Regional-scale mapping of the sediments and biotopes of the Barents Sea through synthesis of existing data

Abstract

Knowledge of the distribution of seabed sediments, benthic communities and their associated environment (biotopes) provides important baseline information for sustainable management of the oceans. The Barents Sea comprises a vast area of continental shelf spanning international boundaries, where this type of information is in increasing demand for management related issues in these high-latitude waters. Synthesis of existing data originally obtained for other purposes can provide an important first step in making the required information available, as well as helping to identify areas where further mapping should be prioritised. We present two related regional-scale maps recently generated for a large part of the Barents Sea continental shelf where varying amounts of existing data were available from Norwegian and Russian institutions: (1) a map showing the distribution of seabed surface sediments (1:3,000,000), and (2) a map showing the predicted distribution of benthic biotopes (4 km raster resolution) based on Random Forest modelling. The biotope map makes use of the sediment map as a key predictor variable, together with bathymetric, oceanographic and other environmental variables. Biotope classes are based on species composition as identified from benthic trawl samples. Compilation and synthesis of geo-referenced data from various sources can produce valuable results but can also lead to uncertainties in the resultant map products which are important to convey to data users. To support our thematic maps we present a confidence assessment of the foundation datasets contributing to the sediment map. We also discuss further issues related to map confidence and scope for updating the maps as new data become available.

Synthetic shelf sediment maps for the Greenland Sea and Barents Sea

“…Finally, we used our model to predict NGU‐SEVMORGEO sediment classes and calculate derived fields for the East Greenland shelf which is currently inaccessible due to persistent sea ice cover. While our results provide a modest extension to the area mapped by NGU‐SEVMORGEO in the Barents Sea (Lepland et al, 2014), as well as new variables, our results for the East Greenland shelf are the most comprehensive to date (to our knowledge).…”

“…Our sediment maps are an extension of NGU‐SEVMORGEO’s marine sediment overview product (Lepland et al, 2014). The accuracy of our maps are dependent on the initial accuracy of these data.…”

“…The Norwegian geological survey in partnership with the Russian SEVMORGEO published an overview document of seabed sediment classes in the Barents Sea (Lepland et al, 2014). We trained a random forest model, run in H2O (Aiello et al, 2018), to predict these seabed classes across our grid.…”

“…Ice cover in the Barents Sea is less extensive (Kwok et al, 2013; Ogi et al, 2016), and anthropogenic activity levels are higher (Eguíluz et al, 2016). The Norwegian Geological Survey (NGU) in partnership with the Russian Federal State Unitarian Research and Production Company for Geological Sea Survey (SEVMORGEO) provides a spatial overview product of seafloor sediment classes in the Barents Sea (Lepland et al, 2014). NGU‐SEVMORGEO defines 36 sediment classes determined by combinations of consolidated substrate, as well as proportions by weight of sediment grains binned as gravels, sands and a combination of silt and clay.…”

“…Project schematic. We predicted NGU‐SEVMORGEO sediment classes (Lepland et al, 2014), using GEBCO bathymetry (GEBCO, 2019), SINMOD velocity (Slagstad & McClimans, 2005) and ECMWF wave data (Laloyaux et al, 2018) as predictors (blue). We then predicted sediment classes over a larger spatial grid, before deriving additional seafloor properties which are available with this manuscript (yellow).…”