RAPID COMMUNICATION / COMMUNICATION RAPIDE Natural recolonization of the Seine River by Atlantic salmon (Salmo salar) of multiple origins

• Main Authors: Charles Perrier, Guillaume Evanno, Rene ́ Guyomard
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.636.663; http://hal-agroparistech.archives-ouvertes.fr/docs/00/58/41/40/PDF/AN2010-PUB00027286.pdf

Abstract: The restoration of previously extinct salmon populations is usually achieved with stocking programmes, but nat-ural recolonization can also occur through the straying of individuals from nearby populations. Here we investigated the origin of Atlantic salmon (Salmo salar) that recently recolonized the Seine River (France). The degradation of this river had led to the extinction of the population, but since the 1990s, the water quality has greatly improved. Although no stock-ing was performed, 162 individual salmon were recently observed by video-counting. Seven fish were sampled for mor-phological and genetic analyses. These individuals were genotyped at 17 microsatellites markers and their probable source populations were identified using baseline samples from regional and distant populations. Four of the sampled individuals were grilse and three were multi-sea-winter fish. Genetic analyses revealed that the fish partly originated from a nearby stock but also from distant populations, suggesting long-distance straying. This natural recolonization of a large river by strayers from several origins is discussed in terms of population sustainability and management. Résume ́ : La restauration de populations antérieurement éradiquées de saumons se fait ordinairement par des programmes d’empoissonnement, mais il peut aussi exister une recolonisation naturelle par les individus errants des populations avoisi-nantes. Nous examinons ici l’origine des saumons atlantiques (Salmo salar) qui ont récemment recolonise ́ la Seine (France). La dégradation du fleuve avait entraı̂ne ́ l’extinction de la population, mais depuis les années 1990, la qualite ́ de l’eau s’est grandement améliorée. Bien qu’aucun empoissonnement n’ait éte ́ effectué, 162 saumons individuels ont récem-