Hyperbenthic Food-Web Structure in Kongsfjord: A Two-Season Comparison using Stable Isotopes and Fatty Acids.

Abstract

Current knowledge of the Arctic marine ecosystem is based primarily on studies performed during the polar day on the pelagic and benthic realms. Both the polar night and the hyperbenthic layer remain substantial knowledge gaps in the understanding of the marine system at high latitudes. To help address these knowledge gaps, this project investigates the hyperbenthic food web structure in Kongsfjord, a high-latitude, ice-free fjord, in September and January. The hyperbenthic food web was analyzed using a multi-biomarker approach including carbon and nitrogen stable isotopic signatures as well as fatty acid profiles of a variety of hyperbenthic taxa. Results suggest no difference in biomarker composition between September and January, although fatty acid profiles reveal a division in the community between pelagic and benthic consumers. Suggestions for seasonal similarities include slow turnover of stable isotopes and fatty acids in consumer tissue, as well as an increase in dependence on microbial-detrital food webs during the polar night.