Table 2.

Environmental variables. See Appendix 1 for schematic overview maps of the general spatial patterns of the variables.

Variable	Abbreviation	Source
Water depth (m)	depth	1
Mean water depth in 2 km radius (m)	depth_2km	1
Slope of seabed (°)	slope	1
Slope of seabed in 2 km radius (°)	slope_2km	1
Salinity (PSU): long-term (2002–2008) mean	salinity	2,3
Wave exposure based on simplified wave model (m2 s−1): based on long-term (2003–2019) mean wind speeds and directions	wave	4
Current velocity (m s−1): long-term (2005–2019) mean	current	5
Water temperature in warm season (°C): long-term (2005–2019) mean in May–October	temp_warm	5
Water temperature in cold season (°C): long-term (2005–2019) mean in November–April	temp_cold	5
Concentration of nitrates (mmol m−3): long-term (2005–2019) mean values in winter (December-February)	nitrate	6
Concentration of phosphates (mmol m−3): long-term (2005–2019) mean values in winter (December-February)	phosphate	6
Chlorophyll a content of sea surface (mg m−3): long-term (2005–2019) mean	chl	6
Proportion of ice cover (0…1): long-term (2000–2016) mean	ice	7
Proportion of soft sediment (0…1)	sediment	2

Sources:

1—Bathymetric data by Estonian Maritime Administration (georeferenced depth raster with 10 m pixel size).

2—Databases of the Estonian Marine Institute, University of Tartu.

3—COHERENS ocean circulation model⁵⁷.

4—Simplified wave model based of fetch and wind data^58,59.

5—Copernicus Marine Environment Monitoring Service’s Baltic Sea Physics Reanalysis product BALTICSEA_REANALYSIS_PHY_003_011 (https://resources.marine.copernicus.eu/product-detail/BALTICSEA_REANALYSIS_PHY_003_011).

6—Copernicus Marine Environment Monitoring Service’s Baltic Sea Biogeochemical Reanalysis product BALTICSEA_REANALYSIS_BIO_003_012 (https://resources.marine.copernicus.eu/product-detail/BALTICSEA_REANALYSIS_BIO_003_012).

7—Ice data developed by the Marine Systems Institute, Tallinn University of Technology⁶⁰.