The commercial hunting of seals is controlled in many parts of the world by law and international treaty for purposes of conservation. Many species may not be hunted at all; others are protected except for an occasional period of culling (selective hunting). In the case of thriving species, hunting is generally confined to killing bachelor bulls, yearlings, and pups, so as not to interfere with breeding.
Pelagic sealing—the killing of seals at sea, where it is impossible to distinguish between bulls and cows—has been largely eliminated. Seals are usually hunted at their rookeries, where bachelor bulls occupy a territory separate from the harem bulls and their families. The seals are commonly clubbed or shot to death and the carcasses dressed on the spot, in order to take the blubber, the skin, or both.
Ringed seals, Caspian seals, and South African fur seals are among the most commonly hunted species today. Harp seals were killed in large numbers until 1983, when what is now the European Union banned the import of their pelts.
In the past, certain pinnipeds were in danger. Some, like the harp seal, were overhunted for their fur. Pinnipeds were also hunted for food, oil, and skins.
Seals have few natural enemies. They may fall prey to whales and sharks in the water. On ice, polar bears are their biggest threat. But, people create the biggest dangers faced by pinnipeds. People diminish their food supply. People make the waters pinnipeds swim in dangerous. So, only people can protect these animals.
Hawaiian and Mediterranean monk seals are still endangered (there are so few of them, they might become extinct). So are Northern sea lions (sometimes called Steller’s sea lions). The Caribbean monk seal has already become extinct (meaning all the animals of that kind have died).
As people became aware that entire species were becoming extinct, they passed laws to protect the animals, including pinnipeds. Over time, these laws have helped more pinnipeds to survive.
The earliest known instance of organized sealing occurred along the Barbary Coast of Africa, where the Mediterranean monk seal was hunted for its skin in the 15th century. By the end of the 18th century, explorers had discovered most of the major seal herds in the world, and sealing, for blubber and skins, grew into an important industry. In the early 19th century the slaughter reached such proportions that one species, the Philippi fur seal, became extinct. When seals had grown so scarce that the industry itself almost died, protective measures began to be taken.
In 1911 an international treaty outlawed pelagic sealing of northern fur seals, which had almost become extinct. Large numbers of northern fur seals continued to be hunted on the Pribilof Islands until 1985. Since then, they have been hunted only by the Aleuts, for their own food supply.
Other species, including the elephant seals and some southern fur seals, have also received protection from international treaties. In the United States, the Marine Mammal Protection Act of 1972 prohibited most hunting of seals.
When a pinniped is hauled out, it’s easy for scientists to observe its behavior. Scientists have watched pinnipeds haul out to rest and warm themselves. Scientists have watched pinnipeds give birth, care for their young, and molt. Scientists have even observed pinnipeds escaping from enemies.
But there is still a lot that scientists do not know about pinnipeds. It’s hard to observe these animals when they are not hauled out. So we do not know much about their habits at sea.
Scientists have, however, found ways to track these animals. They have attached time-depth recorders and radio transmitters to some seals. These tell where the seals swim and how deep they dive. By using these devices with satellites, scientists hope to learn even more about pinnipeds at sea.