Weddell seal

The Weddell seal (Leptonychotes weddellii) is a relatively large and abundant true seal. It lives in areas surrounding Antarctica, especially around the Southern Ocean known as the Weddell Sea. This seal was discovered and named in the 1820s by British sealing captain James Weddell during his expeditions.

Weddell seals are special because they live on the fast ice close to the Antarctic continent. This makes them easy for scientists to study, as they are often near research bases. They are the only species in their genus, called Leptonychotes.

Description

Weddell seals are large seals. They are about 2.5 to 3.5 meters long and weigh between 400 and 600 kilograms. They have big bodies and short fore flippers. Males are usually a bit lighter than females but may have thicker necks and broader heads.

These seals have thin fur on most of their bodies, with some bare areas around the flippers. Their fur color changes with age and season. It can be bluish-black on the back and lighter grey or silver on the belly. Baby seals, called pups, are born with soft, fuzzy coats that change color after a few weeks. Pups start at about half their mother's length and grow quickly.

Behaviour

Weddell seals are often seen on ice that is stuck to land, called fast ice. They like to gather in small groups around cracks and holes in the ice. During winter, they stay in the water to avoid heavy snowstorms, only sticking their heads up through holes in the ice to breathe. These seals stay in one place and move around the ice as it changes with the seasons.

When looking for food, Weddell seals dive deep into the water. They can dive up to 600 meters deep and stay underwater for about an hour. They mainly eat fish, small sea creatures, and squid.

Weddell seals return to the same icy areas each spring to have their babies and mate. Most of the time, they have one baby each year, but sometimes they can have two. The babies are born on the ice and can swim about two weeks after they are born. Mothers and babies recognize each other by smell and special sounds at first. The seals start mating when they are about six to eight years old.

These seals talk to each other using different sounds. Babies make special higher-pitched sounds when they are hungry to call their mothers.

Taxonomy

In the past, the name of the Weddell seal was sometimes spelled wrong. Scientists now use the right spelling. You might still see the old spelling in old books.

Weddell seals look similar to two other seals that live in the same area: the Ross seal and the crabeater seal. It can be hard to tell them apart.

Population status

Weddell seals are the second most abundant seal species in Antarctica, after the crabeater seal.

The latest estimates say there are about 202,000 female Weddell seals. These numbers come from satellite images taken in November 2011. This count includes only females because males are mostly underwater during that time. There are probably fewer male seals than females.

Counting these seals is hard because they live in wide areas. Better satellite images and help from many people might make future counts easier.

Threats

During early Antarctic exploration, Weddell seals were hunted for food and oil. This made their numbers drop a lot. But since commercial sealing stopped in the 1980s, their populations have grown again.

Today, scientists watch how climate change might affect these seals. Changes in temperature can change the sea ice and food supply, which might make it harder for baby seals to survive. Some seals live on land in places like South Georgia, showing they can adapt, but more research is needed.

Research bases in Antarctica used to bother the seals, but rules now protect the area from harmful activities like mining and oil drilling. However, more tourists visiting Antarctica might still affect the seals' behavior and where they live, though scientists are still studying this.

Right now, there aren’t many problems between seals and fishing, but new fisheries, especially for Antarctic toothfish, could change that, so careful planning is important.

Conservation status

The Weddell seal is protected by the Antarctic Treaty and the Convention for the Conservation of Antarctic Seals. It is considered to be of "least concern" by the IUCN. This species is not listed by CITES.