Geomorphological and habitat mapping of the glaciated shelf (the Velikaya Salma Strait of the Kandalaksha Gulf of the White Sea, Russia)

Abstract The Velikaya Salma Strait is part of a fiard, typical of the Kandalaksha Gulf of the White Sea. Seabed topography, landscapes, and bottom sediments were studied in an area of 35.12 km2 (depths of 10–120 m) using geophysical methods, geological sampling, and visual observations. Macrobenthos distribution was sampled at 15–60 m depth and studied using an underwater camera. Structural-denudation, glacial, gravity, and tidal current landforms were identified on the Strait seabed. Bottom sediments vary from boulder–pebble to pelite. The bathymetric zonation of their distribution is disturbed when tidal currents encounter the dissected seabed topography and by gravitational displacements. Macrobenthos distribution has statistically significant dependence on bottom sediments grain size and depths. Galathowenia oculata–Chaetozone setosa community prevails on muddy sediment, and Macoma calcarea–Scoloplos acutus community prevails on sandy bottom. Statistical relationships between sidescan sonar images and macrobenthos distribution are stable in the areas of gently dismembered seabed and are lost in the areas of dissected topography.