SANTA CRUZ, Calif., Oct. 7 (UPI) -- Seals diving deep in the ocean for food near Antarctica are helping provide extremely accurate data for use in mapping the sea floor, oceanographers say.
Seals, walruses, whales and other large marine creatures have helped oceanographers before, as scientists have glued sensors to the animals' bodies that measures factors like temperature and salinity, ScienceNews.org reported.
The new work with elephant seals is the first to extract information on the shape of the seafloor -- known as bathymetry -- from new sensors, glued to the animals' heads, which can measure pressure and hence depth.
"You can actually map the ocean floor," Daniel Costa, a marine biologist at the University of California, Santa Cruz, says.
The data came from 57 elephant seals tagged by Costa's group during five summers at the U.S. Antarctic Marine Living Resources camp in the South Shetland Islands. As the animals swim, the tags record information every few seconds, then relay it via satellite once the seals surface.
About 30 percent of the time seals dive all the way to the bottom to forage for food, so by studying enough dives for each animal -- about 200,000 dives in all -- researchers can create a map of the sea floor.
And the seals do it all for a fraction of the cost of traditional seafloor mapping done from ships, scientists say.
"It gives you a much denser picture of what the water depth is than anything you can conceivably do with ship tracks," says oceanographer Laurence Padman, a coauthor of an upcoming paper in Geophysical Research Letters describing the technique.