Data from: Oceanographic variation influences spatial genomic structure in the sea scallop, Placopecten magellanicus

Environmental factors can influence diversity and population structure in
marine species and accurate understanding of this influence can both
improve fisheries management and help predict responses to environmental
change. We used 7163 SNPs derived from restriction site-associated DNA
sequencing genotyped in 245 individuals of the economically important sea
scallop, Placopecten magellanicus, to evaluate the correlations between
oceanographic variation and a previously identified latitudinal genomic
cline. Sea scallops span a broad latitudinal area (>10 degrees),
and we hypothesized that climatic variation significantly drives clinal
trends in allele frequency. Using a large environmental dataset, including
temperature, salinity, chlorophyll a, and nutrient concentrations, we
identified a suite of SNPs (285–621, depending on analysis and
environmental dataset) potentially under selection through correlations
with environmental variation. Principal components analysis of different
outlier SNPs and environmental datasets revealed similar northern and
southern clusters, with significant associations between the first axes of
each (R2adj = .66–.79). Multivariate redundancy analysis of outlier SNPs
and the environmental principal components indicated that environmental
factors explained more than 32% of the variance. Similarly, multiple
linear regressions and random-forest analysis identified winter average
and minimum ocean temperatures as significant parameters in the link
between genetic and environmental variation. This work indicates that
oceanographic variation is associated with the observed genomic cline in
this species and that seasonal periods of extreme cold may restrict gene
flow along a latitudinal gradient in this marine benthic bivalve.
Incorporating this finding into management may improve accuracy of
management strategies and future predictions.