Drone allows scientists to take detailed images of resident orcas

A camera mounted on a drone is allowing scientists to get close enough to take stunning, detailed images of resident killer whales to track their health.

Called photogrammetry, the method is used by research biologists John Durban and Holly Fearnbach, both with the National Oceanic and Atmospheric Administration. The photos enable them to measure a whale’s length, in order to monitor growth, and their width, to see whether they’re pregnant and how fat they are.

“We’re really answering a very simple question: Are these killer whales getting enough to eat?” Durban said Wednesday, Oct. 21, as part of a panel of scientists discussing the second year of research, which expanded this summer to include the endangered southern resident killer whales in area waters.

The first year focused solely on the northern resident killer whales, off the coast of Vancouver Island.

The southern residents spend part of the year around the San Juan Islands north of Seattle. They now total 81 and their low numbers make the southern residents among the eight species under NOAA’s watch that are most at risk of becoming extinct.

Both populations eat Chinook, and several stocks of these salmon are themselves dwindling.

The research is a collaboration between NOAA Fisheries and the Vancouver Aquarium.

“One of the best indicators of the health of an ecosystem generally is the presence and abundance of large predators,” said Lance Barrett-Lennard, Vancouver Aquarium’s senior marine mammal scientist.

“As impressive as they are,” Barrett-Lennard added of the iconic whales, “their existence depends on intact marine food chains from plankton on up.”

Initial results from this year’s monitoring indicated the southern residents were faring well, given the five calves born in the past 12 months that seemed to be in good condition and an abundance of Chinook for both northern and southern residents.

“We just hope they keep this baby boom going,” said Lynn Barre, branch chief for protected resources with NOAA Fisheries.

The work that’s been done so far will hopefully allow scientists to create a baseline for comparisons year to year and to manage their recovery, officials said. They also want to use the photos to link the whales’ health to salmon runs and abundance.

Scientists aren’t drawing any conclusions yet, though.

“I think it’s a bit too early to make conclusions,” Durban said, “ just because we’ve only got a couple of years for comparison.”

The scientists said, for example, that this cycle may have been a good one in terms of the abundance of Chinook but they were worried that warm temperatures and low river flows are bad news for spawning salmon and, therefore, the whales’ food supply.

“We’re thinking that, sadly, we could be looking at one of our bad years coming up,” Barrett-Lennard said.

The camera was mounted on a specially made drone called a hexacopter, which weighed a little over 2 pounds and had six motors and six propellers to provide stability. It was operated remotely by Durban. Because it was quiet, the researchers were able to get the drone within 100 feet of the whales without disturbing them, they said.

That allowed for up-close photos that weren’t possible before from manned helicopters, which are usually 750 to 1,000 feet above the whales.

“It gives us a view we haven’t seen before,” Durban said. “We can look at scars and scratches on the whales.”

The photos, 40,000 for each resident population this year, also provided intimate glimpses of their behavior and family bonds.

One image showed a baby whale, L122, just days after he was born to first-time mother L91 as they swim side by side.

“This is the smallest calf we’ve ever photographed from the air,” Durban said. “What I love about the picture is the kind of nurturing you see here.”

Another photo showed other family members bringing salmon to a mother so she can conserve her energy while nursing.

“It’s a great example of how society and group living is really important to these whales,” Durban said. “They do family better than we do.”

A stunning image of a 20-year-old whale, named L94, nursing her calf also was captured by the camera mounted on the hexacopter.

“It’s certainly the first time we’ve seen it with this clarity,” Durban said of the nursing photo.

Researchers said they were able to fly over the southern resident whales after getting a permit from National Marine Fisheries Service and flight authorization from the Federal Aviation Administration.

This story was originally published October 21, 2015 at 11:51 AM with the headline "Drone allows scientists to take detailed images of resident orcas."