Bearded seal. Photo: NOAA
Many seal species depend on sea ice for their survival. As global climate change reduces the extent, duration, and thickness of sea ice, these seal species are threatened with extinction.
As global warming worsens, the (un)natural mortality rate of the harp seals worsens, too. Harp seal mothers need large, sturdy ice floes to give birth to their pups, and pups do not know how to swim for the first few weeks of their lives.
Bearded seals, like the one shown in the photo to the right are now listed as threatened, giving them extra protection in the U.S.
|Harp seals depend on sea ice for pupping. In the first weeks of life, seal pups can't swim. This seal pup was in trouble as the ice around it crumbled. Photo by IFAW.
Seals of the Arctic
Six seal species live in the Arctic region: bearded seals, harp seals, hooded seals, ribbon seals, ringed seals, and spotted seals. Bearded seals, harp seals, and ringed seals are especially vulnerable to disappearing sea ice.
Click on picture for larger image
Bearded seals and ringed seals give birth on dense ice packs or on "fast ice", ice usually located over shallow parts of the ocean that is 'fastened' to the ocean floor or shore', such that it does not drift in the wind. They also require snow cover on the ice to build lairs for giving birth.
Harp seals follow the sea ice all year, migrating south from the Arctic in the spring. The seals give birth off the coast of Norway and Newfoundland and Labrador, in Russia's White Sea, and in the Gulf of St. Lawrence of Canada. The pups begin life unable to swim. Thus they require sturdy sea ice during the birthing season in February and March.
Click on picture for larger image.
In recent years, thousands of harp seal pups have drowned due to insufficient and broken up sea ice. Unusually poor ice conditions have been reported in 2006, 2007, and each year from 2010 on.
In 2011, the ice floes were in very poor condition. The February 2011 ice cover was the worst in recorded history, but this did not stop the Canadian government (i.e., the Department of Fisheries and Oceans, DFO, led by Minister Gail Shea) from setting an astronomical quota on the killing of harp seal pups.
In the end, a fraction of these seals were killed as a result of the closing of pelt markets.
Read about the 2011 seal hunt here.
Read the latest news on seals and sealing in Canada here.
The animal protection organization IFAW worked with Duke University scientists on a study of the harp seal population and the current and projected future effects of climate change on the species. Read about the Duke/IFAW study here. A follow-up study investigated causes of harp seal strandings and found increased strandings of harp seal pups in years with poor sea ice. It also found that young males stranded more frequently than young females.
MEAT COVE — Poor ice conditions in the southern Gulf of St. Lawrence are likely to endanger this year’s harp seal pups. Cape Breton Post, March, 2011
Read the published report on the study about the effects of climate change on harp seals here.
Even the scientists of the Canadian Department of Fisheries and Oceans (DFO) have reported that the population is now in decline.
Harpseals.org believes that the future of harp seals is in peril and that it is high time that the government of Canada work to protect seals and ban the killing of seals once and for all.
Seals of the Antarctic
A Weddell seal
Four seal species live in the Antarctic: crabeater seals, leopard seals, Ross seals, and Weddell seals. Crabeater seals and Weddell seals give birth on sea ice and are thus at risk of exctinction as temperatures warm and the formation of sturdy sea ice becomes less reliable
Another threat to the survival of seals
In addition to the lack of sea ice, some species of seals and other marine mammals are threatened by reductions in the availability of prey. Prey populations are affected by climate change, over-fishing, and ocean pollution. A reduction in the abundance of plankton affects life up the food chain.
Click here for additional information and a pictorial description of predator-prey effects with grey seals.
Seals are an important part of the ocean ecosystem
Seal conservation is about far more than saving seals and stopping the Canadian seal slaughter. It is about saving marine ecosystems, of which all seals are an integral part.
Historical records from the time Europeans arrived in Newfoundland demonstrate that, without interference from these immigrants, seal populations much larger than that remaining today coexisted with cod so abundant that ships had difficulty maneuvering through the waters.
Today, conservation issues in the Arctic and North Atlantic region include the effects of large-scale commercial fishing, using such methods as bottom trawling and long-line fishing; global climate change, including changes in ocean currents, carbon dioxide concentration, and temperature; increased ship traffic as a result of decreases in sea ice; ocean pollution; and sealing.
The following are links to programs that may be of interest to those who wish to study marine ecosystems and marine mammal conservation:
Institute for Marine Mammal Studies
Woods Hole Oceanographic Institution
University of Miami Rosenstiel School of Marine and Atmospheric Science Marine Mammal Program
Other links to societies and graduate programs from the Society for Marine Mammology