High-resolution habitat mapping on mud fields: new approach to quantitative mapping of Ocean quahog

During 2009-2012 stocks of the bivalve Arctica islandica (Linnaeus, 1767) (Ocean quahog) in Kandalaksha Bay (the White Sea) has been assessed using a side-scan sonar, grab sampling and underwater photo imaging. Structurally uniform localities were highlighted on the basis of side-scan signal. Each type of a signal reflects combination of sediment type, microtopography and structural characteristics of benthic community. The distribution of A. islandica was the predominant factor in determining community structure. Seabed attributes considered most significant were defined for each type of substrate type. Relations of sonar signal and sediment type were used for landscape mapping based on sonar data. Community characteristics at known localities were reliably interpolated to the area of survey using statistical processing of geophysical data. A method of integrated sonar and sampling data interpretation for high-resolution mapping of A. islandica by biomass groups, benthic faunal groups and associated habitats was developed.