Australian and Japanese waters, which each feature almost 33,000 species, contain the most biodiversity in the world, according to a recently released marine census.
The oceans off China, the Mediterranean Sea and the Gulf of Mexico round out the top five areas most diverse in known species.
Census of Marine Life scientists released an inventory of species distribution and diversity in key global ocean areas, representing the most comprehensive and authoritative answer yet to one of humanity's most ancient questions: "what lives in the sea?"
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.
The relatively isolated regions Australia, New Zealand, Antarctica or South Africa have the most endemic species. They may have suffered fewer extinctions from climate cooling thousands of years ago during glaciation.
But much remains unknown. Says Dr. Ian Poiner, CEO of the Australian Institute for Marine Science and Chair of the Census Scientific Steering Committee: "Consider that a well-informed person walking along a familiar seashore might identify 20 species or so a fish monger perhaps 100. Even in the world's least diverse marine regions, there are 50 to 100 times as many named species than an expert would know without resorting to field guides."
The scientists' papers help set a baseline for measuring changes that humanity and nature will cause.
