Origin and route of establishment of the invasive Pacific oyster Crassostrea gigas in Scandinavia

• Published in: Marine Ecology Progress Series
• Main Authors: Faust, Ellika, Andre, Carl, Meurling, Sara, Kochmann, Judith, Christiansen, Henrik, Jensen, Lasse Fast, Charrier, Grégory, Laugen, Ane T., Strand, Asa
• Other Authors: Department of Marine Sciences Gothenburg, University of Gothenburg (GU), Department of Ecology and Genetics Uppsala (EBC), Uppsala University, Senckenberg – Leibniz Institution for Biodiversity and Earth System Research - Senckenberg Gesellschaft für Naturforschung, Leibniz Association, Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Goethe-Universität Frankfurt am Main-Senckenberg – Leibniz Institution for Biodiversity and Earth System Research - Senckenberg Gesellschaft für Naturforschung, Leibniz Association-Leibniz Association, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO), Swedish University of Agricultural Sciences (SLU)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: ACL; Microsatellites; population-structure; connectivity; Adaptation; aquaculture; biological invasions; differentiation; genetic drift; introductions; markers; microsatellite; Non-native species; nonnative oysters; Population genetics; Range expansion; Scandinavia; skagerrak; software; envir; geo; Norway; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://doi.org/10.3354/meps12219; https://hal.archives-ouvertes.fr/hal-02572873/file/Faust_etal_MEPS_2017.pdf; https://hal.archives-ouvertes.fr/hal-02572873

WOS:000406135500008 International audience Identifying the routes and rates of introductions is fundamental for the understanding of marine invasions. Recurring introductions over the last 50 yr have led to the establishment of feral Pacific oyster Crassostrea gigas populations throughout Europe. In the northern countries, Sweden and Norway, the species first occurred in large numbers in 2006. Here, we investigated the relative importance of introduction via re-laying of cultured oysters imported for consumption from France, Ireland or the Netherlands, and dispersal of oyster larvae by ocean currents from wild oyster populations in Denmark. Using microsatellite DNA markers, we estimated genetic differentiation among Pacific oysters collected at 4 Swedish locations, 3 Norwegian locations and 9 potential source locations in Denmark, Ireland, the Netherlands and France. All Swedish samples and 1 Norwegian sample(Tromlingene) were genetically similar to each other and the Danish samples and showed significant genetic differentiation from all other populations. Consequently, it appears that the Pacific oyster populations in Sweden, Denmark and Tromlingene are closely connected and/or share a recent origin. The 2 remaining Norwegian samples(Hui and Espevik) differed from each other and all other populations, but showed similarities to wild oyster samples from Scandinavia and Ireland, respectively. Overall, the results underline a complex origin of Norwegian oysters, with gene flow from Swedish/Danish populations, as well as other unidentified sources. The apparent connectivity among most of the Scandinavian populations has implications for regional management of this invasive species, and highlights possible scenarios for other marine invasive species with a similar life history.