The IUCN Red List (2009) has the harbour porpoise listed as LC (least concern).
The species is currently listed as CITES Appendix II.
Hunting and exploitation by humans, exposure to environmental contaminants and incidental capture in fishing nets are the main threats to the harbour porpoise (Jefferson et al, 2008).
The European Union (EU) has adopted regulations to reduce the incidental catch of small cetaceans in nets in EU waters (IUCN, 2009). Regulations include restricting Baltic Sea drift net fisheries, mandatory use of acoustic deterrent devices in some EU gillnet fisheries in the North and Baltic Seas, and the use of onboard observers on vessels of over 15m in length (IUCN, 2009).
The Natural History Museum, London, is part of a government-funded collaborative UK research group gathering data on strandings. These data help inform conservation policy makers at both UK and EU level (NHM strandings website, UKCSIP website). They are the most frequently stranded of all cetacean species in UK waters.