Study: 'Astonishing richness' in polar sea species

BANGKOK, Thailand -- The polar oceans are not biological deserts after all.

A marine census released Monday documented 7,500 species in the Antarctic and 5,500 in the Arctic, including several hundred that researchers believe could be new to science.

"The textbooks have said there is less diversity at the poles than the tropics, but we found astonishing richness of marine life in the Antarctic and Arctic oceans," said Victoria Wadley, a researcher from the Australian Antarctic Division who took part in the Antarctic survey. "We are rewriting the textbooks."

In one of the biggest surprises, researchers said they discovered dozens of species common to both polar seas — separated by nearly 7,000 miles (11,000 kilometers). Now they have to figure out how they separated.

"We probably know more about deep space than we do about the deep polar oceans in our own backyard," said Gilly Llewellyn, leader of the oceans program for the environmental group WWF-Australia. She did not take part in the survey. "This critical research is helping reveal the amazing biodiversity of the polar regions."

Most of the new discoveries were simpler life forms known as invertebrates, or animals without backbones.

Researchers found scores of sea spider species that were as big as a human hand, and tiny, shrimp-like crustaceans in the Arctic basin that live at a depth of 9,850 feet (3,000 meters).

The survey is one of several projects of the Census of Marine Life, an international effort to catalog all life in the oceans. The 10-year census, scheduled for final publication in 2010, is supported by governments, divisions of the United Nations and private conservation organizations.

The survey — which included over 500 polar researchers from 25 countries — took place during International Polar Year which ran in 2007-2008.

Researchers endured up to 48-foot (16-meter) waves on their trip to the Antarctic, while their colleagues in the Arctic worked under the watchful eye of a security guard hired to protect them from polar bears.