Print

Mail

wiki links

Ocean census reveals unusual creatures

A photo released by the Census of Marine Life shows an Asbestopl, a new species of carnivorous sponge, about 1cm in diameter. It is one of four such species, three of them new to science, found in the Southern Ocean abyss by the Census of Marine Life, which is conducting a 10-year global survey funded by the Sloan Foundation. PHOTO: AP

An unprecedented audit of the oceans has discovered hordes of unusual creatures, forcing scientists to rethink their ideas about the world's wildest marine life.

Among the organisms to be identified are tiny carnivorous sea sponges that engulf passing prey with their mouths and single-celled animals that protect themselves by building football-like shells.

The species were spotted by two separate expeditions that set out to probe the little-known depths of the South Atlantic and Southern oceans.

Scientists aboard the vessels say that up to 90 percent of the creatures they encountered have never been seen before.

The expeditions were part of an attempt to draw up a census of life in the world's oceans, the most under-explored environment on Earth. Now at the halfway stage, the ?500 million (US$886.7 million) Census of Marine Life involves 1,700 scientists in 73 countries.

Each week, they add two new species of fish to a database that includes mammals, sea birds, corals, turtles and anemones. Along the mid-Atlantic ridge researchers spotted swimming red sea cucumbers, while in the Arctic ocean they discovered red jellyfish that grow up to 3m long.

Other creatures detected included a copepod, a shrimp-like crustacean and a jellyfish in the depths of the Canada basin far beyond its known range. The census now totals more than 40,000 species, including 15,717 fish, although researchers believe this is merely the tip of the iceberg.

"We estimate there are around 230,000 species down there and we want all of those documented by the end of the census in 2010. But that's a conservative estimate. We could well find a million new species by then," said Ron O'Dor of Dalhousie University in Canada and leading researcher on the census.

Biologists also looked for life near the epicenter of the earthquake that triggered the tsunami off Sumatra on Dec. 26 last year. Around the earthquake zone, there was little sign of any serious damage to wildlife, but closer by they found a dead zone where 11 hours of dives found no evidence of the large marine animals usually found in the region. Some smaller organisms such as the sea cucumber were also missing. According to the researchers, the absence of life was "unprecedented."

Key to the census is a silent-running vessel called GeoSars which carries the world's most sensitive sonar. The ship can detect creatures the size of a shrimp at a depth of 3km. The average depth of the oceans around the world is about 4km, giving the ship access to all but the deepest waters.

While some scientists focus on auditing species, others have implanted transmitters into fish and other creatures to track their movements. One bluefin tuna tagged with a transmitter stunned scientists by making three crossings of the Pacific Ocean in 600 days.
This story has been viewed 2788 times.