A survey of the world’s oceans is turning up more than two new species of fish a week and has revealed the adventurous journeys creatures such as turtles and tuna make across the oceans.

The discoveries have been made by a project called Census of Marine Life, which brings together the work of hundreds of scientists in 70 countries.

The census’s senior scientist, Ron O’Dor, says the project started four years ago and has another six years to run.

“We’re finding new marine species almost everywhere,” he said.

The number of species is even climbing in well-studied waters like those off Europe.

The census will aid understanding of the oceans, the least-known part of the planet’s surface, and help in monitoring threats including over-fishing and global warming.

For fish alone, the census has turned up 106 new species so far in 2004, or more than two a week, according to a 2004 report.

The finds bring the known total of fish species to 15,482.

Among fish, new species found in 2004 include a type of striped goby that lives off Guam in the Pacific.

Other finds in 2004 included two types of octopus in chilly waters off Antarctica and a burrowing 20-centimetre worm, dubbed a “purple orchid”, in the depths of the mid-Atlantic.

The census estimates there are about 230,000 known species of marine life, mostly tiny microbes but ranging up to blue whales. It says the real number of species may top 2 million.

More here.