04/07/2009 - In 1959, a dozen nations agreed on the peaceable use of the Antarctic subcontinent "forever" and "in the interests of all mankind"—a landmark pact that created the Antarctic Treaty System. This agreement marked the first cooperation between the United States and the Soviet Union during the Cold War.
Now, however, the combination of global climate change and new fishing technology threatens the Antarctic and many of the species that call it home—including krill, the bedrock of the Southern Ocean food chain.
As diplomats and scientists gather in Baltimore for consultative meetings and to celebrate the treaty's 50th anniversary, however, they have a unique opportunity to collaborate on new measures that could ensure the health of the Antarctic ecosystem for decades to come. While they lack the prominence of penguins and other creatures in the public eye, krill have attracted scientific attention for some time.
Serving as perhaps the most crucial part of the Antarctic food web, these shrimp-like crustaceans act as nature's link between plants and larger animals such as seals, penguins and whales. Indeed, many of these large animals rely on krill as their primary or sole source of nutrition. Yet, while krill form the largest biomass of any species under the sea, they have recently seen steep declines. According to an analysis of data from over 40 summer seasons, Antarctic krill densities off the Western Antarctic Peninsula have dropped roughly 80 percent since 1976. While a number of factors may have contributed to this dangerous trend, global warming has imposed a particularly harmful set of effects.
As temperatures rise, ocean circulation suffers, hindering upwellings—the natural flip-flop of waters that brings to the surface the deep-sea nutrients required by plants and algae. Such microscopic plants fuel krill populations, and without those upwellings krill have less to eat and populations suffer. Another source of nutrition for krill has been the algae that grow under sea ice, just as plants on land grow in soil. These large areas of sea ice also act as "safe harbors" for krill, sometimes housing five times as many of the small crustaceans as open water. But because sea ice is thawing as a result of climate change, krill's pantry threatens to grow increasingly bare.
Nor is global warming the only problem facing krill populations.
Commercial fishing companies have begun casting their eyes toward krill, which are rich in the omega-3 fatty acids used in aquaculture fish feed and nutritional supplements for people. In the past, it was comparatively easy to harvest krill while keeping the populations viable. But recently, commercial fishing engineers have achieved a new level of exploitative efficiency with the vacuum trawler. While the world's entire commercial krill fishing fleet harvested about 100,000 tons of krill two years ago, today one new vessel might extract that quantity by itself in a single year. Although only one vacuum ship currently operates, the commercial fishing industry has its sights set on expansion.
Fortunately, in 1980 the member states of the Antarctic Treaty System formed the Convention for the Conservation of Antarctic Living Marine Resources to protect plants and animals in the Southern Ocean, especially krill. The month marks the first meeting, in Baltimore, of the scientific committees of the larger treaty system and the smaller protective body. In light of the important role krill play in the marine ecosystem, managing the Antarctic krill fishery should be at the top of the summit's agenda.
Just as they collaborated 50 years ago, setting aside their considerable differences for the greater good, member nations must now work together to establish stronger precautionary rules to conserve krill.
Safeguarding just this one species would provide a boon for the whole Antarctic ecosystem, including endangered penguins and whales.
Facing formidable opponents—increased harvesting capacity, a shrinking habitat and a dwindling food supply—these small creatures need to be protected before it is too late.
Gerry Leape directs the Antarctic Krill Conservation Project for the Pew Environment Group.