The data contain habitat suitability (given in %) and biomass (given in tons) of commercial fish species in the North Sea and Baltic Sea. For the North Sea, habitat suitability is shown for the 1970s and as a change in response to climate change across decades from 1970 to 2050 and 2090. For the Baltic Sea, habitat suitability is shown for the 1990s and as a change in response to climate change across decades from 1990 to 2050 and 2090. Habitat suitability was estimated using a species distribution model (TIMoFiD, Thünen-Institute Model of Fish Distribution). The model used fish abundance and environmental data collected during the ICES-coordinated International Bottom Trawl Survey over 51 years in the North Sea and 31 in the Baltic Sea (https://www.ices.dk/data/data-portals/Pages/DATRAS.aspx). Temperature data used for model fitting were retrieved from AHOI (https://www.thuenen.de/en/institutes/sea-fisheries/projects/a- physical-statistical-model-of-hydrography-for-fishery-and-ecology-studies-ahoi), whereas those used for projections were retrieved from MPIOM (Max Planck Institute Ocean Model), for the North Sea, and MOM (https://www.gfdl.noaa.gov/mom-ocean-model/), for the Baltic Sea (both under the climate scenario RCP8.5). Biomass distribution in 2050 and 2090 were mapped according to habitat suitability as redistribution of three scenarios of total biomass (high, medium and low). Those scenarios were retrieved based ICES Stock assessment time-series (https://www.ices.dk/data/assessment-tools/Pages/stock-assessment-graphs.aspx). Further details are provided in the attached technical report.

• Spatial coverage of the datasets: North Sea: 61 °N – 51.2 °N and 3.9 °W – 9.7 °E; Baltic Sea: 58.4 °N – 54.4 °N und 10.1 °E – 21.5 °E* Read the attached documentation (pdf) for details and description of the method used.