Suspension settling effect on macrobenthos biomass distribution in the Hornsund fjord, Spitsbergen

[摘要] Seasonal variations and spatial distribution of suspension composition and concentration were determined in the Hornsund fjord on south Spitsbergen along with bottom sediment mineralogy and glacial-marine mud accumulation rates. These data were related to macrobenthos biomass distribution, as well as geochemical and hydrognphic data. The axial distribution of sediment accumulation rates follows exponential decay. Slopes of the seaward decay are different for individual meltwater sources in Hornsund and, in general, they are higher than in river-fed fjords. Intensity of suspension settling is enhanced by strong retardation of meltwater flow and turbulence within the shear layer of meltwater jet sliding over strongly saline water. The most intensive settling, controlling the overall efficiency of mud deposition (up to 35 cm/a) occurs in the ice-proximal jet zone of meltwater plume. It results from turbulent diffusion of dense suspension (>1, 000 mg/1) to the underlying still-water layer. Within the more dis...

[学科分类] 自然科学（综合）