Concentration and composition of aerosols over the North Atlantic in August 1995

Data on composition of aerosols are considered. Investigations include electron microscopy, grain size, mineralogical and chemical analyses. Samples of aerosols were collected Cruise 37 of R/V Akademik Mstislav Keldysh along a transatlantic section along 40°-50°N. Variability of concentrations and composition of aerosols with distance from continents is shown: concentrations of aerosols decrease by factor of ten and more. Significant portion of mineral components in aerosols collected over the continent is replaced by organic matter due to mechanical differentiation during transportation. Such anthropogenic components as soot, ash, and combustion spheres were detected in all samples. North African dust was found in one sample in the western part of the section.

Abundance and biomass of the benthic infauna of the North Sea

In 1986 participants of the Benthos Ecology Working Group of ICES conducted a synoptic mapping of the infauna of the southern and central North Sea. Together with a mapping of the infauna of the northern North Sea by Eleftheriou and Basford (1989, doi:10.1017/S0025315400049158) this provides the database for the description of the benthic infauna of the whole North Sea in this paper. Division of the infauna into assemblages by TWINSPAN analysis separated northern assemblages from southern assemblages along the 70 m depth contour. Assemblages were further separated by the 30, 50 m and 100 m depth contour as well as by the sediment type. In addition to widely distributed species, cold water species do not occur further south than the northern edge of the Dogger Bank, which corresponds to the 50 m depth contour. Warm water species were not found north of the 100 m depth contour. Some species occur on all types of sediment but most are restricted to a special sediment and therefore these species are limited in their distribution. The factors structuring species distributions and assemblages seem to be temperature, the influence of different water masses, e.g. Atlantic water, the type of sediment and the food supply to the benthos.