Global IssuesCLIMATE CHANGE: Seals in the Baltic Left without Ice
Ringed seals in the Baltic Sea are finding fewer and fewer ice caves in which to raise their young. Rising global temperatures are the problem, and in turn are depleting the main food source of the giant polar bear, say scientists.
Ever since the film 'An Inconvenient Truth' showed a polar bear swimming towards a solitary and fragile ice floe, the endangered species has become a symbol of the consequences of climate change.
That scene from the documentary film that made former U.S. vice president Al Gore even more famous actually used a computer-animated polar bear. However, its message is in keeping with the predictions of many researchers: the polar bear (Ursus maritimus) is in grave danger.
The World Conservation Union (IUCN) categorises the polar bear as 'vulnerable' and considers climate change its main threat, particularly because the melting of the polar ice cap, the bear's habitat, also reduces the availability of its food.
Their main food source is seals, including the ringed seal (Pusa hispida), whose habitat stretches from the Arctic regions to the Baltic Sea.
According to the latest report from the World Wildlife Fund (WWF), the near total ice melt in some parts of the Baltic, especially the gulfs of Bothnia and Riga, and the Åland archipelago, threatens the survival of the newborn seals there.
The Gulf of Bothnia, located between Sweden and Finland, is the northernmost region of the Baltic. The Gulf of Riga is found between Latvia and Estonia. The archipelago of Åland, part of Finland, is made up of 6,500 islands, also set between Sweden and Finland.
'Ringed seals give birth in mid-February and raise their pups in the first seven or eight weeks in caves formed on floating ice, while the pups put on enough fat to survive the icy ocean waters,' the WWF's Baltic Sea biodiversity expert, Cathrin Münster, told Tierramérica.
'The lack of ice around the Åland islands and in the Gulf of Riga means that the seals born this winter don't have that protection and surely will not survive,' she added.
With a weakened or insufficient ice field to sustain them, the seal pups are forced to swim in the frigid waters without the vital protection of a layer of fat, and they die of hypothermia and malnutrition.
In the early 20th century, the ringed seal population of the Baltic Sea was 180,000. Currently, according to WWF estimates, there are just 7,000 to 10,000 seals.
'During the past century, hunting and pollution have decimated the Baltic seal population,' said Münster. In recent years, as in the case of the polar bear, the seals' biggest enemy is climate change.
In Åland and Riga there are about 1,700 seals. This means the melting of the ice threatens the survival of nearly 25 percent of the total species population in the Baltic.
The recently concluded northern hemisphere winter was the second consecutive winter with a high mortality rate of seal pups resulting from a lack of sea ice. In the 2007-2008 winter, most of the newborn pups died in three of the four Baltic regions they inhabit.
The German federal ocean navigation agency, BSH, reports that the melt last winter in the Baltic was the greatest recorded in nearly 300 years, since measurements were first taken in 1720.
According to BSH, in the entire past century, save the winter seasons of 1960-1961 and 1988-1989, the Gulf of Bothnia remained completely frozen in February and until the middle of March.
But in recent winters, the melt has been so rapid that by mid-March the ice mass is as small as it is in December.
Estimates by the Meteorological Institute of Finland confirm this: the Baltic ice field in February stretched over 105,000 square kilometres. Although that area is twice that of the previous winter, it is just 25 percent of what it was in 1985, the coldest winter in the region's history, when the ice covered 400,000 square kilometres.
Münster believes the massive deaths of Baltic seals are both an announcement and a consequence of climate change. 'Without ice, the ringed seal, like many other species in the northernmost regions, cannot survive,' she said.
The seal pups need at least 90 days on the ice to survive. Furthermore, the ice floes must be extensive and thick enough to ensure the protection of the newborns.
Projections made by several entities, especially the Intergovernmental Panel on Climate Change (IPCC), warn that if the planet's mean temperature increases by more than two degrees Celsius in the next decades, by the end of the 21st century the volume of ice at the North Pole and surrounding regions could shrink by up to 80 percent.
The melting of the ice fields will mean that during the Baltic winter there will only be enough ice for the survival of the seals for a maximum of 50 days, said Münster.
(*This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Programme and the World Bank.)
© Inter Press Service (2009) — All Rights ReservedOriginal source: Inter Press Service