Data from: Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic

Climate changes in the Arctic are predicted to alter distributions of
marine species. However, such changes are difficult to quantify because
information on present species distribution and the genetic variation
within species is lacking or poorly examined. Blue mussels, Mytilus spp.
are ecosystem engineers in the coastal zone globally. In order to improve
knowledge of distribution and genetic structure of the Mytilus edulis
complex in the Arctic, we analyzed 81 SNPs in 534 Mytilus spp. individuals
sampled at 13 sites to provide baseline data for distribution and genetic
variation of Mytilus mussels in the European Arctic. Mytilus edulis was
the most abundant species found with a clear genetic split between
populations in Greenland and the Eastern Atlantic. Surprisingly, analyses
revealed the presence of M. trossulus in high Arctic NW Greenland (77°N)
and M. galloprovincialis or their hybrids in SW Greenland, Svalbard and
the Pechora Sea. Furthermore, a high degree of hybridization and
introgression between species was observed. Our study highlights the
importance of distinguishing between congener species, which can display
local adaptation and suggests that information on dispersal routes and
barriers are essential for accurate predictions of regional susceptibility
to range expansions or invasions of boreal species in the Arctic.