Scientists participating in the international Census of Marine Life have tallied an average of 10,000 known marine species in each of 25 important ocean zones, and discovered 1,200 new species, ScienceNews.org reported this week.
Researchers say Australian and Japanese ocean waters, each with about 33,000 species, top the list for highest diversity among the 25 regions surveyed, and the Gulf of Mexico, surveyed before the oil spill, ranked in the top five with 15,374 species.
The seas around China and the Mediterranean Sea were also high in biodiversity.
The census identified the biggest threats to sea life, with overfishing being the most serious, followed by habitat destruction from coastal development, pollution, trawling and other human activities.
The census gives "the first integrated look at the diversity and distribution of life in the oceans," marine ecologist Daria Siciliano of Sea Web in San Francisco said.
"In the wake of an oil spill in U.S. waters that is likely the worst environmental disaster in history, I hope the public is more likely to pay attention to what happens to the oceans," Siciliano said.