Marine landscape mapping of the south-eastern part of the Baltic Sea (Russian sector)

Abstract

Five different kinds of broad-scale characterizations of the marine environment were used for marine bottom landscape mapping. In addition to three “primary” environmental parameters of the BALANCE project – sediment types, available light and near-bottom water salinity two more were also taken into account: near-bottom temperature and ice cover. Combination of these parameters allows for distinguishing 21 types of marine bottom landscapes. The dominant landscape type is located far beyond the surface photic zone and not influenced by the ice-cover. It is characterized by mud sediment type, salinity of 11–18 psu and deep low variable relatively cold near bottom waters (4–8 оС) with ulterior seasonal variability. The most perspective marine landscape, from the point of view of nature conservation zones, is small area located in the Curonian Spit marine nearshore zone where bottom sediments are represented by the relict lagoon hard clays partly covered by sands. These clays are unique bottom oasis where the numbers of benthic organism species sharply increase in contrast to almost lifeless adjacent extensive sand areas.