The Baltic Sea Impact index (BSII) assesses the potential cumulative impact of pressures over ecosystem components. The BSII is based on georeferenced datasets of human activities (28 datasets), pressures (17 datasets) and ecosystem components (57 datasets), and sensitivity estimates of ecosystem components to pressures (sensitivity scores). Cumulative impacts are calculated for each assessment unit (1 km2 grid cells) and the data set covers the time period 2016-2021.

Spatial Pressure and Impact Assessment (SPIA) is the framework for assessing spatial and cumulative pressures and impacts in HOLAS 3, where the BSII presents the full cumulative impact assessment where all pressures and ecosystem components are included. The framework also includes results for the Baltic Sea Pressure Index (full cumulative pressure assessment), and other thematic assessments where a subset of pressure and ecosystem layers are used.

For more info please

- visit the HOLAS 3 website ( http://stateofthebalticsea.helcom.fi/)

- download the report thematic assessment of spatial distribution of pressures and impacts 2016-2021 ( https://helcom.fi/post_type_publ/holas3_spa)

- or check out the HELCOM SPIA online tool to make calculations for any desired combination of pressures and ecosystem layers ( https://maps.helcom.fi/website/bsii/).

Please scroll down to "Lineage" for a more detailed description of the methodology.