The Secret Lives of Wild Animals — Text-only | Flash Special Report
They say if you really want to get to know a place, let the locals show you around. So, researchers at Antarctica’s McMurdo Sound are doing just that by equipping Weddell seals with underwater cameras and data recorders.
By using the seals as research partners, the scientists are learning not only about seals—as they dive some 2,000 feet below the icy waters in search of food—but also about the habits of two ecologically important fish species. The Antarctic silverfish and Antarctic toothfish play major roles in the food web but are hard to study because they live out of sight beneath the ice pack.
Most knowledge about these fish species comes from information gleaned from the trawl catches of commercial fishing boats and the stomach contents of predators. Now, using the ‘seal cam’—a video camera mounted on the seal’s head and attached to sensing devices—researchers get a firsthand look at the fish in their own habitats as seals search them out.
Even with little change in the amount of daylight—the sun is up 24 hours a day in the austral summer—seals found silverfish at average depths of 1,135 feet during the day and 827 feet at night. Toothfish, thought to be bottom-living fish, generally hung around at depths of 55 to 550 feet and also seemed to move deeper during the day.
Both fish and seal proved to be fast. During one particular two-and-a-half minute pursuit, the two animals reached speeds of 7 miles per hour.
Scientists say such sampling devices attached to predators could help study other marine mammals that are particularly hard to study in the open ocean.
1. Researchers are using Antarctica’s Weddell seals as research partners by equipping them with underwater cameras and data recorders. Credit: Commander John Bortniak, NOAA Corps
2. Scientists are learning more about the Weddell seals’ diving characteristics and feeding behaviors by temporarily attaching cameras and other data recording instruments to them. Credit: James Hebrlee, National Science Foundation
3. Weddell seals are generally calm, sedentary animals, but they are highly adapted to hunt for fish beneath the extensive ice of Antarctica’s McMurdo Sound.
Mike Cameron, National Marine Mammal Laboratory