Krill feeding in fjords of the West Antarctic Peninsula (and a few penguins & seals)

Alison Cleary, Norwegian Polar Institute Cambridge Fluids Network - fluids-related seminars 8 May 2017 11:00am British Antarctic Survey, Room 307 We investigated feeding by Antarctic krill, Euphausia superba, in fjords and adjacent open waters of the West Antarctic Peninsula using next generation sequencing of gut contents. One hundred and seventy four krill were analysed, and showed a diet consisting mainly of diatoms, but also containing micro and mesozooplankton. The most striking result was the high proportion of sequences from Chaetoceros spp. diatoms in the gut contents of krill collected in fjords. This high proportion of Chaetoceros spp. was not observed in the guts of krill collected off-shore, and could not be explained by differences in the bulk phytoplankton communities. The physical characteristics of fjords are conducive to the formation of phytoplankton layers, and we suggest the most parsimonious explanation for the observed dominance of Chaetoceros spp. sequences in the guts of krill from fjords is krill feeding on phytoplankton layers. I will also briefly introduce our new, and marginally related, project investigating population genomics of macaroni penguins and Antarctic fur seals in a circumpolar context.