Interspecific hybridization between Atlantic salmon and brown trout introduced in the subantarctic Kerguelen Islands

In the subantarctic French territory of the Kerguelen Islands, Atlantic salmon Salmo salar was stocked to create a new population in the Korrigans drainage system. The analysis of historical scale collections showed that hybrids were inadvertently introduced with the original Atlantic salmon stocks. Later colonization of the Korrigans system by brown trout Salmo trutta was followed by interspecific hybridization between the two species. Our results highlight the importance of both routine genetic monitoring of hatchery stocks and considering the possible influence of other species when stocking is envisaged.