Bioacoustics of Phocoena phocoena

Status and Conservation. CITES Appendix II. Classified as Least Concern on The [IUCN Red List. The subspecies relicta is classified as Endangered, and the Baltic Sea population, which only numbers ¢.500-600 individuals,is classified as Critically Endangered. Other subspecies have not been evaluated separately on The IUCN Red List. There has been a long and somewhat tragic history of human interactions with Harbor Porpoises. Hunting has occurred in many different parts ofits distribution, especially in northern European waters. Major hunts have occurred in the Black Sea, Baltic Sea, and the Bay of Fundy, and in the waters off western Greenland (the latter is still active). Many of these caused depletion of local populations. More recently, bycatch from fisheries, especially in various forms of gillnets or trammel nets, has been responsible for threatening existence of populations throughout the distribution of the Harbor Porpoise. The largest mortality has occurred in fisheries in the Gulf of Maine, western Greenland, North Sea, and Celtic Shelf, but smaller kills have occurred almost everywhere the Harbor Porpoise occurs. It is believed that Harbor Porpoises can normally detect gillnets at distances necessary to avoid entanglement, but accidents may happen due to attention shifts or auditory masking. Use of acoustic alarms (“pingers”) and other mitigation measures have managed to reduce mortality in many areas, but the only way to eliminate bycatch completely is to eliminate gillnets. Catches of Harbor Porpoises in trawls, set nets, herring weirs, pound nets, cod traps, and even anti-submarine nets have also been documented and have taken their toll. Other threats include detrimental effects of environmental contaminants, vessel traffic, anthropogenic noise impacts, prey depletion, and habitat deterioration or destruction. The Harbor Porpoise is not rare and not endangered. Globally, there may be more than 675,000 Harbor Porpoises. Nevertheless, particular populations in many areas have been impacted by human activities and quite a few of these are indeed threatened and in need of protection.