A marine census released on Monday has documented 7,500 species in the Antarctic and 5,500 in the Arctic, including several hundred that researchers believe could be new to science, as it looks like the polar oceans are not biological deserts after all. Even if many thought there is less diversity at the poles than at the tropics, researchers found astonishing richness of marine life in the Antarctic and Arctic oceans.

They found dozens of species common to both polar seas, separated by nearly 11,000 kilometers, but they have got to figure out how they managed to get separated. Most of these new discoveries were simpler life forms, known as invertebrates, or animals without backbones. For example, researchers found scores of sea spider species and shrimp-like crustaceans in the Arctic basin, which live at a depth of 3,000 meters.

The Census of Marine Life supports this survey, in an international effort to catalog all life in the oceans. The 10-year census is scheduled for final publication in 2010 and is supported by governments, divisions of the United Nations and private conservation organizations. It included over 500 polar researchers from 25 countries and took place during International Polar year which ran in 2007-2008.

Of course, the job wasn’t easy, as they had to endure 16-meter waves on their trip to the Antarctic. Furthermore, their colleagues in the Arctic worked under the watchful eye of a security guard hired to protect them from polar bears. However, technology made itself useful, as researchers used cell-phone-like tracking devices to record the Arctic migration of narwhals, a whale with a long twisted tooth, and remotely operated submersibles to reach several kilometers down into the oceans to study several species impossible to collect.

At the end, researchers counted and announced that they have discovered about 235 species in both polar seas, including five whale species, six sea birds and nearly 100 species of crustaceans. Even if they are separated by great distances, it’s clear for everyone that the Arctic and Antarctic are similar habitats. Researchers will now determine how long these species have been separated and if they have drifted apart genetically. They also think the species may have traveled along the deep-sea currents that link the poles or may have thrived during the height of the last ice age.

This is not the only project based in the polar oceans. The International Polar Year, organized by the International Council for Science and the World Meteorological Organization has been a scientific program focused on the Arctic and Antarctic from March 2007 to March 2009. Several thousand scientists from 60 nations conducted more than 200 projects. As for this one, it remains to be seen if researchers will manage to find out how the species got separated.