(LONDON) -- How many fish are there in the sea? Scientists would not dare guess, but they estimate, in the first-ever Census of Marine Life announced Monday, that there are at least 250,000 known species in the world's oceans, from the tiniest single-celled creatures to the most massive blue whales.
It took a decade of work, with 2,700 scientists from 80 countries spending 9,000 days at sea on 540 separate expeditions. Their work was financed by foundations, universities and the governments of the researchers.
The purpose of the census was to establish a baseline -- a cross-section of marine life worldwide -- so that as things change, scientists will not have to speculate just how. Future scientists doing research on climate change, pollution, or shifts in the composition or acidity of sea water in particular parts of the world will have an idea of what lived there back in 2010.
On the way to assembling their database, the researchers came back with remarkable pictures of just a few of the 120,000 species they directly studied. Even after all the work that went into the census, the organizers say another 750,000 species may still be not be catalogued.
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