Seabird population shifts in the southern Baltic: A 30-year overview. Supplementary materials.

Description of Supplementary Materials The supplementary materials for the article "Seabird population shifts in the southern Baltic: A 30-year overview" provide detailed data and plots illustrating the changes in the abundance of seabird populations wintering in the Polish Exclusive Economic Zone (PEEZ) of the Baltic Sea from 2005 to 2023. Contents of the Supplementary Materials: Detailed plots for 21 speciesIndividual plots for 21 seabird species, showing abundance trends from 2005 to 2023. Each graph presents the population changes of specific species across the entire study area. Aggregated trends for all speciesCumulative plot depicting overall trends in the abundance of all studied seabird species from 2005 to 2023. This graph illustrate the total population changes at the level of the entire seabird community. Aggregated trends by ecological groupsPlots displaying abundance trends for two major ecological groups: benthos-eaters (species feeding on benthic organisms) and fish-eaters (species feeding on fish). These data show the differences in population changes between these groups over the period from 2005 to 2023. The supplementary materials are a crucial addition to the article, providing detailed information on the dynamics of individual species and ecological groups, and facilitating the understanding of the observed changes in the context of climate and anthropogenic impacts on the wintering seabird communities of the southern Baltic Sea.