Does Zooplankton Control Phytoplankton Development in White Sea Coastal Waters in Spring?

Grazing impact of dominant zooplankton species on phytoplankton was estimated in the coastal areas of the White Sea in spring. The material was collected on expeditions of the R/V Ekolog in June 2012 and 2015 in Kandalaksha Gulf and Onega Bay of the White Sea. The data on the composition and biomass of zooplankton showed that depending on the intensity of the warming of the water column at the beginning of productive season, the zooplankton community was at the early-spring or late-spring stage of seasonal development. Zooplankton grazing impact varied from 1 to 90% of phytoplankton biomass and from 7 to 470% of primary production. The results are discussed in relation to the hydrothermal regime and the phase of coastal plankton community succession in different years.