Representing the most comprehensive and authoritative answer yet to one of humanity’s most ancient questions -- “what lives in the sea?” -- Census of Marine Life scientists today released an inventory of species distribution and diversity in key global ocean areas.

Scientists combined information collected over centuries with data obtained during the decade-long Census to create a roll call of species in 25 biologically representative regions -- from the Antarctic through temperate and tropical seas to the Arctic.

Their papers help set a baseline for measuring changes that humanity and nature will cause.

Published by the open access journal PLoS ONE, the landmark collection of papers and overview synthesis will help guide future decisions on exploration of still poorly-explored waters, especially the abyssal depths, and provides a baseline for still thinly-studied forms, especially small animals.

Australian and Japanese waters, which each feature almost 33,000 forms of life that have earned the status of “species” (and thus a scientific name such as Carcharodon carcharias, a.k.a. the great white shark), are by far the most biodiverse. The oceans off China, the Mediterranean Sea and the Gulf of Mexico round out the top five areas most diverse in known species.

In a prelude to the ultimate summary of the landmark, decade-long marine census, to be released Oct. 4 in London, national and regional committees of the Census compiled the inventory of known and new species in the 25 key marine regions.