Primary Production and Associated Environmental Conditions in the East Siberian Sea in Autumn

Abstract

The spatial variability of primary production in the East Siberian Sea over a large-scale aquatic area was characterized for the first time by the data of cruise 69 of R/V Akademik Mstislav Keldysh in September 2017. The value of the water column primary production IPP amounted to 28 ± 13 mg C/m² per day, which pointed to extreme oligotrophy of the treated areas during the autumn. The IPP value was limited by low incident and subsurface insolation, as well as by the concentration of nitrates. The shortage of inorganic nitrogen was partially compensated by ammonium, which also constituted the buffer preventing a phytoplankton deficiency in nitrogen.