What should I know about seals?
There are 18 seal species still inhabiting the seas today, but not long ago there were 19 species. The Caribbean monk seal was last sighted in 1952 and is now listed as extinct. One of the seal species on the endangered species list is the Hawaiian monk seal (Monachus schauinslandi). The United States is one of many nations that are actively attempting to protect and bring back a healthy population of this endangered seal species.
Seals can be found in all the oceans and a few freshwater lakes, one of which is Lake Baikal in Russia which is the only place in the world where you can find it. There can be big differences between different species. The largest seal, the elephant seal, can weigh many times more than smallest seal. The elephant seal can weigh more than 5,000 pounds! Adult ringed seals, the smallest of all pinnipeds, can weigh as little as 110 pounds. Another difference is the coloration of the different seal species. The ribbon seal has white markings, like a ribbon, that encircle parts of their bodies. Some other seals are nearly uniform in color.
What are the characteristics of all seals? Well, seals do not have an ear that extends from the skull, but they can still hear well. Also, seals propel themselves through the water with their rear flippers while their front flippers are used for steering. The front flippers of seals are short with sharp claws. Seals cannot use their rear flippers to walk on land or ice and most appear awkward when moving on these surfaces. Seals have a torpedo like shape in the water and use their rear flippers to move rapidly to catch prey and escape predators.
We can classify seals according to where they live. Click on the links below to get more information on each specific group!
The Arctic ice seals breed on ice. The Arctic ice seals are threatened by more predators than their Antarctic relatives. Arctic seals live in the same regions as humans, foxes, wolves, dogs, wolverines, large birds and polar bears, all of which have been known to prey on seals. The polar bears do not always consume the seal meat, but they do consume the blubber. Arctic ice seal also have to contend with local populations of humans who hunt the seals for meat and fur. There is a higher level of danger from pollution in Arctic seas. Commercial fishing has decreased some populations of fishes the seals feed on.
Click on one of the ice seal species to view information about them!
- Ringed seal (Phoca hispida)
- Bearded seals (Erignathus barbatus)
- Spotted seals (Phoca largha)
- Ribbon seals (Phoca fasciata)
- Hooded Seal (Cystophora cristata)
- Harp Seal (Phoca groenlandica)
The Antarctic ice seals breed on ice. One of the most important food sources for these southern residents are krill. The crabeater seals teeth are designed to help filter krill from the water. There are no land based predators such as the polar bear or wolves to prey on these Antarctic seals. The leopard seal will prey on the other seal species when given a chance. Currently, all hunting of seals in Antarctica is governed by the Convention for the Conservation of Antarctic Seals (CCAS).
The Antarctica ice seals make up approximately 1/2 of the entire worlds population of pinnipeds. One of the reasons for this large number of seals is the remoteness of the Antarctic continent. It is really hard to get there. There are no humans close by to hunt the seals, and much of the time the sea ice helps protect some seals from other predators. Also, the seals of Antarctica eat krill, which is found in abundance in the waters surrounding the continent.
Click on one of the ice seal species to view information about them!
- Crabeater seals (Lobodon carcinophagus)
- Leopard seals (Hydrurga leptonyx)
- Ross seals (Ommatophoca rossii)
- Weddell seals (Leptonychotes weddellii)
The main difference between Arctic and Antarctic seals and open water seals is pupping (breeding) does not occur on ice. Open water seals do not have the sheets of ice to protect them from predators either.
The other seals of the world make up the smallest populations of seals. They have the most predators and are in contact with pollution throughout their lives. These seals are also more likely than their polar cousins to be struck by boats and ships. Some have even been struck on land by cars. All their food sources are impacted by contact with humans. Pollution is a major threat in the water they inhabit. Commercial fishing does not just impact the fish the seals eat, but the fishing nets and other gear are a major source of mortality for these open water seals.
Click on one of the seal species to view information about them!
- Harbor seal (Phoca vitulina)
- Northern elephant seal (Mirounga angustirostris)
- Baikal seal (Phoca sibirica)
- Caspian seal (Phoca caspica)
- Gray seal (Halichoerus grypus)
- Hawaiian monk seal (Monachus schauinslandi)
- Mediterranean monk seal (Monachus monachus)
- Southern elephant seal (Mirounga leonina)
This portion of the NMML website is intended for a student audience and their educators.
Information within the education website should not be cited in scientific journals or publications.