A Particularly Sensitive Sea Area (PSSA) is an area of the marine environment that needs special protection through action by the IMO because of its significance for recognized ecological socio-economic or scientific attributes where such attributes may be vulnerable to damage by international shipping activities.

IMO is the only international body responsible for assessing proposals for and designating areas as PSSAs and adopting measures applicable to international shipping. This publication provides the reader with an overview of all PSSAs designated by the MEPC since 1990.