Killer whale biologists used a hexacopter drone last month to capture stunning, overhead photos of every single member of the endangered Puget Sound orca population.
U.S. and Canadian scientists launched a small unmanned hexacopter — a six-rotor, battery-powered helicopter — from their research boat when they found pods of killer whales.
Vancouver Aquarium marine mammal scientist Lance Barrett-Lennard said the drone was designed to take really crisp pictures straight down from about 100 feet over the water.
“We watched carefully during the study for indications the whales were disturbed by the hexacopter — or even noticed it — and we found no indication of either,” he said.
Barrett-Lennard said researchers are using the overhead pictures to make precise measurements of how fat the endangered whales are. The resident killer whales swimming around Puget Sound and Vancouver Island rely heavily on chinook salmon. As seen from the drone, the 81 members of the Southern Resident population are in good shape this year. Three or more even appear to be pregnant.
NOAA Fisheries and the Vancouver Aquarium co-sponsored the unmanned helicopter surveillance effort. The SeaWorld & Busch Gardens Conservation Fund provided startup funding for what the scientists hope will be a long-term monitoring study.
The research team first tried out their hexacopter last summer to study the Northern Resident orca population at Johnstone Strait, along northern Vancouver Island. They returned there this summer before relocating to the waters around the San Juan Islands in September.
During a news briefing streamed online Wednesday from the Vancouver Aquarium, the scientists reported they collected about 40,000 images this season from the Johnstone Strait area and an equivalent number from San Juan Islands waters.
Barrett-Lennard said the images will provide “an excellent baseline of measurements to detect change in the future.” He said the objectives of on-going study are to measure growth rates, pregnancy rates and most important, changes in body condition in relation to changes in abundance of salmon.
“It’s only a few decades ago that to tell what condition a whale was in it had to be on the deck of a whaling ship. Now we can tell what condition a whale is in by taking a photograph of it,” said John Durban, a researcher and the drone pilot. Durban works out of the NOAA Southwest Fisheries Science Center in San Diego.
“It’s like having a new set of eyes,” Barrett-Lennard added with regard to the higher resolution the drone offers compared with previous attempts to shoot the same kind of photos from a manned helicopter hovering 750-1,000 feet overhead.
The research team said they did not have quite enough data to directly correlate the good condition of the orca whales this year with the favorable foraging conditions. Barrett-Lennard observed 2014 and 2015 were both “quite good years” for chinook salmon in the Pacific Northwest.
But he was quick to note this could change in light of current drought conditions, which are not promising for salmon spawning success.
“We’ve seen a couple of good years and we’re thinking that sadly, we could be looking at one of our bad years coming up soon,” Barrett-Lennard said.
NOAA said the small population of Southern Resident orcas is currently not meeting the recovery goals set under the Endangered Species Act, despite the birth of five calves this year.
“I think this is a great new tool that gives me some hope that we’ll be able to make some great management decisions, perhaps target some salmon recovery actions that will really help and support the whales,” said Lynne Barre, the branch chief in the Seattle office of NOAA Fisheries who oversees killer whale recovery.
The scientists obtained multiple permits from both the Canadian and American governments to fly over the endangered killer whales.
“The combined weight of our permits exceeds the weight of the hexacopter,” Barrett-Lennard joked. The purpose-built, flying camera weighs just over one kilogram.