Special Areas under MARPOL
The designation of Special Areas aims to prevent pollution from shipping such as discharges of noxious substances, sewage and emissions of sulfur and nitrogen. In Danish waters, special area regulation under MARPOL is in place in the North Sea and in the Baltic Sea.
IMO's list of Special Areas under MARPOL
IMO information about MARPOL Convention
Particularly Sensitive Sea Areas (PSSAs)
Marine areas may be designated as Particularly Sensitive Sea Areas (PSSAs) if they need special protection of marine ecosystems or associated cultural or historical values. In Danish waters, the Wadden Sea and the Baltic Sea are approved PSSAs by IMO.
IMO's list of Particularly Sensitive Sea Areas