February 16, 2009

Marine Census Yields Surprising Results

At least 235 species are thriving in both the Arctic and Antarctic polar seas, according to the Census of Marine Life.

Scientists found that species such as grey whales, birds, worms, crustaceans, and angelic snail-like pteropods exist at both poles. Dozens of species were separated by nearly 7,000 miles, they said.

Researchers are currently conducting DNA tests to prove whether or not the species are identical, and if so, they want to determine where the species "originated and how they wound up at both ends of the earth," they said.

Long seen as frigid barren regions, the two poles have eluded scientists, and the census' findings are turning previous notions upside down.

"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. "We are rewriting the textbooks."

The census involved 500 researchers from more than 25 nations, and took place during International Polar Year (from March 2007 to March 2009). They took data from nearly 1 million locations. Those places include seafloors exposed to light for the first time in as much as 100,000 years when ancient ice shelf lids melted and disintegrated in recent years. The findings will be included in the global Census of Marine Life report in 2010.

"We probably know more about deep space than we do about the deep polar oceans in our own backyard," Gilly Llewellyn, leader of the oceans program for the environmental group WWF-Australia, told the AP. She did not take part in the survey.

"This critical research is helping reveal the amazing biodiversity of the polar regions."

SCUBA divers were deployed for observations in heavy Arctic ice and advanced, deep water optical systems on Remotely Operated Vehicles (ROVs) enabled detailed studies of delicate marine animals too fragile to collect. Similar approaches recorded videos of penguins and seals under Antarctic ice.

Scientists also noted the discovery of several crustaceans and sea spider species living at a depth of 9,850 feet.

"The oceans are a mixing ground," Ron O'Dor, co-senior scientist of the census, told BBC News. "There are all kinds of currents that allow things to move around."

"There is continuity in the ocean as a result of the major current systems, which we call the 'conveyor belt'; a lot of these animals have egg and larvae stages that can get transferred in this water."

"The traditional approach was to describe an organism's physical features, so if these organisms lived in very similar habitats, did very similar jobs and ate similar food, then they often looked very alike even if they came from different origins," said O'Dor.

"So we are also working very closely with the Barcode of Life team at the University of Guelph (Canada), and we hope that by 2010 that we will have about 90% of marine species barcoded."

Scientists with the Census' project on Arctic Ocean Diversity noted a rising ratio of warm water to cold water-amphipod crustaceans in Hornsund fjord in Norway's Svalbard Island group. Additionally, they documented range extensions to the north of at least three species and a growing number of snow crabs. All of these findings are contributed to warming, they said.

"The polar seas, far from being biological deserts, teem with an amazing quantity and variety of life," said Dr. Ian Poiner, Chair of the Census Scientific Steering Committee.

"Only through the co-operation of 500 people from more than 25 countries could the daunting environmental challenges be overcome to produce research of such unprecedented scale and importance. And humanity is only starting to understand the nature of these regions."


On the Net: