The World Conference on Marine Biodiversity, meeting in Valencia, Spain, in mid-November, received the fourth report on the Census of Marine Life, which is being compiled by 2,000 scientists from 82 nations. It will be officially released in October 2010.

This report revealed some amazing new findings about life in the ocean depths. In a press release from the Valencia conference, scientists reported the first molecular evidence that a large proportion of deep sea octopus species worldwide evolved from a common ancestor species that still exist in the Southern Ocean. They believe octopuses began migrating to new locations when Antarctica cooled and a large ice sheet grew about 30 million years ago. The octopuses followed a “thermohaline expressway,” a northbound flow of sea water with a high salt density caused by the ice that forms at the surface around the Antarctic. In their new habitats, many species of octopuses evolved.

 This and other revelations into the global distribution and diversity of deep sea life was made possible by intensive sampling during International Polar Year expeditions, according to the census report, which also relied on studies from many other areas of the world’s oceans.  Among some findings from expeditions in the polar regions:  

–Scientists in the Alaskan Arctic found a site with a rocky seafloor, rare along the normally soft and silty Arctic coastline. The hard substrate hosts a diverse community compared to surrounding soft bottom habitat. Researchers also discovered new species in the Aleutian archipelago, including a kelp, sea anemones, chitons (small ocean mollusk), snails, and sea stars.

–Researchers studying life in the Arctic found temperatures of –25 degrees Celsius in sea-ice channels where brine is more than six times saltier than regular sea water. Representing the coldest conditions in the global ocean, the channels were home to sea-ice algae and flagellates thriving in concentrations of thousands of individuals per liter.

–In the Canada Basin of the Arctic Ocean, researchers found several new species and more than 50 categories of gelatinous zooplankton. The first new species formally described from the expedition was named Sigambra healyae, in honor of the research vessel, the U.S. Coast Guard Cutter Healy.

 –Scientists exploring a 10,000-kilometer (6,210-mile) portion of the Antarctic Weddell Sea, made accessible by the collapse of the Larsen A and B ice shelves, sampled an estimated 1,000 species. Of these, 15 potentially new amphipod (shrimp-like) species included one of Antarctica’s biggest-ever amphipod crustaceans, nearly 10 centimeters (3.9 inches) long. 

–Explorers made the first record of many marine animals in many areas of the Canada Basin. These included abundant and diverse comb jellies under Arctic pack ice and a dense bed of sea cucumbers. They also recorded more squid than ever before in the Arctic deep sea, and documented the importance of sea-ice ridges for marine life in the region.

–Expeditions to the Southern Ocean found frequent examples of gigantism common in Antarctic waters. The researchers collected huge scaly worms, giant crustaceans, starfish and sea spiders as big as dinner plates.

–Two new underwater robots gave scientists a bird’s eye view of what lives on Gakkel Ridge in the Arctic Ocean. These exploration vehicles carry cameras and sophisticated arrays of instruments that allowed scientists to discover a new underwater volcanic chain covered by extensive microbial mats. Because the deep Arctic ridges are isolated from other ocean basins, the investigation of Gakkel Ridge provides clues about the evolution of life around underwater vents in isolated habitats.

When the census is released in 2010, it is anticipated that an estimated 230,000-250,000 known species will be cataloged. Web pages will be available for the great majority of the named species, compiled in cooperation with the Encyclopedia of Life;

According to Ian Poiner, chair of the Census’s International Scientific Steering Committee and chief executive officer of the Australian Institute of Marine Science: “The release of the first Census in 2010 will be a milestone in science. After 10 years of new global research and information assembly by thousands of experts the world over, it will synthesize what humankind knows about the oceans, what we don’t know, and what we may never know – a scientific achievement of historic proportions.”

Find photos of several species in the census’s image gallery at http://www.coml.org/pressreleases/highlights08/index.html