Genetic diversity of a marine foundation species, Laminaria hyperborea (Phaeophyceae Laminariales), along the coast of Ireland

Author ORCID

Stacy Krueger-Hadfield 0000-0002-7324-7448

Kathryn Schoenrock 0000-0002-0407-3173

Publication Date

12-8-2020

Abstract

Worldwide, kelp populations are stressed by warming, increased storms and other man-driven disturbances. Marine population distributions are projected to retreat poleward with climate change if they cannot adapt to changing conditions, which would potentially lead to a regime shift in subtidal habitats. In Northern Europe, Laminaria hyperboreais a subtidal ecosystem engineer whose distribution has shifted over millennia, leaving predicted areas of high genetic diversity from the last glacial maximum (LGM) near its southern distribution limit in the Iberian Peninsula. In Ireland, L. hyperborea structures communities by supporting diverse faunal assemblages and producing large quantities of organic carbon throughout the year. We investigated the genetic diversity of eight populations ranging from the southern coast to the northwest of Ireland using nine microsatellite loci. Diversity was found to be highest in Lough Hyne, a Special Area of Conservation (SAC), near the predicted climate refugium. We found evidence of isolation by distance, with high connectivity between populations that were geographically close, likely driven by short range dispersal of L. hyperboreapropagules. Genetic diversity (measured as expected heterozygosity and allelic richness) was highest at Lough Hyne, and decreased northwards, as predicted from past range shifts. Expected heterozygosity was highest at Lough Hyne (0.706) and decreased northward, with the lowest value at Bridges of Ross (0.283). Based on these patterns, further fine-scale investigation into population diversity, dispersal and potential resilience in Irish kelp forests are necessary as warming and non-native species are observed more and more frequently.

Keywords

Boreal, climate refugia, kelp, species distribution

Repository

Dryad

Distribution License

CC0 1.0 Universal - No copyright; this work is in the public domain

Link to Full Text

Share

COinS