South of Easter Island, Census vent explorers discovered a crab so unusual it warranted a whole new family designation, Kiwidae.
Marine scientists and explorers from more than 80 countries have finished an ambitious 10-year project to map the life in the world's oceans.
It is the first baseline documentation on the abundance and distribution of thousands of marine species that will help scientists track damage caused by oil spills, pollution and climate change.
The researchers mapped the migratory routes and hang-outs of scores of animals, from sperm whales to sooty shearwaters, seabirds that average 350 kilometres a day in their search for food.
"The tracking measured animals' surroundings as they swam and dove, and revealed where they succeed and where they die," says a document describing the highlights of the census findings made public on Monday in London.
In total, there were 540 research expeditions, involving icebreakers, divers, nets, submersible vehicles, acoustic tagging, listening posts and satellites. Scientists attached tags that measured water temperature, light, depth and salinity to 23,000 animals from 41 different species.
They explored the dark waters of both poles discovering strange, unknown creatures that live beneath the ice, including a pink octopus in the western Arctic Ocean.
In total, at least 6,000 previously unknown species were discovered as scientists explored deep sea vents, underwater mountains and coral reefs.
They found a Jurassic shrimp thought to be extinct for 50 million years, a "Yeti" crab covered in hair-like filaments, tube worms that were 600 years old, giant spiny lobsters half a metre long and sea spiders as big as dinner plates.
The census involved 2,700 scientists, and a number of Canadians played key roles, including Memorial University's Paul Snelgrove, who synthesized the decade worth of discoveries in a 304 page account, one of three official books about the census being launched on Monday.
The scientists found that, by weight, 90 per cent of marine life is microbial.
"The weight of the Earth's marine microbes equalled about 35 elephants for every living person," says a summary of census findings.
One of the most important legacies of the $650-million initiative is a network of microphones on the seabed to track salmon carrying miniature sonic tags and other migrants from California past Canada to Alaska. It tracked two juvenile Chinook salmon on a 2,500 kilometre journey that lasted more than three months and allowed scientists to learn more about the life cycles and movements of various species.
"The census united scientists from more than 80 nations with different talents, equipment and interests," said Dr. Snelgrove. "It matched the immensity and complexity of ocean life with a human enterprise able to grasp it."
But much remains unknown.
"After all its work, the census still could not reliably estimate the total number of species, the kinds of life, known and unknown, in the ocean," says the summary document.
"For more than 20 per cent of the ocean's volume, the census database still has no records at all, and for vast areas, very few."