Ecologically or Biologically Significant Marine Areas (EBSA) are special areas in world's oceans that serve important purposes, in one way or another, to support the healthy functioning of oceans and the many services that they provide.

Following the voluntary commitment from HELCOM Contracting Parties at the United Nations Oceans Conference in June 2017, HELCOM started the process of identifying EBSAs in the Baltic Sea. The February 2018 EBSA workshop resulted in a proposal for areas for the Convention on Biological Diversity (CBD) to consider during the later half of 2018.

Nine Baltic marine areas were described by the workshop participants as ecologically or biologically significant, including five transboundary areas covering waters of two or more countries. The described EBSAs extend into 14 of the 17 Baltic Sea sub-basins. Altogether, they cover 23% of the Baltic Sea, slightly higher than the 19% the average in other areas of the world.

The described EBSAs are:

- Northern Bothnian Bay

- Kvarken Archipelago

- Åland Sea, Åland Islands and the Archipelago Sea of Finland

- Eastern Gulf of Finland

- Inner Sea of West Estonian Archipelago

- Southeastern Baltic Sea Shallows

- Southern Gotland Harbour Porpoise Area

- Fehmarn Belt

- Fladen and Stora and Lilla Middelgrund.

This dataset contains borders of these 9 areas and related attribute information.