The Relation between Primary Production and the Flux of Particulate Organic Matter in the Sub-Arctic Coastal Sea

Abstract

The relation between primary production and the precipitating processes of particulate organic materials was manifested by measuring in situ some size-fractionated (No Screen, <690-μm and <350-μm) organic material fluxes and amino acids composition in the precipitating particles during a spring bloom and autumn in Funka Bay, the sub-Arctic coastal sea. The total flux (No Screen) of particulate organic material, in term of carbon, at a depth of 74 m during the spring bloom and the autumn accounted for, on average, 51% and 57% of primary production, respectively. However, the fluxes of particulate organic carbon in the <690-μm and <350-μm fractions were only, on average, 19% and 9% of primary production during the spring bloom, and 30% and 12% during the autumn, respectively. The composition of protein amino acids, the existence of glucosamine and detectable degrees of non-protein amino acids (γ-aminobutyric acid, β-alanine and ornithine) in the precipitating particles obtained from our sediment trap experiment demonstrated that the precipitating organic particles were dominated by some microzooplankton source materials even in the <350-μm fraction. At the coastal sea, the precipitating organic particles are as few as the phytoplankton itself produced in the euphotic zone, the bulk of the phytoplankton might be removed from a water column by the predation of zooplankton, and a part of the removed phytoplankton might change in larger-sized precipitating zooplankton source materials.KeywordsParticulate Organic MatterParticulate Organic CarbonSediment TrapProtein Amino AcidEuphotic ZoneThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.