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

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 re...