Abundance of mesozooplankton in the western part of the Black Sea during Mare Nigrum cruise S-RO1

The SESAME dataset contains mesozooplankton data collected during April 2008 in the North-Western part of Black Sea (between 44°46' N and 42°29'N latitude and 28°64'E and 30°59'E longitude). Mesozooplankton sampling was undertaken at 9 stations where samples were collected using a Hensen net in the 0-10, 10-25, 25-50, 50-100, 100-150, 150-200 m layer. The dataset includes 29 samples analysed for mesozooplankton species composition and abundance. The entire sample or an aliquot (1/2 to 1/4) was analyzed under the binocular microscope. Calculations of zooplankton abundance are made by the following formulae, in accordance with the Report of the third ICES/HELCOM workshop on quality assurance of Biological measurements Warnemünde, Germany, 1996. M - number of counted specimens (ind.), Vf - volume of filtrated water (m³), and K - counted part of sample. (http://www2008.io-warnemuende.de/research/helcom_zp/documents/qa_zp_part.pdf)

Cs-137 and Co-60 isotopes and sedimentation rates in Late Holcene sediments from the Northwestern Black Sea

Results of measurements of Cs-137 and Co-60 concentrations in bottom sediments of the Northwestern Black Sea indicate inhomogenity of their distribution both over the studied area and along sediment cores. Intermittency of sediment layers with different concentration of radionuclides in the cores reflects active horizontal movements and redistribution of sediments on the shelf and continental slope. As a result sediment layers dated by the Chernobyl mark as seven years old were found in the 5-7 cm depth layer. Maximum Cs-137 concentration in the surface sedimentary layer on the shelf was 42 mBq/g. Maximum Co-60 concentration of 1320 mBq/g was measured due to a hot particle. No correlation was found between Cs-137 and the Co-60 contents.

(Table 1) Conditions of vertical near-bottom profiling and the main parameters of the benthic boundary layer in several regions of the Black Sea shelf

Measurements of 14 vertical profiles of currents and hydrological parameters in the near-bottom layer with depth resolution of 0.1 m were carried out in several regions of the Black Sea shelf, at five points over the continental slope, and in three deep water regions. The upper boundary of the benthic boundary layer (BBL) was reliably determined at a point at distance from 5-7 to 35-40 m from the bottom where the gradients of density and current velocity changed. Experimental data obtained were used to determine the coefficient of bottom friction, friction velocity, coefficients of vertical diffusion of momentum and density, and vertical fluxes of temperature and salinity in the BBL.