Here are 9 threats to the survival of the harp seal species.
Historic Hunting
Until recent decades, the harp seal was severely over-hunted. Native peoples of the Arctic regions hunted the seals sustainably for thousands of years. However, between 1600 and 1850, hunting increased from a few hundred seals per year to nearly 1 million per year. This ongoing masacre brought the harp seal to the brink of extinction.
Modern Hunting
Modern seal hunting has harmed, and continues to harm, harp seals. In 1983, the European Economic Community banned the import of whitecoat pelts, or baby seals, and the Canadian government banned whitecoat slaughters in 1987. Nevertheless, modern sealing threatens harp seals. From 1999-2003, the estimated annual mortality of harp seals in the Northwest Atlantic was 453,962, which is not sustainable. Harp seals are still slaughtered for their pelts, as well as their oil, which is now a trendy nutritional supplement.
Fishing Threats
Harp seals are sometimes unintentionally caught in nets designed to capture fish. When this happens, the seals may drown or die of strangulation. Alternatively, fishermen may simply kill the seal on site instead of attempting to handle or release a frightened 400-pound animal. Despite regulations to create fishing nets that are safe for dolphins, seals and sea turtles, accidents do happen and these do threaten harp seals.
Starvation
Fishing also threatens harp seals in other ways. The over-harvest of capelin, herring and other harp seal prey animals has led to starvation and malnutrition in wild harp seals. Many harp seals are now leaving their native ranges within the Barents and Greenland seas due to the collapose of herring and capelin populations. This has led the animals to move to areas in which they are not native-- an ecological problem that may be catastrophic for other native animals.
Climate change is one of the biggest threats to harp seal populatons. Global warming has led to changes in the amount of ice covering the harp seal's range, and this threatens the livlihood of many arctic species, including polar bears and harp seals. A harp seal depends on sea ice for giving birth, moulting and resting. Changes in sea ice can prevent them from readily engaging in these activities, and this can threaten the species' survival.
Oil Spills
There have been several oil spills in the last several decades affecting the habitat of the harp seal. Conservationists are concerned about the amount of tanker traffic in Lancaster Sound, which is critical for the survival of harp seals during the summer time. An oil spill in 1969 caused the death of tens of thousands of harp seals, and another similar catastrophe could be far more serious. For this reason, most environmental groups oppose the drilling of oil in the Barents Sea, which is ongoing and poses a serious threat to the species.
Pollution
Pollution
Harp seal blood contains massive amounts of pollutants including mercury, lead, DDT, PCBs and chlorine. These contaminants can cause birth defects, infertility, neurological problems, coma, aggression, poor coordination, cancer and liver failure in harp seals. The only way to prevent these problems is to eliminate sources of these pollutants through international regulation.
Viral Infection
Several viral infections, including phocine distemper virus and toxoplasmosis, have been causing disease and death within harp seal populations. The effects of these diseases are not fully understood, but they may cause serious problems if anthropogenic intervention perpetuates their spread. For example, the toxoplasmosis virus has entered our oceans because people have flushed cat feces down their toilets and it eventually spreads to the range of the harp seal. Proper sewage treatment and waste disposal could prevent these problems.
Natural Predators
Killer whales, polar bears and the Greenland shark all eat harp seals. Nearly one-fifth of a polar bear's diet is comprised of harp seals. Natural predation does not usually affect a species' long-term survival, but manmade problems such as global warming and overfishing may cause the predators to depend more on harp seals as a primary source of nutrition.