A huge, ice-covered pool believed to hold the world’s oldest seawater is being scoured by scientists taking an inventory of aquatic life in the Arctic, the least-documented ocean on the planet.
A small sampling for the inventory, financed by a $600,000 grant from the Alfred P. Sloan Foundation announced Thursday, has already found at least five new species as well as creatures previously unknown to the two-mile-deep Canada Basin, located north of Alaska and the Yukon Territory.
Many species in the basin’s chilled depths are thought to have lived in isolation for millions of years. Through the inventory, biologists, physicists and geologists from more than 50 countries hope to learn more about the genetics of species that can survive in such extreme conditions.
Researchers say a melting polar ice cap gives urgency to the project, part of a decade-long, $1 billion global survey called the Census of Marine Life. The census also is planning to inventory the Antarctic Ocean and Earth's other oceans.
Past studies have yielded a surprisingly diverse collection of species — about 5,000 known multicellular ones — that live in Arctic waters, according to researchers.
“It is certainly not the desert people thought it to be,” said Russ Hopcroft, a marine ecologist at the University of Alaska Fairbanks, the project headquarters. “This is the world’s refrigerator where change has happened far more slowly than in other oceans.”
Climate change concerns
“We need to begin paying more attention to biodiversity in the Arctic, which is more vulnerable to climate change because of its multiyear ice cover,” Hopcroft said. “There are animals here that are uniquely adapted to that ice cover. If the Arctic continues to lose ice each summer, these animals could become extinct, not to mention overall changes.”
The Canada Basin is a mystery because it is cut off from deep waters in the Pacific by the 210-foot deep Bering Strait and from currents from the more distant North Atlantic by 4,200-foot deep ridges and straits.
“This water has been isolated more than any other part of the world’s oceans, including around Antarctica,” said Bodil Bluhm of the University of Alaska.
Since the mid-1970s, the winter ice pack in the Arctic has decreased 2 percent to 3 percent each decade, said Rolf Gradinger, a University of Alaska sea ice ecologist participating in the study. Scientists say that without large ice masses, which reflect the sun’s rays into the atmosphere, the earth absorbs more heat, contributing to further warming. Ice also serves as a platform for walrus and seals.
“When the ice cover disappears, you lose an important environment,” Gradinger said. “Changes in sea ice produce a domino effect.”
Researchers also plan to look at the mouths of rivers in Russia and Canada that pour an estimated 2 trillion tons of fresh water into the Arctic Ocean each year. Climate change could bring more runoff, changing species composition. U.N. models say that Arctic summers could be largely ice-free by 2100 because of global warming.
Fear of invasive species from shipping
Among challenges facing the Arctic project are finding and paying for the use of ice breakers, usually scheduled at least two years in advance, researchers said. August trips are planned, however, on Russian and Canadian vessels already scheduled for unrelated endeavors.
Political boundaries can also complicate access to some areas. Seafloor sampling and imaging "can be a ‘hot’ issue in regions valued for their underground resources or those known or suspected for dumping of nuclear and other wastes,” the researchers said in a statement.
Ron O’Dor, chief scientist of the census, speculated that Arctic waters might hide creatures known only from fossils, such as trilobites that flourished 300 million years ago. The trilobites looked like over-sized modern woodlice.
He said it might find new types of jellyfish, giant squid or more humble plankton and algae. “And this may be a last window of opportunity to study the Arctic Ocean because of climate change,” he said.
More southerly species may invade Arctic waters if the polar icecap melts while increased shipping could accidentally introduce new creatures to the region in ballast water and disrupt the pristine ecology, he said.