Zooplankton in Bays of the Novaya Zemlya Archipelago: Composition, Distribution, and Role in Phytoplankton Grazing and Biosedimentation

Abstract

The zooplankton community in two bays of the eastern coast of the Novaya Zemlya archipelago (Blagopoluchiya Bay and Tsivolki Bay) has been studied for the first time. Copepods of the genus Calanus—C. glacialis/finmarchicus and C. hyperboreus—dominate the zooplankton of the bays in terms of biomass (76–93%). These copepods reached the highest abundance in Blagopoluchiya Bay. The total abundance (70 000 ind./m²) and biomass (60 g/m²) of the population were many times higher than the maximum values recorded from waters of the Kara Sea shelf. The ration values for these copepods ranged from 1.5 to 20 µg C ind.^–1 day^–1 at different copepodite stages. The rate of grazing on phytoplankton biomass and production by zooplankton varied within 1.5–15.6% and from 3 to 127%, respectively. In the considered bay, the flux of organic carbon and suspended particulate matter contained in Calanus fecal pellets reached 157.5 mg C_org m^–2 day^–1 and 1574 mg m^–2 day^–1, respectively. In Tsivolki Bay, the total zooplankton biomass (6.6 g/m²) was several times lower. This has led to a decrease in its role in phytoplankton utilization (0.6–2.4% of phytoplankton biomass and 1.9–18% of phytoplankton production), as well as to a less intensive flux of suspended particulate matter (47.8 mg m^–2 day^–1) and organic carbon of copepod fecal pellets (2.6 mg C_org m^–2 day^–1) in the bay.