A team of researchers will begin flights over Bering Sea ice to answer a basic question about four of the region’s most important species: How many ice-dependent seals are out there?
Scientists from the United States and Russia will count ringed and bearded seals, which the National Oceanic and Atmospheric Administration has recommended for listing as threatened species due to climate warming.
The agency is conducting a status review of a third ice-dependent species, the ribbon seal, and will also count spotted seals, a species it rejected for listing three years ago.
Getting an accurate count has been challenging due to the expense of conducting research in a remote location, the difficulty of counting species that spend time on both water and ice, and the danger to scientists flying in small airplanes.
Scientists hope to obtain significant results beginning this week by combining thermal imaging with high-resolution photography.
“The most novel thing about the survey is the pairing of two devices that have already been used to survey other marine mammals,” said Peter Boveng of the National Marine Mammal Laboratory in Seattle, in the announcement of the study.
The two aircraft picked for the project will fly at 1,000 feet, which is too high for the human eye to distinguish the seals. The thermal sensors, Boveng said, will locate the animals. The high-resolution cameras will take images to be analyzed in a lab.
“Thermal or infrared cameras are good at detecting seals on ice, which are very warm relative to their surroundings, but not good at revealing the species of seals,” Boveng said. “High-resolution digital photos are good for species identification, but very labor intensive for detecting and counting seals.”
He said putting the two technologies together creates a more efficient system in which the thermal camera finds the seals and the photo camera allows identification of species.
The survey will be conducted into May and plans call for flying nearly 19,000 nautical miles over U.S. waters and 11,000 nautical miles over Russian waters, making it the largest-ever seal survey in the Bering Sea.
The first flights will begin from Nome. Five- to seven-hour survey flights also will originate in Bethel and Dillingham in southwest Alaska and St. Paul Island, the largest of the Pribilof Islands in the Bering Sea.
The Center for Biological Diversity petitioned to list ringed and bearded seals in 2008 and eventually sued to force a decision.