Scientists Take to Skies to Count Threatened Seals

An adult male ribbon seal stands out against floating ice in the Bering Sea. CREDIT: NOAA. View full size image

A few days from now, weather permitting, the most ambitious survey of Arctic seals ever attempted will send scientists soaring above ice-choked seas to count mammals that many fear are facing increasing threats because of climate change.

A joint team of U.S. and Russian scientists is slated to spend mid-April through May flying nearly 35,000 miles (56,000 kilometers) over Arctic waters that border the two countries aboard small aircraft.

The planes are scheduled to fly at altitudes between 800 and 1,000 feet (240 and 300 meters) to avoid disturbing the animals, and researchers will use high-resolution digital cameras and thermal sensors to spot the seals. The images will be analyzed later in the lab.

"The most novel thing about the survey is the pairing of the two imaging devices," Peter Boveng, a biologist with the National Oceanic and Atmospheric Administration and one of the principal investigators of the survey, said in a statement. "The thermal or infrared cameras are good at detecting the warm seals on ice, but not for identifying the species of the seals. The high-resolution digital camera provides photos that can be used for species identification, and counting seals. By putting the two together, an efficient system is created," he said.

Spring is an ideal time to study the four species of ice-associated seals that live in the Bering Sea— the main target of the survey — which is typically a difficult place for scientists to work. It's remote, and the weather is cold and unpredictable. But during the spring months, the marine mammals spend their time hauled out on floating sea ice to breed, pup and molt, which makes it far easier to count them.

Four species of ice-associated seals are found in the Bering Sea: spotted seals, bearded seals, ringed seals and ribbon seals — a species that recently showed up in a very strange place.

As the extent of sea ice on Arctic waters has increasingly dropped over the years, concern for the seals' future has grown. The animals depend on sea ice for survival, and all four species are being reviewed under the Endangered Species Act.

Data from the upcoming aerial survey will be used to help define the seals' status and level of protection.

In addition to facing long-term threats from climate change, it was recently discovered that some Arctic seals and walruses are suffering from a mysterious malady that causes skin lesions, open sores and fur loss. Testing has ruled out quite a few diseases, but researchers haven't yet pinpointed what is killing off the animals; the research is ongoing, according to federal authorities.

This story was provided by OurAmazingPlanet, a sister site to LiveScience.