Preliminary assessment of genetic diversity in bycatch-caught darkbelly skate (Bathyraja meridionalis) from South Georgia

Reliable species identification and population assessments of skates are crucial for the sustainable management of their vulnerable stocks. However, species identification is a major challenge in skate studies due to convergent morphology within and between genera. In this study, we applied molecular tools to identify specimens of softnose skates (Bathyraja spp.) caught as bycatch from the longline fishery around South Georgia. Mitochondrial DNA Control Region sequence analyses highlighted a discrepancy between previous genetic studies of B. meridionalis and B. maccaini that challenged the identification of our putative B. meridionalis samples. Detailed analyses of Bathyraja data submitted in Genbank lead to the conclusion that our South Georgia samples were likely to be B. meridionalis but further mitochondrial markers are being sequenced to confirm species identity. Genetic diversity of these putative B. meridionalis was low and indicated a single population around South Georgia. We are currently developing faster-evolving microsatellite markers to more robustly assess genetic diversity and population structure in this species.