Suspended Matter as an Index of Productivity in the Western Black Sea (Application for Productivity and Eutrophication Control)

Abstract

Suspended matter distribution and composition in relationship with different productivity parameters were investigated in the western part of the Black Sea (BS) for better understanding the scales of river influence and eutrophication in the area. Good correspondence between the total amount of suspended matter (SM), particulate organic matter (POM), total plankton biomass (Bo), algae biomass (Bp) and primary production (Pp) spatial variability is pointed out. The SM concentrations in the western BS change in the range of 0.3–7.0 mg/1, dependent on the level of productivity and river influence. The organic matter contribution to total SM shows general tendency of its insignificant growth from the open sea to the coastal regions. In surface waters the POM/SM ratio rises from 40% in the open sea, to 70% in shallow, more productive regions and from 33% to 55% in the euphotic zone respectively. Below the layer of photosynthesis, the OM portion in suspended material varies in the range of 18–28 without essential difference between shelf and open waters. The role of living biomass in the SM is found to elevate from 11% in the open and outer shelf regions, to 22–26% in shelf zone, on the average. The suspended matter composition analysis shows biogenic indigenous origin of the SM in the most part of the western Black Sea shelf. Results suggest the conclusion that the total suspended and particulate organic matter spatial variability reflects the production processes development in the western BS, induced by the river nutrient inflow and local eutrophication. The possibility of monitoring Black Sea productivity, by in-situ and satellite measurements of suspended matter and its components is discussed.