des différences notables entre zones et entre années. L'anguille apparaît dans toutes les opérations et constitue l'une des espèces ...