Long-term evolution of anadromy in the introduced brown trout (Salmo truttaL.) and its impact on invasion dynamics in the Kerguelen Islands

• Main Authors: Aulus Giacosa, Lucie, Gaudin, Philippe, Vignon, Matthias
• Other Authors: Ecologie Comportementale et Biologie des Populations de Poissons (ECOBIOP), Institut National de la Recherche Agronomique (INRA)-Université de Pau et des Pays de l'Adour (UPPA)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2018
• Subjects: sea trout; introduced species; salmo trutta; espèce introduite; trait de vie; évolution spatiotemporelle; kerguelen; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Antarctic; Kerguelen; Kerguelen Islands; Antarc*
• Online Access: https://hal.science/hal-02154572

International audience In a context of global change, biological invasions are one of the main causes of biodiversity loss. Non-­native species can disperse naturally but the rate of dispersion has increased during the last decades through anthropogenic and natural introductions. In both cases, organisms can adapt or move to be resilient to the global warming, leading to the colonization of new habitat. The study of colonization is of major interest to manage appropriately their invasiveness, to understand their response to global warming and to conserve natural biodiversity.As a consequence of ice retreat in the highest latitude, newly opened rivers could become welcoming habitats for the establishment of colonizing fish. Thus, temperate species will be expected to move to higher latitudes. Salmonids are thought to be good candidates for colonizing such environments since they generally display intrinsic ability to become invasive.Because of its unique characteristics, invasion by the Brown trout (Salmo trutta L.) in sub-­Antarctic Kerguelen Islands represents a good model to improve our knowledge in fish population dynamics in a post­-glacial invasion context. This facultative anadromous iteroparous species shows various life history strategies patterns and is characterized by high phenotypic plasticity where migration plays a significant role in the spatial dynamics of populations. Introduced in the 1950s in a dozen freshwater systems originally deprived of any fish species, the species colonized more than thirty streams in only ten generations. Thanks to long­term monitoring, our data would shed light on the future of polar regions where,because of ice melting, fish­free ecosystems become increasingly accessible to invasion by fish species