When a researcher first went to study whales from the air, he worried for their future. His recent findings make him hopeful.

In 2018, the federal government convened an urgent meeting in Hawaii to gather researchers from across the Pacific to figure out what to do about a grim trend: a sudden drop in the presence of humpbacks around the Hawaiian Islands.  

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The situation began unfolding a few years earlier, when a devastating heat wave struck the North Pacific near Canada and Alaska. Fish stocks collapsed. Seabirds starved to death. Humpback whales became emaciated, and thousands of miles away in Hawaii, researchers saw far fewer whales traveling to the islands each winter to breed.

“I remember sitting there thinking, it’s almost like finding out that a friend of yours is dying,” said Joe Mobley, a professor at the University of Hawaii Manoa. “Are we going to lose the whales in my lifetime?”

An estimated 10,000 to 12,000 humpbacks travel to Hawaii waters to breed, give birth and nurse their young each year. (Marina Riker/Civil Beat/2023/NOAA Permit No. 19655)

Mobley was among the whale experts who came together and settled on a mission to better understand why so many whales had vanished from Hawaii waters. He was braced for dire results, but in the years that followed, he found the opposite.

In a new study released earlier this year, Mobley and other researchers determined the presence of humpbacks around Maui Nui in 2019 and 2020 was similar to 20 years ago. And if anything, there were even more calves than in the past.

In the aftermath of the 2018 meeting, scientists took to the skies to document whales in the waters around Maui, Molokai, Lanai and Kahoolawe by plane. From Mobley’s perspective, the fact that the whales recovered there so quickly from such a major climate disaster shows that humpbacks are “remarkably resilient.”

It’s giving scientists hope for the whales’ future as the climate crisis melts glaciers and sea ice, warms ocean temperatures and disrupts global food chains.

“That’s the question now,” Mobley said. “Is their resilience so good that they can handle even the pace of change that’s happening now? We don’t know. But this is hopeful.”

The study published in the scientific journal Marine Mammal Science was conducted in partnership with several other leading scientists, including Mark Deakos of the Hawaii Association for Marine Education and Research, Adam Pack of The Dolphin Institute and University of Hawaii at Hilo, and Guilherme Bortolotto of the Scottish Oceans Institute at the University of St. Andrews.

Maui Nui is a favorite spot for humpbacks returning to Hawaii each year. (Marina Riker/Civil Beat/2023/NOAA Permit No. 19655)

The study built on decades of work stretching back to the 1980s, when Mobley first began research under the mentorship of Louis Herman, a trailblazing marine scientist who pioneered the study of humpback whales in Hawaii. Herman began the first aerial surveys in the 1970s that were used to gauge the density of humpbacks in Hawaiian waters — the measurement that estimates how many whales there are per square kilometer.

In the 1970s, the first studies estimated that there were anywhere from about 250 to 600 humpback whales in the Hawaiian Islands — the population was still reeling from generations of whaling.

Mobley continued the studies by plane through the 1990s and early 2000s, documenting the changes as their population kept growing by an estimated 7% per year. They were making a massive comeback. By the early 2000s, researchers estimated that 10,000 humpback whales migrated to the islands each year.

But after the early 2000s, funding for Mobley’s aerial surveys dried up. It wasn’t until 2019 that he and other researchers were able to find the cash to get back up in the sky to understand how the whales were coping in the changing sea. He’s hoping to obtain additional funding to continue the studies, which would help scientists confirm if the number of whales in Hawaii might be increasing or just staying level.

Besides helping to fight climate change, humpback whales also help to bolster Maui’s economy. (Marina Riker/Civil Beat/2023)

He’s also hoping it might shed light on another surprising development in the humpback whale research realm — a sudden uptick in sightings of humpback whales feeding in Hawaii. For decades, the conventional wisdom has been that whales don’t eat in Hawaii, and some people even went as far as suggesting humpbacks fasted while in the islands because they returned to the northern waters after having lost thousands of pounds of body weight.

Now, researchers like Mobley want to figure out whether whales might be eating more in Hawaii because their food elsewhere is threatened. But the way Mobley sees it, it’s also a reason for optimism because it shows whales can change their behavior on a dime to adapt to a rapidly evolving environment. 

“It’s a fascinating story because it’s like watching the same critters in your backyard for 40 years and suddenly they start doing different things you’ve never seen before,” Mobley said.

Researchers have a far better chance of spotting whales that might be feeding on schools of bait fish at the surface of the water from up in the air than they do by boat. Besides identifying what they’re snacking on, researchers also want answers to another unsolved mystery: whether the humpbacks have rebounded all across the Hawaiian Islands, or if they’re just concentrated around Maui Nui.

Decades ago, Mobley flew back and forth across the entire island chain, but the most recent efforts focused solely on the area around Maui because of funding limitations. One of his co-authors on the study, leading whale researcher Adam Pack, said similar research efforts will be vital in the future to understand whether heatwaves and other climate events are threatening Hawaii’s humpbacks and the ocean as a whole.

Pack explained that humpback whales are important to conserve in part because of the role they play “in protecting us from out of control climate change.”

Humpbacks keep the ocean and the planet healthy. They trap carbon in their enormous bodies, taking it out of the atmosphere for centuries. Fish feed off their dead skin, and their poop serves as a fertilizer by providing nutrition for phytoplankton, the tiny organisms that suck carbon dioxide out of the air.

But for Pack and researchers like Mobley, who’ve been studying Hawaii’s humpback whales since their 20s, protecting the marine giants is more personal.

“We’ve been tracking individuals for 30 and 40 years now,” Pack said. “When you get to know them on an individual basis, of course you feel this aloha for them.”

Civil Beat’s coverage of Maui County is supported in part by a grant from the Nuestro Futuro Foundation.

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