The findings contradict a general consensus that humpbacks usually just breed in Hawaiian waters then return to feed around Alaska and scientists want to know why.

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Nick Moran set out in his helicopter on a recent morning to find whales.

Maui County

The pilot and owner of Go Fly Maui was taking a couple visiting from the mainland on a tour to photograph humpbacks from the air. They were off the coast of Molokai, after sightseeing around the island’s famous cliffs, when they saw a massive school of small fish. 

As they flew closer, a humpback whale lunged up from below, engulfing its prey. They watched as it launched up to take a gulp a half dozen times. After a few minutes, a larger whale joined in to feed.

“I’ve never seen this in Hawaii ever,” Moran said. “It was a bit of a National Geographic moment.”

Moran is a fisherman and had heard stories over the years that whales often hung around popular bait fishing spots. But he also knew that what he was seeing was extraordinarily rare.

For decades, the conventional wisdom has been that whales don’t eat in Hawaii. It was a mantra repeated by tour operators and whale watch leaders. Some people even went as far as proposing that humpbacks fasted while in the islands, where they migrate each year to breed, give birth and nurse their young. 

Instead, their rich feeding grounds are in the colder waters near Alaska, home to large populations of krill and small sea creatures that are higher in fat and calories. But earlier this year, after Moran posted the photos of the feeding his tour group captured on Facebook, he was contacted by a researcher from the National Oceanic and Atmospheric Administration. 

Less than two weeks before, the federal government’s scientists had witnessed something similar off Maui. The events have raised all sorts of questions about humpback whales, how they use Hawaiian waters and what that might say about the ramifications of climate change, warmer ocean temperatures and the dynamic marine food chain. 

“I knew that if they could find food, they would eat it,” Moran said. “These guys are survival experts.”

Despite decades of research on humpback whales, their diets in Hawaii are still perplexing to scientists.

Marc Lammers, a biologist and the research coordinator for the Hawaiian Islands Humpback Whale National Marine Sanctuary, was on a research trip to tag whales in late January when his crew spotted what they first thought were a couple of younger whales behaving in a strange way near the surface of the water out of West Maui. Initially, it didn’t strike Lammers as something too peculiar because younger whales often play and behave in unusual ways.

But as their boat inched closer, Lammers realized it was just one whale — lunging toward the surface with its mouth wide open, ready to take a big gulp.

That’s when he noticed the massive bait ball in the water.

“This whale was very clearly feeding,” Lammers said.

They took videos, photographs and made an unsuccessful attempt to tag the whale. But after 15 minutes or so of feeding, the whale moved on.

Because whales’ enormous bodies store so much carbon, they can help combat climate change. (Marina Riker/Civil Beat/2023/NOAA Permit No. 19655)

After it was over, Lammers thought that he’d witnessed a “once-in-a-lifetime” event — until less than two weeks later, he came across the helicopter tour’s photographs on social media. Now, he’s trying to figure out what the sudden uptick in feeding sightings means for humpback whales and their role in the complex marine ecosystem.

“It’s obviously not as black and white as we thought,” Lammers said.

In his work for the sanctuary, Lammers is focused on protecting the humpbacks and their habitat in the 1,370-square-mile area. The sanctuary is home to one of the most important humpback whale habitats in the world. 

Humpbacks play a key role in keeping the ocean healthy. They act as fertilizers for the ocean; their poop, for instance, provides a pivotal supply of iron for marine life and is a key source of nutrition for phytoplankton, the tiny organisms that supply a huge portion of the oxygen in the air we breathe.

To protect the whales and the ocean as a whole, Lammers wants to better understand what they need to thrive in Hawaii. He wasn’t able to identify what they were feeding on that day, but he was later told by a fisheries expert that there have been lots of reports of bait fish like nehu in Hawaii waters this year. Getting an exact answer to that question could help researchers shed light on when — and where — humpbacks might snack in Hawaii.

Federal law prohibits approaching whales within 100 yards. NOAA scientists are granted a special exemption for research. (Marina Riker/Civil Beat/2023/NOAA Permit No. 19655)

For the most part, researchers have studied humpback whales and how they’re using their environment during daylight hours; what happens after dark is still unknown. But it’s after the sun goes down that the calm waters seen during the day transform, when fish and other types of prey rise up from the depths of the ocean and become the target of dolphins, tuna, mahi mahi and other predators.

“This has the whole local humpback whale research community scratching their heads,” said Lammers. “What’s really going on?”

Lammer’s colleague, Ed Lyman, a natural resource specialist for sanctuary, said he heard similar stories from fishermen about an uptick in whales feeding in 2011. Much like this year, fishermen and researchers had noticed an especially high number of bait balls in Hawaii waters. 

“We’re noticing a lot of food out there this year,” Lyman said. “It’s like if you have lots of donuts laying around, people are going to eat.” 

About 10,000 to 12,000 humpbacks migrate to Hawaiian waters each year. (Marina Riker/Civil Beat/2023/NOAA Permit No. 19655)

This whale season, Lyman said, he’s seen more bait balls than in the last 20 combined. Tour operators, meanwhile, have been noticing the consequences of that: more whale poop. So Lyman and other researchers have collected some, in hopes that eventually a laboratory analysis could help shed light on the situation. He thinks the whales are essentially snacking; it’s not like the full meal they get in the feeding grounds near Alaska, but it is something.

But the sudden increase in feeding sightings does raise a lot of questions. Are the recent incidents an anomaly, or just the tip of the iceberg? Are humpbacks eating more in Hawaii out of necessity? Could the sudden surge in bait fish have to do with climate change, or the increase of runoff into the sea after winter storms?

In recent years, disruptions to whales’ habitats have been top of mind for scientists. Around 2016, a marine heatwave struck the northeast Pacific in the whales’ feeding grounds near Canada, disrupting the ocean’s regular balance and collapsing key feeding grounds. In the years that followed, scientists estimate the number of whales that returned to Hawaii to breed was cut in half, although that number has risen again since.

“It’s never one thing,” Lyman said. “Ecology is so much more complex.”

Civil Beat’s coverage of Maui County is supported in part by grants from the Nuestro Futuro Foundation and the Fred Baldwin Memorial Foundation.

Civil Beat’s coverage of climate change is supported by the Environmental Funders Group of the Hawaii Community Foundation, Marisla Fund of the Hawaii Community Foundation and the Frost Family Foundation. 

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