This year has seen a record high number of gray whale strandings in Washington. Researchers are coming up with new methods aimed at figuring out why this is happening
Earhart didn’t come back to North Puget Sound this year. She is one of about a dozen “Sounder” gray whales that feed in the Sound between March and June as they migrate north from Mexico. When she first showed up in the group more than 30 years ago, she was already an adult.
John Calambokidis, a senior research biologist and founder of Cascadia Research Collective, estimates Earhart to be about 40 years old, a grand old dame by whale standards.
She has been back most years since 1990. But every three to six years, she would not return.
“We suspect some of the females don’t come back in the years when they might have a calf, making it too risky to navigate the convoluted route into Puget Sound,” Calambokidis said, “But given her age, she may also have died.”
Washington has had a record high of 30 gray whale strandings so far this year. Monitoring them has become ever more important in order to understand why they suffer such severe malnutrition that some cannot make it back to the Bering Sea to feed in the summer.
But monitoring gray whales is hard. Their markings are not as distinct as humpbacks or blue whales. While their pigment patterns stay the same, they are often covered with barnacles and scars.
“If you haven’t seen a whale for years, it can take hours to compare its image with the thousands of gray whales we have in our catalog,” Calambokidis said.
An automated matching technique using photogrammetry can now cut identification down to minutes. The algorithm uses artificial intelligence to compare the images of the dorsal ridge with what’s in a catalog of some 3,000 gray whales. Scientists can then better understand the behavior of individual whales.
Earhart, the researchers learned, is a leader among whales. They attached a tag to her back one year, hoping to learn where she was heading. But the tag was accidentally flipped backward by the pectoral fin of a passing whale. Then came the surprise video showing several whales following Earhart to the feeding ground in Puget Sound.
Whale watching on Google Earth
Once they are in the Sound, the whales head for the beaches. The area just south of Tulalip, for example, is a popular spot. At high tide, they roll laterally, usually on their right side, and their heads form pits in the sand. Their tongues loll in their open mouths such that the sediment rich in ghost shrimps flow through their baleens. The pits from this feeding action are visible on Google Earth as dark spots in the sand.
“A single whale can feed like this more than 300 times a day during a very short period of time when the tide is high,” said Hannah Clayton, a doctoral student at the Department of Oceans at Stanford University. “No other species of whale leaves these feeding pits on the intertidal.”
From the number and spread of the pits, researchers now know which beaches the whales favor and when they feed. Gray whales, as a baleen whale, are not known to have high social connectivity like tooth whales, such as orcas.
“What surprised us is how social the Sounder whales are, the way they come back consistently every year and how they learn from each other to feed this way,” Calambokidis said.
Clayton also studied the call of the Sounder whales. The data shows that they tend to call before and after a feed.
“We cannot make any assumptions about a wild animal, but I believe the calls signal a change in behavior and some form of socialization,” Clayton said.
Whale tagging
The trickiest part though is still deploying a tag on a whale in order to collect the data.
Both Calambokidis and Clayton have braved the waves in dinghies to get within yards of the whales. They would poke at the gentle giant with a long pole with a suction cup tag at the end, and with luck, it would stick.
“It’s exciting, intense and dangerous, and it’s my favorite part of my job,” Clayton said. She used to be a medic in the army and just loves the adrenaline flow.
In recent years, by using drones to deploy the tags, researchers have been able to reach whales much further out in the water.
“The drones are less disturbing for the whales, but the suction cups sometimes don’t attach well. They may stay on for only a few hours. This method also costs more. The drones can be more than $10,000 each,” Calambokidis said.
Lauren Wild, an assistant professor at the University of Alaska, studies whales at Sitka, Alaska.
“The federal government is starting to require that if you have federal funding for research, you cannot use Chinese made drone parts. They are worried that the Chinese government might use the data to spy on us,” Wild said. “But the 100% American made drones are $40,000 each.”
Aerial photos taken with drones tell researchers about the condition of a whale. Photos taken by Holly Fearnbach of the nonprofit SR3, show that some whales fatten up significantly after feeding only two months on the ghost shrimps in Puget Sound.
“They are getting three times their daily energy requirements from foraging on ghost shrimps in Puget Sound than they would in the Arctic,” Clayton said. She is now working on how sustainable Puget Sound is as a feeding ground as more and more whales choose to come here. So far the shrimps are in abundance. But warmer water has already impacted the crab population in the Pacific Northwest and in the Arctic and it is unclear if the shrimps will be impacted as well.
Scientists are trying to expand on the types of data they can collect using tags, such as measuring whales’ heart rates and the stress hormones in their blow.
The Puget Sound success story
There is still a lot to be learned about how gray whales navigate the oceans. No one knows for sure how the first Sounder whale, aptly named Shackleton, located Puget Sound at least 36 years ago. But this year, the first Sounder whale appeared in December, months before the usual northward migration between March and June. They are also staying longer in Puget Sound.
While the strandings are disturbing, Calambokidis believe the Sounders are actually a success story in how the whales can find new foraging areas and adapt to a different diet.
“Some of these whales are not going south to their breeding ground in Mexico in the winter and that may eventually affect the overall size of the population,” Calambokidis said.
“It took me a while to realize that the years of high strandings are also the years of high mortality in the overall population,” he said. Most of the whales that wash up are severely malnourished whales. Calambokidis said they did not feed well in the Arctic the previous year. When they try to migrate up north again in the spring, they are at their weakest and some simply do not have the energy to make it to the Arctic.
In Sitka, about 20 whales have opted to gorge on herring eggs instead of going further north. Wild pointed out though that the Tlingit tribes in the area have harvested herring eggs from kelp which they place in the water. So the increase in this group of whales is of interest to those trying to preserve a tradition.
The adaptation to a new diet has been less successful in some places. The gray whales leap out of the water to feed on anchovies in San Francisco Bay, but the marine traffic there makes this a dangerous feeding ground. The Center for Biological Diversity is suing the U.S. Coast Guard to ensure shipping lanes are designed with the safety of whales and turtles in mind.
Clayton pointed out that current coast guard regulations are such that pleasure craft and fishing vessels under 65 feet are not required to have an automatic identification system.
“That means when they strike a whale, the vessel cannot be identified nor do we know what speed it was travelling at,” she said.
What can be done
The researchers say citizen scientists can help out by sending photos of whales to Cascadia Research Collective. Pictures of the dorsal ridge or the head are ideal for identification. Photogrammetry sites such as Happywhale.com or Flukebook.org also collect images, though Happywhale does not include gray whales yet.
“There is only so much that researchers can do, and we can use all the help we can get,” Wild said.
—By Jenny Lam