Do pelagic grazers benefit from sea ice? Insights from the Antarctic sea ice proxy IPSO25

Sea ice affects primary production in polar regions in multiple ways. It can dampen water column productivity by reducing light or nutrient supply, provide a habitat for ice algae and condition the marginal ice zone (MIZ) for phytoplankton blooms on its seasonal retreat. The relative importance of t...

Full description

Bibliographic Details
Published in:Biogeosciences
Main Authors: Schmidt, K, Brown, TA, Belt, ST, Ireland, LC, Taylor, KWR, Thorpe, SE, Ward, P, Atkinson, A
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus 2018
Subjects:
Online Access:http://plymsea.ac.uk/id/eprint/7863/
http://plymsea.ac.uk/id/eprint/7863/1/Schmidt%20et%20al.%20Biogeosciences_%202018.pdf
https://www.biogeosciences.net/15/1987/2018/
https://doi.org/10.5194/bg-15-1987-2018
Description
Summary:Sea ice affects primary production in polar regions in multiple ways. It can dampen water column productivity by reducing light or nutrient supply, provide a habitat for ice algae and condition the marginal ice zone (MIZ) for phytoplankton blooms on its seasonal retreat. The relative importance of three different carbon sources (sea ice derived, sea ice conditioned, non-sea-ice associated) for the polar food web is not well understood, partly due to the lack of methods that enable their unambiguous distinction. Here we analysed two highly branched isoprenoid (HBI) biomarkers to trace sea-ice-derived and sea-ice-conditioned carbon in Antarctic krill (Euphausia superba) and relate their concentrations to the grazers’ body reserves, growth and recruitment. During our sampling in January–February 2003, the proxy for sea ice diatoms (a di-unsaturated HBI termed IPSO25, �13CD