It’s been a decade in the making and it has involved the efforts of 2,700 individuals from 80 countries and an investment of some $650 million, much of which was underwritten by the Alfred P. Sloan Foundation. While we have previously reported on the Census of Marine Life earlier in the year, the heavy lifting required of this monumental undertaking reaches completion.
As Nature News and other science media are reporting, its findings paint the clearest picture ever created to date both of what we know, as well as the magnitude of what we still do not, regarding the life that populates the world’s marine environments.
Described as the most comprehensive survey of marine life ever assembled, the findings of the 10-year study provide both a percentage breakdown of the different types of species that comprise global marine life while offering clearer understanding of the extent to which how much life may be found in the oceans varies among different world regions.
As Science Daily breaks it down for us, the Census finds that about one fifth of marine life are crustaceans (crabs, crayfish and krill for example), followed very closely by mollusks (such as squid, snails and slugs). At 12 percent of marine life are the world’s fish, followed by 10 percent each for single cell protozoans and algae. Coming in at lesser percentages below 10 are species classifications that include worms, anemones, corals, starfish and sponges.
The Census, whose findings are now published online at PLoS ONE in advance of the ceremonial official unveiling slated for October, determines that the greatest bounty of marine life diversity may be found in waters near Japan and Australia, which each exhibit more than 30,000 distinct species. The ocean off China as well as the Mediterranean Sea and the Gulf of Mexico were found to follow very closely in terms of richness of diversity. The study additionally finds that waters off Antarctica, New Zealand, South Africa and Australia are more likely to contain so-called endemic species that are to be found nowhere else.
Perhaps one of the more surprising conclusions drawn from such a vast, sustained effort is the shared sense by those involved of just how little we actually know. Nature News points out that the scope of the Census was limited to exclusive economic zones, marine areas that stretch 200 nautical miles from the shoreline. This continues to leave the open oceans, and what’s happening at great depths, an ongoing mystery. But even through a relatively close-to-shore focus, surprises and fresh discoveries abound thanks to the effort.
“One might have thought that these waters were well documented, but no,” observes Dalhousie University’s Ron O’Dor, Census of Marine Life senior scientist. “In fact, the papers’ authors estimated that, on average, there are three or four more species to be discovered for every one documented.”
Marine expert Sylvia Earle weighs in similarly: “One conclusion is that we have a lot more to learn about the ocean. A conservative estimate of ocean species is 10 million, and it may be 50 million or more. Less than 5 percent of the ocean has been seen, let alone explored.”
Photo by Julian Finn courtesy of Museum Victoria.
