Census of world's sea life tallies up tentacles of surprises

— -- A shark playground, a mountain of sea stars, and octopi revealing an unsuspected Antarctic ancestry are among the mysteries unveiled in the latest worldwide efforts, released Monday, to draft a census of all sea life.

At the World Conference on Marine Biodiversity in Valencia, Spain, which begins Tuesday, researchers will discuss the "Census of Marine Life" update report. It details efforts by more than 2,000 scientists from more than 80 nations to account for all the species in the world's oceans by 2010.

"We're in the home stretch," says project senior scientist Ronald O'Dor. "Not to say someone won't pull up a giant squid from somewhere unexpected, but we think we are going to have a very good census."

Since 2000, the initiative — executed by boat, tags, nets and submarine — has uncovered more than 5,300 new species, as diverse as blind lobsters and sulfur-eating bacteria. Among the highlights:

• The deepest hydrothermal vents, 21/2 miles beneath the Atlantic Ocean, are thronging with species of shrimp and mussels.

• Great white and other sharks head to a previously unknown offseason Pacific region, perhaps to mate.

• Tens of millions of brittle sea stars were discovered tip-to-tip on an undersea mountain in the Antarctic Ocean.

• Combined genetic evidence from deep-sea octopi shows that many newer species evolved from a predecessor living in shallow Antarctic waters about 30 million years ago.

The researchers say changes in the ocean driven by a warming climate, overfishing and environmental damage add urgency to their effort. Moreover, the oceans remain by some estimates 95% unexplored, which makes them rich with discoveries.

"The more we look, the more we find," says molecular biologist Mitchell Sogin of the Marine Biological Laboratory in Woods Hole, Mass., who heads census efforts to profile marine microbes. Microbes total perhaps 90% of ocean life, he says, and they help keep the Earth habitable by cycling oxygen and carbon into the atmosphere.

"I would say we are in a second Golden Age of marine biology," says project scientist Patricia Miloslavich of Venezuela's Universidad Simón Bolívar, comparing today's efforts with those of earlier naturalists such as Charles Darwin and Carl Linnaeus, who first set out to catalog species. "I hope it doesn't end."