Zooplankton

Ecology

Krill

Pelagic zone

Euphausia

Geology

Overwintering

Algae

Biology

Environmental science

Oceanography

Sea ice

Antarctic krill

Fishery

Frontiers in Marine Science

Antarctic krill Euphausia superba ('krill') constitute a fundamental food source for Antarctic seabirds and mammals, and a globally important fisheries resource. The future resilience of krill to climate change depends critically on the winter survival of young krill. To survive periods of extremely low production by pelagic algae during winter, krill are assumed to rely partly on carbon produced by ice algae. The true dependency on ice algae-produced carbon, however, is so far unquantified. This confounds predictions on the future resilience of krill stocks to sea ice decline. Fatty acid (FA) analysis, bulk stable isotope analysis (BSIA) and compound-specific stable isotope analysis (CSIA) of diatom- and dinoflagellate-associated marker FAs were applied to quantify the dependency of overwintering larval, juvenile and adult krill on ice algae-produced carbon (αIce) during winter 2013 in the Weddell-Scotia Confluence Zone. Our results demonstrate that the majority of the carbon uptake of the overwintering larv...

Ice Algae-Produced Carbon Is Critical for Overwintering of Antarctic Krill Euphausia superba