This WMS map layer shows selected areas from the dataset "Seabed sediments (grain size), detailed" and indicates where fine sediments are likely to accumulate due to weak bottom currents. Such areas are typically dominated by silty and/or clayey and may include areas with fine-grained sediment deposited on top of coarser material. The map layer is intended for use at map scales 1:10 000 – 1:50 000.

Accumulation basins are the natural depressions on the sea floor with very weak bottom currents and prevailingly fine grained sediments. The renewal of bottom water in natural depressions on the seafloor my be so slow, that input of extra organic matter (f.ex. from fish farms) may result in reducing conditions.