The Census of Marine Life[1] has now documented 7,500 species from the Antarctic and 5,500 species from the Arctic. A majority of the species encountered by the census was previously known by science, but at least a few hundred species are believed to be entirely new discoveries. Researchers did for instance encounter an impressive amount of sea spiders species where the adult spider can grow as big as a human hand.

These new findings may force us to change the way we think about the Polar Regions. “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,” says Dr. Victoria Wadley[2], a researcher from the Australian Antarctic Division who took part in the Antarctic survey. “We are rewriting the textbooks.“

Dr. Gilly Llewellyn[3], who did not take part in the survey but is the leader of the oceans program for the environmental group WWF-Australia, agrees. “We probably know more about deep space than we do about the deep polar oceans in our own backyard. This critical research is helping reveal the amazing biodiversity of the polar regions.”

The survey was carried out by over 500 researchers from 25 different countries as a part of the International Polar Year which ran in 2007-2008. Thanks to newly developed top-notch technology it is now possible to carry out more efficient exploration of these harsh environments than ever before, and the researchers did for instance examine the Arctic basin down to a depth of 3,000 metres where they encountered tiny, shrimp-like crustaceans. The survey also led to the number of known comb jellies (ctenophores) species to double from five to ten.

Hundreds of new animal species have been discovered by marine researchers studying Australian reefs as a part of the Census of Marine Life, an international effort to catalogue all life in the oceans. The findings include such curious creatures as tongue-eating isopod parasites living on fish and several new species of tanaid crustaceans, some with claws longer than their bodies. The team also found about 150 species of soft coral thought to be new to science, scores of tiny amphipod crustaceans of which an estimated 40 to 60% will be formally described for the first time, and dozens of small crustaceans likewise believed to be unknown to the scientific community. Researchers actually suspect that one or even several new families of species are to be found among the sampled crustaceans.

The investigated locales are the Lizard and Heron Islands (part of the Great Barrier Reef), plus the Ningaloo Reef off north-western Australia. All locations are considered well known and popular among scuba divers, and the research team was therefore quite surprised when they stumbled upon such a prolific collection of species unknown to science. This shows how little we still know about the species that inhabit our planet; even the ones living in habitats frequented by hundreds or even thousands of people each year.

Map of locations

“People have been working at these places for a long time and still there are literally hundreds and hundreds of new species that no one has ever collected or described,” says Julian Caley, a scientist from the Australian Institute of Marine Science who is helping to lead the research. “We were all surprised and excited to find such a large variety of marine life never before described – most notably soft coral, isopods, tanaid crustaceans and worms – and in waters that divers access easily and regularly. Compared to what we don’t know, our knowledge of marine life is a proverbial drop in the ocean. Inventorying the vast diversity and abundance of life across all ocean realms challenges both science and the imagination.”

In order to aid future explorations, researchers left several “houses” – formally known as Autonomous Reef Monitoring Structures (ARMS) – for marine creatures to colonize on the ocean floor. The houses consist of layered plastic structures and have been designed to appeal to a variety of sea life. Over the next one to three years, the houses will be collected and their tenants investigated.

See pictures of some of the creatures here

The Census of Marine Life (www.coml.org) is a global network of researchers in more than 80 nations engaged in a 10-year initiative to assess and explain the diversity, distribution, and abundance of marine life in the oceans – past, present, and future. The network will release the first Census of Marine Life in 2010.