Organic matter and its transformation rates in different sea ecosystems

Abstract

The article includes proprietary data and data from literature from the last 30 years about the fluctuations in concentration and the elemental and biochemical make-up of the dissolved and particulate organic matter (DOM and POM, respectively) in the different ecosystems of the Barents Sea. The large variability of these values in both surface and deep waters is shown, depending on the intensity of the hydrological and biological processes.DOM concentrations varied from 59 to 664 μMCorg, while POM varied from 0.25 to 38.08 μMCorg. The reduction of the ice cover affected both the distribution and the qualitative composition of the DOM and the POM. This reduction, as well as the increased flow of Atlantic waters, contributed not only to an increase in the primary production of organic matter, but also to a significant intensification of redox and hydrolytic processes of its transformation, especially in the high-latitude part of the Barents Sea. The DOM of the sea is characterized by high C / P ratios, far exceeding those of Redfeld. At the same time, C / N ratios in the most productive waters are close to those of Redfeld. We highlighted four regions in the sea where concentrations of dissolved carbohydrates increase towards the bottom, which indicates that oil hydrocarbons are supplied here.