The layer depicts the pressure of eutrophication in the Baltic Sea, based on the data from the HOLAS 3 integrated eutrophication assessment. The methodology utilizes the Eutrophication Quality Ratios (EQRS) available for each HELCOM assessment unit on level 4b.

The results of integrated eutrophication assessment combines the information of the three MSFD criteria groups (C1: Nutrient levels, C2: Direct effect, C3: Indirect effect) and use this value as an indication of pressure for each assessment unit.

The Spatial Impact and Pressure Assessment is carried out using a 1x1km grid while the Integrated eutrophication status is assessed on vector based HELCOM assessment units, the vector data are rasterized. First, the vector data are rasterized to 100x100m resolution, and after that it is aggregated to a 10x10km grid using a mean value. A 10 km grid is used in order to make the gradients between assessment units slightly smoother and finally the values converted to 1x1 km resolution. The scale for the pressure values in the map (0.26-1) represents the scale in the original source data.