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DOI

  • Nathan King
  • Niall McKeown
    Aberystwyth University
  • Dan Smale
    The Marine Biological Association of the United Kingdom, Plymouth
  • Sunny Bradbury
    Aberystwyth University
  • Thomas Stamp
    Plymouth University
  • Alexander Juterbock
    Nord University, Norway
  • Hrönn Egilsdóttir
    Marine and Freshwater Research Institute, Reykjavik
  • Emily Groves
  • Pippa Moore
    Aberystwyth University
Kelp are foundation species threatened by ongoing warming trends and increased harvesting pressure. This emphasizes the need to study genetic structure over various spatial scales to resolve demographic and genetic processes underpinning resilience. Here, we investigate the genetic diversity in the kelp, Laminaria digitata, in previously understudied southern (trailing-edge) and northern (range-centre) regions in the Northeastern Atlantic Ocean. There was strong hierarchical spatial structuring with significantly lower genetic variability and gene flow among southern populations. As these span the area of the Hurd’s deep Pleistocene glacial refuge, the current low variation likely reflects a fraction of previous levels that has been eroded at the species southern edge. Northern variability and private alleles also indicate contributions from cryptic northern glacial refugia. Contrary to expectations of a positive relationship between neutral genetic diversity and resilience, a previous study reported individuals from the same genetically impoverished southern populations to be better adapted to cope with thermal stress than northern individuals. This not only demonstrates that neutral genetic diversity may be a poor indicator of resilience to environmental stress but also confirms that extirpation of southern populations will result in the loss of evolved, not just potential, adaptations for resilience.
Original languageEnglish
Pages (from-to) 1906–1913
JournalICES Journal of Marine Science
Volume77
Issue number5
Early online date27 May 2020
DOIs
Publication statusPublished - 1 Sep 2020
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