Europe is home to 44 species of marine mammals including whales, dolphins, porpoises and seals, although the diversity of species varies between regional seas.

Of these, 36 species are whales, dolphins, and porpoises — collectively known as cetaceans — can be seen in Europe’s seas. This represent 42% of the cetacean species known around the world (Hoyt, 2003). The harbour porpoise is the only cetacean known to occur in all four of Europe's regional seas. Many cetaceans are considered resident (or regularly occurring) in Europe's regional seas (e.g. the common dolphin, the sperm whale, and the fin whale). Other cetaceans are considered to be visiting or occasionally-occurring species (e.g. the blue whale and the humpback whale).

In addition to cetaceans, eight species of seals can be seen in Europe's regional seas, but several of these species are restricted in their distribution to the Arctic Sea (e.g. the walrus, the harp seal, the bearded seal and the hooded seal). Although seals spend most of their time at sea, they come out of the sea onto coasts and beaches to mate; give birth; raise young; molt; escape from predators; and rest. Seals primarily feed on fish and marine invertebrates.

When assessing health of marine mammal populations of seals and cetaceans are assessed separately due to their different life histories and ecological requirements.

General outcomes of the  regional assessments 


In the Baltic Sea grey seal populations are increasing, while the ringed seal population is considered critical with less than 100 animals (Helsinki Commission, 2018).

The distribution of monk seal in the Mediterranean remains stable or expanding though it is still endangered and systematic monitoring is needed to assess overall status (United Nations Environment Programme, 2018).

In the Greater North Sea and Celtic Seas grey seal populations are also increasing, while the harbour seal is generally increasing there is also a decline in some areas (OSPAR Commission, 2017).


Cetacean surveys have restricted spatial and temporal coverage, therefore the knowledge on the distribution of the different species is limited, although it is now improving thanks to the use of alternative approaches (Waggitt, J., 2019).

At least four species of cetaceans in European waters are considered to be threatened (Atlantic right whale, Sei whale, Orcas and Blue whale), while two species are considered near threatened (Harbour porpoise and sperm whale) (Temple, H.J. and Terry, A., 2007).

In the Baltic Sea the local population of harbour porpoise in the Baltic Proper is of particular concern with an estimated population size of 500 animals (Helsinki Commission, 2018).

In the Mediterranean Sea there is some evidence of declining numbers of both fin whales and common dolphins (United Nations Environment Programme, 2018).

In contrast, in the Greater North Sea, the populations of minke whale, harbour porpoise and white beaked dolphin appear to be stable since 1994, although a shift in distribution southward is evident for harbour porpoise and minke whale (OSPAR Commission, 2017). 

Outcomes from the MSFD assessments

In 2018, Member States had to update the Good Environmental Status (GES) assessments performed under Marine Strategy Framework Directive Article 8. The present dashboard displays the overall status reported by countries for the features, where the results show which is the percentage of assessments where GES has been achieved, not achieved or is unknown or not assessed.