The biology and feeding ecology of Arctic charr in the Kerguelen Islands

• Published in: Journal of Fish Biology
• Main Authors: Eldøy, Sindre, Davidsen, Jan, Vignon, Matthias, Power, Michael
• Other Authors: NTNU University Museum Trondheim, Norwegian University of Science and Technology Trondheim (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Ecologie Comportementale et Biologie des Populations de Poissons (ECOBIOP), Université de Pau et des Pays de l'Adour (UPPA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Department of Biology Waterloo, University of Waterloo Waterloo, Natural Sciences and Engineering Research Council of Canada, NTNU University Museum, French Polar Institute (IPEV, Institut Polaire Paul-Emile Victor) as a part of the SALMEVOL and LTSER programs
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDV.BA]Life Sciences [q-bio]/Animal biology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; Antarctic; Arctic; Kerguelen; Kerguelen Islands; Lac des Fougères; Antarc*; Arctic charr; Climate change; Salvelinus alpinus
• Online Access: https://hal.inrae.fr/hal-03102144; https://doi.org/10.1111/jfb.14596

International audience Subsequent to their introduction in the 1950s, Arctic charr Salvelinus alpinus have been able to establish a self‐sustaining population that has adapted to the unique conditions of the sub‐Antarctic Kerguelen Islands. Here, 48 individuals (198–415 mm) were caught with gillnets and their basic biology and feeding ecology were examined using stable isotope analysis. The Lac des Fougères population split use of littoral and pelagic resources evenly, although larger fish relied more heavily on littoral production and appear to follow the size‐dependent life history habitat template seen in many Scandinavian lakes where smaller sized individuals occupy the pelagic zone and larger individuals dominate the littoral habitat. In Kerguelen, Arctic charr mature at the same ages (5.6 years) as Arctic charr in both sub‐Arctic and Arctic lakes. Although mortality was average in comparison to comparator sub‐Arctic lakes, it was high in comparison to Arctic lakes. Maximal age (>7+) was at the lower end of the range typically seen in sub‐Arctic lakes. Although they inhabit a resource‐poor environment, Kerguelen Arctic charr showed no evidence of cannibalism. Thus, while Arctic charr can survive and reproduce in the relatively unproductive Kerguelen lake environments, survival and growth nevertheless appear to be traded off against survival and longevity. The uniqueness of the population location and the recency of its introduction suggest that further monitoring of the population has the potential to yield valuable insights into both the adaptability of the species and its likely responses to ongoing large‐scale environmental change as represented by climate change