Deep dive...into Beluga whales

One of the smallest species of whale, the beluga whale belongs to the family Monodontidae, along with the narwhal.  

Weighing in at up to 1.5 tonnes and measuring between four and six metres in length, the beluga is also known as the white whale. It begins life as a dark grey calf but its skin lightens as it ages, becoming white when the animal reaches physical maturity.  

Its white skin helps the beluga to camouflage itself in the Arctic and sub-Arctic regions where it’s found. The beluga whale is recognisable by the melon on its top of its head which helps to focus and modulate its vocalisations. Belugas are known as the ‘canaries of the sea’ because of the wide range of communication sounds they use, including clucks, mews, chirps, trills, whistles and squeals. 

The melon on its head can change shape while it makes sounds. This, along with the flexibility that the beluga has in its neck vertebrae, means the animal can make facial expressions and move its head side to side. These actions often come across as endearing to humans (a reason it was so heavily targeted by the captive animal industry).  

The beluga’s scientific name is Delphinapterus leucas which translates to ‘dolphin without a fin’. Instead of a dorsal fin, the beluga has a tough dorsal ridge which helps it to easily swim under ice floes.  

But don’t get confused by its scientific name, the beluga is most definitely a whale, belonging to the toothed whale group. The species has 18 to 20 teeth in both its upper and lower jawbones.  

The beluga has a thick layer of blubber, which makes up to 40 per cent of its weight. It also has a thick layer of skin. Both of these are needed to keep it warm in the cold Arctic waters.  

Belugas are very social animals, coming together in pods to migrate, hunt and interact with others. They’re also naturally curious, often approaching boats and divers, and naturally smart. This means they can easily be trained, which has been exploited by marine parks, zoos and even by the U.S. and Russian naval forces.  

Check out this New York Times article about navies training dolphins and whales.  

The average life span of a beluga whale in the wild is 35 to 50 years.  

Belugas live all around the sea ice in the Arctic and sub-Arctic. The regions include Russia, Canada, Greenland and Alaska. Most populations migrate as the sea ice changes in the Arctic – as ice forms in the autumn, they move south and then return again in the spring when the ice breaks up.  

However, even during the winter, they’re fine with swimming around thin ice, which they can break through to breathe. Belugas are often found along coastal bays and inlets and are equally comfortable in freshwater and saltwater.  

Some populations have become resident in areas, including the Cook Inlet in Alaska where they are recognised as ‘critically endangered’.  

Occasionally, belugas have gone off track in their navigation. In 2018, one was spotted in the River Thames in London but fortunately it returned later to the sea. Find out more about the individual who was given the name Benny the Beluga.  

In 2022, another beluga made its way up the River Seine in Paris. It was successfully rescued to be transported to the sea but sadly had to be euthanised when it became unwell and couldn’t breathe. Read more in this BBC article.

The beluga whale is listed as ‘Least Concern’ globally on the IUCN Red List of Threatened Species, though it is defined as endangered or depleted in specific regions of the world e.g. Cook Inlet in Alaska, Sakhalin-Bay-Nikolaya Bay-Amur River in Russia.  

Globally, the beluga whale population is estimated to be 136,000.  

Beluga whales eat a wide variety of fish and shellfish species including salmon, herring, cod, octopus, squid, smelt, flatfish, crabs, shrimp and molluscs. They’re also known to eat snails and sandworms.  

The species relies on its hearing and its ability to echolocate (using the melon) to hunt for prey. Belugas also have really good vision in and out of the water.  

Beluga whales are at risk of vessel strikes throughout their range but the threat is much higher in areas with busy ship traffic.  

Climate change and pollution are a threat to all whales and dolphins because of the loss of habitat as waters become warmer.   

As their life cycle and habitat is so closely connected to life in the Arctic circle, beluga whales are a species more affected globally by climate change and the melting of the polar caps. The effects include reduction in food sources and changes in migration patterns.
Plastics and micro plastics, along with chemical pollutants, entering into the water system are a serious threat to all creatures in our ocean.  
Beluga whales, like other cetaceans, use noise to communicate and to locate prey. Increased noise pollution from vessels and other human activity interferes with this ability.  

With their great blubber stores, research shows that belugas tend to accumulate more chemical contaminants in their bodies which affect their long-term health.  

Like other cetaceans, beluga whales can become entangled in fishing gear which goes on to cause injury, fatigue, comprised feeding and sometimes even death.  

Belugas are hunted by polar bears and orcas, being more vulnerable if they get trapped under the Arctic ice. The whales are also hunted by indigenous people of the north. Thankfully commercial hunting of beluga whales is no longer permitted.