Nereocystis luetkeana microsatellite data (Genepop format)

In temperate regions, one of the most critical determinants of present
range-wide genetic diversity was the Pleistocene climate oscillations, the
most recent one created by the last glacial maximum (LGM). This study
aimed to describe Nereocystis luetkeana genetic structure across
its entire range (Alaska to California) and test different models of
population connectivity within the Salish Sea. This region was colonized
after the LGM and has been under increased disturbance in recent decades.
We utilized microsatellite markers to study N.
luetkeana genetic diversity at 53 sites across its
range. Using higher sampling density in the Salish Sea, we employed a
seascape genetics approach and tested isolation by hydrodynamic transport
and environment models. At the species distribution scale, we found four
main groups of genetic co-ancestry, Alaska; Washington with Vancouver
Island's outer coast and Juan de Fuca Strait; Washington's inner
Salish Sea; and Oregon with California. The highest allelic richness (AR)
levels were found in California, near the trailing range edge, although AR
was also high in Alaska. The inner Salish Sea region had the poorest
diversity across the species distribution. Nevertheless, a pattern of
isolation by hydrodynamic transport and environment was supported in this
region. The levels of allelic richness and genetic differentiation suggest
that during the LGM, bull kelp had both northern and southern glacial
refugia in Haida Gwaii and Central California, respectively. Genetic
diversity in Northern California sites seems resilient to recent
disturbances, whereas the low levels of genetic diversity in the inner
Salish Sea are concerning.