November 10, 2008
Ocean Study Finds New Wonders
Researchers found many of the world's deep-sea octopuses evolved from a common ancestor that still exists in the icy waters of the Southern Ocean.
A project called the, "Census of Marine Life" is trying to map the oceans; it started in 2000 and involves more than 2,000 scientists from 82 nations. The first CoML will be completed in 2010.
"We are approaching a picture of the oceans ... from microbes to whales," said Ron O'Dor, co-senior scientist of the census of the 2007-08 findings.
The research into the evolution of deep-sea octopuses was part of a program called the Census of Antarctic Marine Life (CAML), explained O'Dor.
"Many of these octopuses were collected from the deep sea by a number of the CoML's different projects."
"All of that material was brought together and made available to Dr Jan Strugnell, a biologist at the British Antarctic Survey (BAS) in Cambridge, and she used this material to carry out DNA studies.
Strugnell studied the octopuses and how they originated.
"She has been able to trace the timeline for their distribution back 30 million years to a common ancestor."
The species were traced back to a shallow-water octopus called Megaleledone setebos, which is found in the Southern Ocean.
The CoML has identified 5,300 likely new species, of everything from fish or corals. So far, 110 have been confirmed as new.
The report said octopuses apparently spread around the world after Antarctica became covered with a continent-wide ice sheet more than 30 million years ago, a shift that helped create oxygen-rich ocean currents flowing north.
"Isolated in new habitat conditions, many different species evolved; some octopuses, for example, losing their defensive ink sacs -- pointless at perpetually dark depths," the census said.
Researchers say mapping the oceans is helping them protect marine life from threats including over-fishing, pollution, and climate change.
During the census, scientists found algae thriving in Arctic waters of -25 Celsius, kept from freezing because salt concentrations were six times more than in normal sea water.
Researchers found anemones, worms and shrimp in the mid-Atlantic around the world's deepest known active hot volcanic vent, over 4,100 meters deep.
The discovery of a wealth of new species was not a sign that the oceans were healthier than thought.
"The things that we're discovering ... are not the kind of things you want to see on your plate very often," O'Dor said.
The fourth update of the census was released Sunday ahead of a meeting of hundreds of researchers that begins Tuesday in Valencia, Spain.
Dr O'Dor said that the main focus of the CoML for the remaining two years was to "synthesize" the data.
"Many of our projects have already completed their fieldwork and we have a lot of information," he observed.
"What we are now trying to do is to bring all that information together in a form that allows the public to understand how much we have learned about the ocean and what lives in it."
Image Caption: Megaleledone setebos, a shallow-water circum-Antarctic species endemic to the Southern Ocean. It is the closest living relative to the clade of deep-sea octopuses. The specimen shown is a juvenile; adults reach a total length of nearly 1 meter. Credit: M. Rauschert
On the Net:
- Census of Marine Life
- Census of Antarctic Marine Life
- Scientists Report Major Steps Towards 1st Census of Marine Life (PDF)