Baikal seal

The Baikal seal (Pusa sibirica), also known as Lake Baikal seal or nerpa (нерпа), is a special kind of seal that lives only in Lake Baikal in Siberia, Russia. It is one of the smallest earless seals and is unique because it is one of the few seals that live only in freshwater. Most seals live in the ocean, but the Baikal seal calls Lake Baikal its home.

This seal is closely related to the Caspian seal, which lives in the Caspian Sea, and also to the ringed seal found in the Arctic Ocean. While there are other seals that sometimes live in freshwater, like some harbour seals in Canada or ringed seals in Finland, they are part of larger groups that also live in the ocean. The Baikal seal is different because it only lives in Lake Baikal.

Today, scientists think there are between 80,000 and 100,000 Baikal seals. This number is just right for the lake to support, and the species is not in danger right now. These seals are an important part of the unique wildlife in one of the world's deepest and clearest lakes.

Description

The Baikal seal is one of the smallest true seals. These seals usually grow to be about 1.1 to 1.4 meters long, which is roughly 3 feet 7 inches to 4 feet 7 inches. They weigh between 63 to 70 kilograms, or 139 to 154 pounds. The biggest Baikal seal ever found was 1.65 meters long and weighed 130 kilograms, or 290 pounds. Their weight changes through the year, being lowest in spring and highest in fall. Both male and female seals look very similar in size. They have a shiny, steel-grey coat on their backs and a lighter, yellowish coat on their bellies. Baby seals are born with a white, soft coat that they quickly change to a darker one like the adults. Very rarely, a Baikal seal may have a spotted coat.

Evolution

The skull shape of the Baikal seal shows it is closely related to the Caspian seal. Both types of seals seem to come from Arctic ringed seals. Long ago, they might have swum up rivers to reach Lake Baikal, or Lake Baikal could have been connected to the sea through a big body of water during an ice age. Scientists think these seals have lived in Lake Baikal for about two million years.

Distribution

The Baikal seal lives only in the waters of Lake Baikal; they are endemic there.

The areas of the lake where Baikal seals live change with the seasons and other environmental factors. These seals are usually alone for most of the year, sometimes far from other Baikal seals. More Baikal seals are found in the northern parts of the lake because the ice stays frozen longer there, which helps them have their babies. But in recent years, some have moved to the southern half of the lake, possibly to avoid hunters. In winter, when the lake is frozen, the seals keep a few breathing holes and stay close by without disturbing each other’s food. When the ice melts, Baikal seals usually stay near the shoreline.

Biology

The Baikal seal is a special kind of seal that lives only in Lake Baikal in Siberia, Russia. Its main food is a fish called golomyanka, which is found only in the lake. These seals eat a lot of golomyanka, especially in winter and spring. They also eat other fish and small water animals.

Baikal seals can dive very deep—up to 400 metres—and stay underwater for more than 40 minutes. They usually hunt for food at night and rest during the day. In autumn, they eat special fish that help clean their insides.

Female Baikal seals are able to have babies at around three to six years old, while males take a bit longer. They have their babies on the ice in late winter. The mother takes care of the baby alone, making a warm den under the ice for it. Baby seals grow quickly and are ready to eat solid food after a couple of months. They stay close to their mother until they are strong enough to explore on their own.

The oldest Baikal seals can live up to around 50 years.

Relation to humans and conservation

The Baikal seal is not in danger of disappearing. In 2008, it was listed as a species that is not threatened or endangered. There are thought to be between 80,000 and 100,000 Baikal seals living in Lake Baikal today.

In the past, people sometimes hunted Baikal seals for their fur. The number of seals that could be hunted was reduced over time to protect the population. Even with rules in place, some seals still die because they get caught in fishing nets or are taken by people who do not follow the rules.

Pollutants from factories and chemicals used in farming have also hurt the seals. These harmful chemicals can make the seals sick and more likely to catch diseases. One disease, called canine distemper, caused many deaths in the 1980s. Today, the levels of some harmful chemicals in the lake are lower, but others are increasing.

The biggest future danger to the Baikal seal may be global warming, which could change the cold environment of Lake Baikal and make it harder for the seals to survive.