After 10 years of work, a team of 360 scientists worldwide studying everything from the tiny algae to the largest whale has concluded that there are some 230,000 known species inhabiting the earth’s oceans, and another million or so as yet undiscovered.
“Part of what this census has achieved is recognizing the magnitude of what we don’t yet know,” said Sylvia Earle, an oceanographer with the National Geographic Society in Washington, DC.
Their initial findings were released yesterday in Washington, DC. A more complete account will be released Oct. 4 in London.
Among their findings, the waters off Australia and Japan are the most diverse, home to about 33,000 named species each, with China, the Gulf of Mexico, and the Mediterranean Sea next in line.
Crustaceans and mollusks are the most common and widespread of the known species, while the vertebrates such as whales, seals, sea birds, and turtles, are among the least numerous, being lumped together in the 2% “other” category.
The purpose of the census was to create a baseline of information to help future research.
“This inventory was urgently needed for two reasons,” said Mark Costello of the Leigh Marine Laboratory in Auckland, New Zealand. “First, dwindling expertise in taxonomy impairs society’s ability to discover and describe new species. And secondly, marine species have suffered major declines – in some cases 90% losses – due to human activities and may be heading for extinction.”
Some of the major threats to ocean life identified in the census include overfishing, habitat loss, pollution, and invasive species. And there are more recent threats developing, as well, including rising water temperatures, acidification, and a growing number of areas with low oxygen.