Biochemical Composition and Energy Content in the Zooplankton of the Kara Sea

Abstract

This article presents a data set on ash, proteins, lipids, carbohydrates, chitin, organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) contents, macronutrients ratio (C, N, and P) and energy content of zooplankton (size fraction >500 μm) from the Kara Sea. Zooplankton samples were collected at 22 stations during the 76th interdisciplinary cruise of the R/V “Akademik Mstislav Keldysh” in July 2019. Proteins constituted the main component of zooplankton dry weight (43.39 ± 2.57% DW), while lipids amounted to 26.67 ± 2.28% DW and carbohydrates reached 4.91 ± 0.49% DW. Ash and chitin contents were 18.78 ± 1.39% and 3.68 ± 0.37% DW, respectively. The concentrations of macronutrients (C, N, and P) corresponded to the values of Arctic zooplankton and averaged 47.52 ± 1.12% for OC, 7.34 ± 0.39% for TN, and 0.70 ± 0.04% for TP of DW. The contribution of the individual components of the biochemical composition of zooplankton of the Kara Sea to the total OC revealed the dominant role of not only lipids but also proteins as compounds used by zooplankton in organic carbon accumulation. The Redfield ratio varied widely. The average values of C6.6:N, C70:P and N10.5:P were low and reflected certain features of the biochemical composition of the Kara Sea zooplankton community in the spring. The energy content of zooplankton of the Kara Sea ranged from 18.3 to 25.58 J mg-1 and averaged 20.25 ± 0.53 J mg-1 DW. The proportions of lipids and proteins in the total energy reserve of zooplankton were ~47 and ~46%, respectively, while the share of carbohydrates, their derivatives and chitin amounted to ~7%.