AT HALFWAY MARK, 10-YEAR SEA CENSUS REVEALS LOTS OF SURPRISES
Mike Toner Cox News Service
19 December 2005
Carnivorous sponges, globe-trotting tuna and an eerie underwater "dead zone" at the epicenter of last year's tsunami are just a few of the surprises turned up in the first census of the world's oceans.
And more surprises may lie ahead. Having reached the midpoint of the unprecedented 10-year census, which involves scientists in more than 73 nations, researchers reported last week that the 230,000 marine species now known to science are only the tip of the iceberg.
"By the time the census is completed in 2010, we expect to have collected a million new species," said Ron O'Dor, the senior scientist for the international Census of Marine Life.
"One of our research vessels went to a site off the coast of Africa and discovered 400 new species of copepods [microscopic crustaceans] living in the sediment at the bottom of the sea," Mr. O'Dor said.
The pace of discovery is due in part to the fact that scientists, equipped with deep-diving robotic vehicles and new technology, are looking for life where few have looked before: abyssal plains two miles or more below the surface, polar seas and remote underwater mountain ranges.
"These regions of the ocean are the last, vast unexplored regions on the planet," said Mr. O'Dor. "But even if you wade 10 meters off the shore and pick up a handful of mud, you're likely to find something we didn't know about before," he said. "We didn't know what was there because no one was interested before now."
The goals of the 10-year, $1 billion series of programs, launched in 2000 with seed money from the Alfred P. Sloan Foundation, include an ambitious effort, dubbed "fish with chips," to implant tiny tracking devices in thousands of marine animals, large and small, and track them for years at a time.
By satellite, scientists are already tracking more than 21 species of fish, turtles and sea lions. They tracked one bluefin tuna as it made three crossings of the Pacific Ocean -- covering 25,000 miles in 18 months.
And an ambitious new network of acoustic sensors stretching along 800 miles of the continental shelf, from Washington state to the Alaska panhandle, is tracking salmon and other migratory fish as they move to and from rivers of the Pacific Northwest. The information compiled about marine migration may be valuable to both fishermen and biologists.
"We're not trying to put chips in every fish in the ocean, but the ocean used to be a black box that fish just disappeared into," said the project's chief scientist, David Welch of Malaspina University in British Columbia. "Now we can determine where they're going and when."
Most new species are likely to be very small -- no great surprise in an environment where 90 percent of the total living mass is microscopic.
At the halfway point of the census, however, the list of discoveries includes a number of noteworthy finds:
* In the South Atlantic and Southern oceans, three new species of carnivorous sponges that engulf other organisms with their mouths, rather than filter-feeding like most sponges.
* In the North Atlantic, four new species of sea cucumbers, sluglike creatures that live on the bottom; two possibly unknown species of squid; and several deep-swimming fish never seen before.
* In the Indian Ocean, a strange and unexplained "dead zone" seven miles long and more than three miles below the surface, near the epicenter of the December 2004 earthquake and tsunami where thick silt seems either to have destroyed all signs of life or driven it away.
"That area was very puzzling," said Paul Tyler of Britain's National Oceanography Center. "I've participated in over 100 dives, and I have never encountered a place on the ocean floor where there was absolutely no life visible -- no crabs, no starfish, no tubeworms, nothing."