Zooplankton Composition and Trophic Status of Aquatic Species in the Laptev and East Siberian Seas

The species composition, abundance, biomass, and distribution of zooplankton were studied on the shelf and slope of the northwestern Laptev Sea and the shelf of the East Siberian Sea in summer 2015. The trophic status of common zooplankton and fish species, as well as their position in the food webs of these two seas, has been determined based on stable carbon and nitrogen isotope analyses (δ 13 C and δ 15 N). Data of both stomach content and stable isotope analyses show significant age-related variations in the trophic status of the Arctic cod Boreogadus saida , which is the dominant fish species.