Essential coastal habitats for fish in the Baltic Sea

Many coastal and offshore fish species are highly dependent on specific habitat types for populationmaintenance. In the Baltic Sea, shallow productive habitats in the coastal zone such as wetlands,vegetated flads/lagoons and sheltered bays as well as more exposed rocky and sandy areas are utilized byfish across many life history stages including spawning, juvenile development, feeding and migration.Although there is general consensus about the critical importance of these essential fish habitats (EFH)for fish production along the coast, direct quantitative evidence for their specific roles in populationgrowth and maintenance is still scarce. Nevertheless, for some coastal species, indirect evidence exists,and in many cases, sufficient data are also available to carry out further quantitative analyses. As coastalEFH in the Baltic Sea are often found in areas that are highly utilized and valued by humans, they aresubjected to many different pressures. While cumulative pressures, such as eutrophication, coastalconstruction and development, climate change, invasive species and fisheries, impact fish in coastalareas, the conservation coverage for EFH in these areas remains poor. This is mainly due to the fact thathistorically, fisheries management and nature conservation are not integrated neither in research nor inmanagement in Baltic Sea countries. Setting joint objectives for fisheries management and nature conservation would hence be pivotal for improved protection of EFH in the Baltic Sea. To properly informmanagement, improvements in the development of monitoring strategies and mapping methodology forEFH are also needed. Stronger international cooperation between Baltic Sea states will facilitateimproved management outcomes across ecologically arbitrary boundaries. This is especially importantfor successful implementation of international agreements and legislative directives such as the BalticSea Action Plan, the Marine Strategy Framework Directive, the Habitats Directive, and the MaritimeSpatial Planning Directive, but also for improving the communication of information related to coastal EFH among researchers, stakeholders, managers and decision makers. In this paper, efforts are made tocharacterize coastal EFH in the Baltic Sea, their importance and the threats/pressures they face, as well astheir current conservation status, while highlighting knowledge gaps and outlining perspectives forfuture work in an ecosystem-based management framework.