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Harbour porpoise

life science Maturity 7-9 Next article →

The harbour porpoise, known scientifically as Phocoena phocoena, is a small cetacean that lives in cool coastal waters.

Phocoena phocoena.2
Phocoena phocoena.2

It is one of eight living species of porpoise. These animals are highly familiar to whale watchers because they stay near coasts or river estuaries. They can even travel hundreds of kilometres inland through rivers. The species is widespread across the North Atlantic, the North Pacific, and the Black Sea.

Ecomare - bruinvis Berend (berend3)
Ecomare - bruinvis Berend (berend3)

Physically, the harbour porpoise is quite robust. At birth, they are about 60 centimetres long. Most adults weigh between 50 and 70 kilograms. Interestingly, females are often heavier than males. Their bodies are dark grey on the back, fins, and tail. The sides are a lighter, speckled grey. Their undersides are mostly white with grey stripes along the throat. Some individuals even appear anomalously white in places like the North Atlantic or the Bay of Fundy.

Westport, WA Maritime Museum - Harbor Porpoise 01A
Westport, WA Maritime Museum - Harbor Porpoise 01A

To navigate and hunt, these animals use a mechanism called echolocation. They produce vocalizations consisting of short clicks. Each click lasts between 0.5 and 5 milliseconds. These clicks occur in bursts that can last up to two seconds. The frequency of these sounds is between 1000 and 2200 hertz. By listening to how these sounds bounce off objects, the porpoise can locate prey. This is essential for their survival in murky coastal waters.

Harbour porpoises are categorized into several distinct populations or subspecies. In the North Atlantic and West Africa, they are classified as P. p. phocoena. The populations in the Black Sea and Sea of Azov are P. p. relicta. There is also an unnamed population in the northwestern Pacific. In the northeastern Pacific, they are known as P. p. vomerina. Recent studies suggest the North Atlantic population is even more complex, with at least three genetically distinct subspecies.

Ecomare - bruinvis Michael met penis (michael-penis-4580-sd)
Ecomare - bruinvis Michael met penis (michael-penis-4580-sd)

The history of the porpoise name is quite fascinating. The English word comes from Old French and Medieval Latin. The Latin roots combine "porcus" (pig) and "fish." This suggests they were once seen as "sea swine." Their scientific name, Phocoena phocoena, comes from the Greek word "phōkaina," meaning "big seal." This description was famously made by the philosopher Aristotle. In Norway, they are called "nise," a word related to sneezing. This refers to the sound they make when surfacing to breathe.

These animals have a very active feeding lifestyle. They primarily eat small schooling fish like herring, cod, and sardines. They may also eat squid or crustaceans. A study near Denmark showed they are very efficient hunters. They can catch 200 fish per hour during the day. At night, that number can rise to 550 fish per hour. They catch about 90% of the fish they target. To maintain their energy, young porpoises must eat about 7% to 8% of their body weight every day.

Harbor Porpoise Fjord Baelt Denmark
Harbor Porpoise Fjord Baelt Denmark

Despite their abundance, harbour porpoises face many natural and human threats. They are preyed upon by white sharks, killer whales, and grey seals. In some areas, bottlenose dolphins even attack them. The most significant human threat is bycatch. This happens when porpoises get caught in static fishing gear, like gill nets. These nets are anchored to the sea floor and can be 400 metres long. To help, researchers use "pingers," which are acoustic devices that scare porpoises away from the nets.

Verwesender Schweinswal 1
Verwesender Schweinswal 1
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🖼️ Images & Media (6)
File:Westport, WA Maritime Museum - Harbor Porpoise 01A.jpg
Westport, WA Maritime Museum - Harbor...
File:Ecomare - bruinvis Berend (berend3).jpg
Ecomare - bruinvis Berend (berend3).jpg
File:Phocoena phocoena.2.jpg
Phocoena phocoena.2.jpg
File:Ecomare - bruinvis Michael met penis (michael-penis-4580-sd).jpg
Ecomare - bruinvis Michael met penis...
File:Verwesender Schweinswal 1.JPG
Verwesender Schweinswal 1.JPG
File:Harbor Porpoise Fjord Baelt Denmark.JPG
Harbor Porpoise Fjord Baelt Denmark.JPG
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