International conference calls for urgent action to tackle harbour porpoise bycatch in Europe

April 18, 2024

Scientists attending an international conference in Italy have issued a plea for urgent action to protect harbour porpoises in European waters, highlighting that too many of these small cetaceans are being killed in fishing nets in European fisheries.

Letter of concern from scientists

Last week the 35th Annual Conference of the European Cetacean Society (ECS) took place in Catania, Sicily, Italy (cetaceans are the group of marine mammals that include whales, dolphins and porpoises). The gathering of nearly 600 scientists and conservationists has issued a letter of concern regarding the conservation of the harbour porpoise throughout Europe. The letter highlights particular concerns for porpoises in the Baltic Proper, the Belt Sea, the Black and Mediterranean Seas, the Northeast Atlantic (including the Celtic Sea) and the Iberian population of harbour porpoises off the Spanish and Portuguese coasts.

European laws are failing porpoises

The letter states that European laws have failed to manage harbour porpoise bycatch meaning that many populations of harbour porpoises in Europe are declining. Indeed, many European Union countries are failing to comply with the Habitats Directive which requires harbour porpoises to receive strict protection and for incidental capture and killing of porpoises to be monitored. The letter calls for action by countries both at national level and at ocean basin level.

Demand for urgent action

In the letter, the members of the ECS request “that the competent authorities urgently adopt and enforce regulations for effective measures to minimise and, where possible, eliminate harbour porpoise bycatch”. OceanCare’s Director of Science, Mark Simmonds, and Science Officer, Laetitia Nunny, attended the conference and both signed the letter. They have been calling for action to protect porpoises for many years and hope that this letter will help bring more attention to the crisis facing Europe’s smallest cetacean.

Harbour porpoise welfare impacted

As well as being of great conservation concern, bycatch also has an extremely negative impact on harbour porpoise welfare. When a porpoise becomes trapped in a fishing net it cannot reach the surface to breathe. It may injure itself as it struggles to escape from the net. The porpoise will experience high levels of stress before dying of asphyxiation. There is also the potential for other porpoises to be negatively impacted. If, for example, a mother porpoise is caught and dies in a fishing net, then her dependent calf would be left alone to starve to death.

Porpoise characteristics

The harbour porpoise is one of the smallest of all the cetaceans with adults reaching a length of only about 1.5 m. Males are usually smaller than females. They have a dark back, a lighter coloured tummy, rounded head with no beak and a small triangular dorsal fin. They usually keep a low profile in the water and live in small groups of between 1 and 10 individuals.

A myriad of threats for porpoises

As well as capture in fishing nets, harbour porpoises in Europe are threatened by marine pollution. Persistent chemicals present in European waters can have an impact on porpoises’ health, potentially including their ability to reproduce, which means that populations cannot easily recover from the decimation caused by their capture in fishing nets. Noise pollution and disturbance are other threats. Underwater noise from windfarm construction and shipping, for example, can push them out of important habitat. It can also mean that porpoises are not able to communicate effectively with each other.

The negative combined effects of these threats alongside the high levels of fisheries bycatch being recorded in Europe, means that harbour porpoises face a very uncertain future unless action is taken immediately. OceanCare continues to work to highlight the conservation and welfare issues facing marine species in Europe and beyond.


Letter of Concern

Article by Ida Carlén, Mark P. Simmonds and Laetitia Nunny on harbour porpoise conservation in Europe

Chapter by Ayaka Amaha Öztürk on bycatch in Europe in the OceanCare “Under Pressure” report


Photo: Anik Boileau/CERSI