Trophic relationships and isotopic gradients among arctic and subarctic marine fauna

Abstract

Results show a pronounced difference in the carbon isotope composition of suspension feeders collected in the southeastern Bering, Chukchi and western Beaufort Seas compared to the eastern Alaskan Beaufort and East Siberian Seas. This geographic difference is greatest at lower trophic levels but is observed throughout the food web as a progressive decrease in super(13)C content of fauna from the southeast Bering to the eastern Beaufort Sea. Predatory and omnivorous gastropods were super(13)C-enriched relative to most organisms at most geographic locations, occupying a trophic level equivalent to that of demersal fishes. Trophic relationships among fauna from the different geographical areas were similar.