Can drones help save the whales?

In August, scientists from the National Oceanic and Atmospheric Administration and the Vancouver Aquarium conducted a series of drone flights over British Columbia’s Johnstone Strait to monitor the health and reproduction of threatened Northern Resident killer whales from 100 feet in the air.

It was the first time researchers had deployed an unmanned aerial vehicle, in this case a six-bladed, remote-controlled helicopter called a hexacopter, to observe orcas.

Scientists are trying to determine if the salmon-eating killer whales are getting enough food by analyzing the high-resolution photos to observe the weight of individual animals. They can also see which females are pregnant and confirm the percentage of successful pregnancies.

(Photo: Courtesy NOAA)

“We collected just under 20,000 images during 60 flights of 77 Northern Resident killer whales and five transient (mammal eating) killer whales,” John Durban, a population ecologist for NOAA Fisheries, said in an email.

Scientists previously used helicopters to observe the Northern Residents and their endangered counterparts, Southern Resident killer whales. But research helicopters are expensive to operate. And because they’re noisy, they must maintain an altitude of 750 feet or greater to avoid disturbing the marine mammals. A quiet, battery-powered drone, on the other hand, can hover as low as 100 feet without the whales even noticing.

“We need overhead images linked to precise altitude in order to estimate size, and we use aerial images of shape to assess body condition,” Durban said. “The hexacopter is small and portable, so it can be used in relatively remote situations.”

(Photo: Courtesy NOAA)

NOAA is deploying similar technology for measuring and counting penguins and seals in Antarctica and Steller sea lions in Alaska.

“We hope these metrics will provide sensitive indicators of condition and nutritional status to guide conservation management,” Durban said. “Conservation plans in the U.S. and Canada cite prey availability as a key factor in viability and recovery of these two populations, so it is important to monitor nutritional status.”

Both whale populations rely heavily on salmon—especially fatty and calorie-rich chinook—for their survival. But overfishing, pollution, and dams have vastly reduced fish stocks in recent decades. Some salmon populations are themselves endangered.

(Photo: Courtesy NOAA)

Southern Resident whales have suffered more severe declines than their northern counterparts. In the 1960s and ’70s, one-third of the wild population was captured or killed so the whales could be displayed at marine parks, according to the Center for Whale Research, a nonprofit based in Friday Harbor, Wash. The Southern Resident population numbers about 80.

“We are keen to assess their comparative nutritional status and see if food is limiting,” Durban said. “Northern Residents are the nearest neighboring population to Southern Residents, so they offer the best comparison.”

More flights are planned, and not just for orcas. “Now we have a reliable, cost-effective, and noninvasive platform, I think there are many potential applications to fill key data gaps,” Durban said.

He stressed that the research team obtained all the necessary permits to conduct the aerial surveillance, and NOAA Fisheries has a message for amateur drone enthusiasts: Don’t try this at home.

“Whales are very sensitive to what goes on around them,” says NOAA’s website, which cautions that non-research drone regulations require an altitude of 1,000 to1,500 feet, depending on the species.

“If you’re a hobbyist with a hexacopter,” the agency warns, “please respect the regulations, and marine mammals, by giving them the required space.”