Here's a challenge for a marine ecologist: Find out what it's really like to survive as a seal or a fish in the dark, cold, forbidding waters beneath Antarctica's floating ice fields.
It would be helpful to find a camera crew willing to strap on a bunch of equipment and dive hundreds of feet below the ice while snapping pictures of seals zipping through the water toward their prey. The crew would also need to keep a record of all sorts of things like water temperature, depth and location.
And, of course, they would need to survive the ordeal and return the equipment and all the data recorders to the scientist. That's an assignment that's not likely to appeal to very many photographers, so Lee Fuiman of the University of Texas and a few colleagues came up with an alternative. They recruited a bunch of Weddell seals to serve as their film crew.
The result, Fuiman says, is an extraordinary look at survival in the trenches beneath the ice that blankets Antarctica's McMurdo Sound for most of the year.
Star Cameraseal Ally McSeal
Fuiman, Randy Davis of Texas A&M, Galveston, and Terrie Williams of the University of California, Santa Cruz, have completed the first three-year phase of the project, sponsored by the National Science Foundation, and they have moved on to a more complex phase.
They couldn't have done it without the help of seals like the one with so much personality she was dubbed Ally McSeal, who became so fond of her collaborators that she returned to their base camp several times, apparently just to say howdy.
The equipment was attached to rubbery material like that used for wetsuits, and the rubber was glued to the pelt of the seals. But since the equipment, consisting of sensitive video cameras and all sorts of instruments, was worth thousands of dollars, and since all of the data and images would be stored on board the animal, the researchers were kind of anxious to come up with a way to guarantee that they would be able to recover it all.
The scientists knew they wouldn't have any trouble catching a seal, because seals have no natural predators during the Antarctic spring, when the seas are covered by ice that keeps killer whales away.
"Getting close to them is quite easy," Fuiman says. "You can walk right up to them."
Right, but how do you make sure they'll come back at the end of the experiment so you can collect your instruments and data? You make sure they don't have any choice.
One Exit Only
In the first phase of the project, the scientists searched the ice field for areas that had no holes or cracks where seals could surface and breathe. Then they drilled a hole in the ice and set up their laboratory over the hole.
"Then we would go out and catch a seal, bring it to our laboratory, put the equipment on it and release the seal into the hole," Fuiman says. That left the seal free to resume its normal activities, including searching for food. But in order to breathe after diving for anywhere from 20 to 70 minutes, the seal needed to surface. And there wasn't any place to surface other than the hole beneath the scientists' lab.
In all, 15 seals took part in the experiment, diving to depths of more than 1,000 feet, where water pressure was so great it squeezed their lungs down to a fraction of their normal size. But in the end, all the seals had to return to the lab if they wanted to take that essential breath of fresh air.