1. Estimating human impacts on marine ecosystem by the Baltic Sea Impact Index
Samuli Korpinen
Kuva: Ilkka Heikkinen

2. The BSII formula , where: P: a pressure (scoring 0-1),
E: an ecosystem or its component (scoring 0,1),
μ: an impact weightfor each PxE combination (scoring 0-4)

3. Pressure data in BSII Spatial data forced into 5 x 5 km squares
An intensity parameter, log-transformed
Normalization to 0-1, where maximum value = 1.0
Each pressure is linked to at least one activity

4. Ecosystem data Can include multiple data layers per grid cell.
Benthic cumulative impacts with 1 layer only.
Forced to the same grid cells as pressures.
Presence or absence (but could be 0-1 probability).

5. Sensitivity data
Now: Habitat sensitivity defined by recoverability and resistance.
(Previously: included also ’severity’).
Scored as 0, 1, 2, 3 or 4  average.
Expert online survey.
Literature-based scores.