Though scientists think that singing plays a role in breeding displays, a lot remains unknown about humpback songs.
Antoine Maillard(Photo)
Though scientists think that singing plays a role in breeding displays, a lot remains unknown about humpback songs.
Though scientists think that singing plays a role in breeding displays, a lot remains unknown about humpback songs. (Photo: Antoine Maillard)

The Man Who Wants the World to Hear Whale Songs

For more than three decades, Paul Knapp Jr. has taken travelers out into the Caribbean Sea to hear humpback whales. Now seismic blasts threaten to silence their songs.

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A thunderhead loomed to the south of the island of Culebra, in Puerto Rico, threatening to drench Paul Knapp Jr. and the three passengers of his 18-foot inflatable dinghy, the Little Compass. The sticker at the helm of his boat read: “I Speak Whale.” A sun-swept couple from Michigan waited toward the bow, while I sat beneath the Bimini top. As we exited the harbor, Knapp punched the engine and headed northwest, the wind to our stern. The Little Compass skimmed across the blue swells like a well-skipped stone.

After 20 minutes, we reached Knapp’s most reliable listening location, an indistinctive stretch of open water just west of a peninsula. Knapp cut the engine, plugged a hydrophone into a pair of boat speakers, and dropped the device into the water. “OK,” he said as the cable ran through his fingers, falling to 50 feet below the surface. “Let’s see if we hear anything.”

Within seconds, a chorus of cetacean song filled the air—humpbacks emanating a series of elevated chirps and bellows and downward-spiraling moans. I’d listened to countless whale recordings in preparation for the trip, but they failed to convey how haunting the songs are in person. Knapp fell silent for a few minutes before rattling off guesses at the whales’ numbers and distance from us—two or three of them, maybe three or four miles away.

For more than 30 years, Knapp has guided some 4,000 people on such listening trips in the Caribbean Sea, where many Atlantic humpbacks spend winter and spring, the males crooning in competition and the mothers nursing calves, before migrating north in search of fish and krill. Whale-watching attracts millions of visitors to hot spots like Hawaii, Alaska, and Puerto Rico annually. On Puerto Rico’s main island, tourists flock to the west-coast town of Rincón each spring for the annual Festival de la Ballena (Whale Festival), embarking on day trips with one of the numerous outfitters that line the streets. Despite the guaranteed business, Knapp prefers the aural experience. 

“As far as I know, I’m the only person who’s just listening,” he said. “I’m not interested in seeing them at all.”

Few people were listening to whales until 50 years ago, when biologists Katy and Roger Payne released the album Songs of the Humpback Whale, which featured little more than the calls against a backdrop of waves. It became an unexpected hit, selling more than 100,000 copies. In the years that followed, the album was part of a rise in international activism to protect marine mammals like whales, dolphins, and porpoises, inspiring people like Knapp to explore their vibrant vocal world. When the album was added to the National Recording Registry in 2010, it was called “probably the most famous nature album in American history.”

Within seconds, a chorus of cetacean song filled the air—humpbacks emanating a series of elevated chirps and bellows and downward-spiraling moans.

But with the discovery of whale songs and the critical nature of their submarine communications came revelations about an urgent threat from noise pollution. As anthropogenic activity floods the ocean with mechanical sounds, whales have been forced to compete with human-made noise in order to communicate.

Some 50,000 merchant ships traverse the ocean, their engines and propellers generating a din that can be heard from hundreds of miles away. And that’s nothing compared with the intensity of the sound created by seismic air guns used by many oil and gas companies at offshore sites across the globe. These blasts take place every ten to twelve seconds, can travel up to 2,500 miles, and can be as loud as 260 decibels—louder than a rocket launch. Whales migrating along the Atlantic coast of the United States have been spared from this disturbance since the 1980s, the last time seismic surveys occurred in this area. But in 2017, the Trump administration sought to lift Obama-era bans and open up the Atlantic, a move that’s been in limbo ever since.

Though scientists think that singing plays a role in breeding displays, a lot remains unknown about humpback songs. Experts aren’t sure how the male’s ballad functions—it might be meant to show off for females or to communicate with other males during mating season. (While female humpbacks also use sound for communication, they haven’t been observed singing like the males.) What we do know is that underwater noise pollution has been shown to increase stress hormones and disrupt migration patterns among many marine animals, including Atlantic humpbacks. Additionally, it’s been found that zooplankton—including krill, a main food source for whales—are especially susceptible to loud blasts. An impact study published in 2014 by the Bureau of Ocean Energy Management found that hundreds of humpbacks could be negatively affected each year if seismic surveys were permitted in South and mid-Atlantic waters. 

It disturbs terrestrial creatures attempting to listen in, too—since Knapp started his work, he has sometimes strained to hear and record whale songs amid the increased racket of boat traffic. As we drifted off the coast of the island, it wasn’t long before the whir of a yacht engine drowned out the sound of the calls.

Knapp reached over to turn off the speaker. “Let’s wait until this one passes,” he said.

Paul Knapp Jr. manning his hydrophone
Paul Knapp Jr. manning his hydrophone (Dyllan Furness)

On a spring morning in the late 1960s, Katy and Roger Payne stood on the deck of a Navy vessel circumnavigating Bermuda, their eyes fixed on the horizon in search of whale spouts. The Paynes were guests of Frank Watlington, a Navy engineer who spent years monitoring underwater acoustics as a way to eavesdrop on enemy submarines. Their eyes strained—not a whale in sight. At the time, commercial whaling was in full swing, so the absence of whales seemed like a sign of the creatures’ demise. But Watlington knew whales were out there. He’d heard them. Before heading back to shore, he invited the Paynes into the ship’s engine room, where he played the them a ten-minute recording. It was so poignant, Katy later recalled, that they wept.

In the decade prior, Watlington had used a hydrophone to record these mysterious sounds, which he thought, based upon his years at sea, came from humpbacks. According to Katy, he’d kept the tapes a secret, worried that whalers would exploit the sounds to call the creatures close during hunts. As the Paynes told NPR, Watlington entrusted them with reels of his recordings and issued a directive: “Go save the whales.”

“We came home with our heads absolutely delirious with excitement,” says Katy, who later became a researcher of bioacoustics at Cornell University. “It was overwhelming to suddenly know that these huge, mysterious animals had a way of communicating that had reached us.”

Over the next few years, the Paynes immersed themselves in the alien world of Watlington’s recordings. With Roger’s experience studying echolocation and Katy’s training in music and biology, the pair were well equipped for the challenge. They soon made field recordings of their own, embarking on expeditions from Bermuda to Hawaii. Through hours of close listening and analyses of spectrograms to help them visualize the sounds, Roger and his colleague Scott McVay discovered that the whale calls contained distinct structures and repeating themes—meaning that humpbacks don’t just chat to each other, they sing. What’s more, males within local groups perform roughly the same tune. Katy would later discover that songs evolved from one breeding season to the next, as individuals adopted creative flourishes from one another.

For Katy, the discoveries showed that whales were more than lumbering leviathans screaming into the ocean abyss. Instead she interpreted their songs as evidence of a social system once thought exclusive to humans. “There’s a culture here,” she said. “It’s the evolution of a culture that we’re looking at.”

The Paynes released the five-track Songs of the Humpback Whale in 1970, featuring three of Watlington’s recordings and two of their own. It was a popular time for marine mammals: hit shows like Flipper and attractions like SeaWorld had recently been introduced. That same year, the federal government listed humpbacks as an endangered species, after centuries of rampant whaling had left them on the brink of extinction, with just 10,000 to 15,000 counted across the planet at one point. One of the songs off the album earned a spot on NASA’s Golden Record, which was launched with the Voyager spacecraft in 1977, carrying sounds and images that depicted the diversity of life and culture on earth. 

“People started going crazy for whales,” Katy says. They were the subject of popular documentaries starring Jacques Cousteau and David Attenborough, while anti-whaling activism increased through the founding of the American Cetacean Society in 1967 and Greenpeace four years later. In 1972, pressured in part by environmental activists demonstrating outside, participants in the United Nations Conference on the Human Environment, in Stockholm, endorsed a ten-year moratorium on commercial whaling. It took another decade for the International Whaling Commission (IWC) to ban commercial whaling for all species. (Humpback whaling had been prohibited by the IWC since the 1960s, though Soviet whalers continued to hunt the species beyond then.) The IWC’s moratorium remains in place today, although Japan, Norway, and Iceland continue to offer scientific and commercial whaling permits.

After the IWC’s 1986 ban on commercial whaling went into effect, species like the humpback finally began to recover. Others, such as the right whale—so called because they were the “right” whale to kill on a hunt—remain critically endangered. Threats like collisions with ships and net entanglements put their plight in visible terms, but noise pollution is arguably the most insidious danger of all.

“Any successful animal in the ocean relies on sound for some basic life function,” says Christoper Clark, a bioacoustics researcher at Cornell and an expert on ocean noise. From mating to navigating and from finding food to maintaining social networks, cetaceans rely on sound to survive. “Light doesn’t go very far in the ocean, but sound travels remarkably well.”

Clark has experienced this firsthand. In 1972, he joined the Paynes on an expedition to Patagonia, where they were able to hear southern right whales snoring from 50 feet away. In the mid-nineties, Clark gained access to a Navy listening station and detected whale calls from 1,500 miles off. But for every whale he’s heard, he’s encountered far more human-powered sound.

Research has also shown that seismic blasts can disrupt humpback singing and migration behaviors. A paper published in 2014 found that the numbers of singing humpbacks off the coast of Angola decreased as seismic survey pulses increased in their breeding grounds. And an article from 2017 detailed how the migratory speeds of some humpbacks slowed in response to nearby seismic blasts.

Even ambient underwater noise has been shown to negatively impact whales. Following the 9/11 attacks, when global commercial traffic was largely halted, resulting in a reduction in underwater noise pollution, researchers detected fewer stress-related hormones in North Atlantic right whales. Today researchers say that the coronavirus shutdown may be allowing humpbacks to communicate more freely.

Humpback whales in the Caribbean
Humpback whales in the Caribbean (Velvetfish/iStock)

Within minutes of my meeting Knapp at the Culebra airport, it became clear that he’s known around town as the whale guy. The humpback pin on the sleeve of his blue shirt was the first indication.

“Six whales,” our cab driver said, smiling to Knapp in the back seat. “I saw six whales from the ferry the other day.”

Knapp wasn’t always into whales; his obsession grew gradually over time. After serving a year in Vietnam, he felt compelled to live and work on the ocean, which offered a pacifying contrast to his time in the service. Throughout his twenties, he took odd jobs on fishing boats and in dive shops in Saint Thomas and the Florida Keys. A few months in, Knapp’s captain told him about his experience piloting a boat for Jacques Cousteau, who was filming a documentary in Saint Thomas called The Singing Whale. Intrigued, Knapp bought himself a vinyl of Songs of the Humpback Whale.

He was deeply and immediately drawn to what he heard. After playing the record over and over, he said, “I started feeling like I hadn’t experienced everything I could from the recordings.” He committed himself to hearing the changing songs in person every season, like a superfan awaiting a musician’s next release.

In 1980, Knapp traveled to the Dominican Republic, where the Regina Maris, a sailboat operated by the Ocean Research and Education Society that conducted whale-research expeditions, was scheduled to set out from Puerto Plata. Knapp tried to secure a place aboard but was turned away. “I had nothing to offer them,” he said. “I had no knowledge of whales or academic credentials.”

After that unsuccessful trip, Knapp soon flew back to his home state of Connecticut. His obsession grew in New England where, as a member of the nonprofit Connecticut Cetacean Society (now known as Cetacean Society International), Knapp dedicated his free time to researching humpbacks, advocating for their conservation, and attempting to acquire his own hydrophone. If he couldn’t join an expedition, he’d find a way to listen on his own.

He spent many years traveling back and forth from Connecticut to the Caribbean, trimming New England hedges in the summer to fund his search for whale songs in the winter. He didn’t really know what he was doing, tossing hydrophones over the side of ferry boats and wading into the ocean in hopes that a whale was nearby. For the first two seasons, he only heard static. His breakthrough happened in 1984, during his first visit to the west coast of Puerto Rico. Knapp rented a spot on a small fishing boat and, using a cheap microphone stuffed in a plastic bag, finally heard singing.

He would spend close to a decade struggling to get a high-quality recording while traveling around the Caribbean, often camping on a beach at Tortola’s Brewers Bay in the British Virgin Islands and offering whale-listening expeditions to suntanned tourists. Then, in February 1992, after visiting the same location dozens of times, he was able to capture a seminal recording, “One Humpback Whale,” off the coast of Tortola.

Knapp sent the track to Katy Payne via a mutual friend, and Payne invited him to join her for Thanksgiving in Ithaca, New York, where she played the song for some friends from Cornell.

For Knapp, Payne’s endorsement validated a nearly 20-year odyssey. The meeting fueled his motivation to keep recording, and he bought a wrecked sailboat, the Compass, in 1996. In the years that followed, he released three albums—Rapture of the Deep, Listening to Humpback Whales, and One and Mostly One Humpback Whale—which featured recordings he made over 26 seasons in Tortola. In 2013, he left the British Virgin Islands and followed some friends to Culebra. 

There are umpteen ways to describe whale songs, from crooning love ballads to operatic anthems. “Some people say whale songs are soothing and peaceful,” says Knapp, who, for his part, has settled on two adjectives to express what he experiences. “The words I use have always been truthful and relevant.” Knapp finds an authenticity in whale songs that he hasn’t found in the human world. Where some people seek security in “gold castles,” Knapp says he finds it in the “audio truth of whale songs.” For him, listening to whales is akin to walking on a beach to clear one’s mind.

While many man-made sounds threaten the functions of sea life, the most recent—and among the most dangerous—come from the drilling industry. Today’s wells tap into pockets of fossil fuels deep beneath the seafloor. To find these pockets, exploration companies use big, slow ships, each equipped with more than a dozen seismic air guns that blast highly pressurized air into the water. The air immediately expands into a bubble before collapsing on itself and creating a sound that can penetrate miles into the earth. By analyzing how the sound bounces back, seismic-survey companies can map the subsurface. “This is the loudest sound we put into the water on a routine basis,” says Douglas Nowacek, a scientist who studies the link between acoustic and motor behavior in marine mammals at Duke University.

When the Trump administration lifted the ban on drilling in much of the Atlantic and Arctic Oceans in 2017, the decision was challenged by environmental groups, including the Natural Resources Defense Council and the League of Conservation Voters. In 2019, a federal judge ruled against the federal government, and the case is currently making its way through the Ninth Circuit.

While plans to open up drilling remain on hold, permitting for seismic surveys using air guns has continued to proceed. According to a spokesperson for the Bureau of Ocean Energy Management, these permits are still under review.

Catherine Wannamaker, an attorney at the Southern Environmental Law Center, suspects that the November election is a factor in this. “There’s an evaporating will for offshore drilling in the months leading up to an election,” she says, citing opposition from most Atlantic-seaboard governors, including Trump ally Henry McMaster of South Carolina. Many cities and towns have passed resolutions against offshore drilling because of the risk an oil spill would pose to tourism. Over the past few years, Wannamaker has noted a “cosmic shift in politics,” one that has seen many conservative politicians take up environmental issues. “I think Trump and the Bureau of Ocean Energy Management were surprised when folks like Governor McMaster vocally opposed offshore drilling and seismic testing,” she says.

Despite the holdup, Wannamaker and others worry that the permits may be issued at any moment, particularly if President Trump wins in November and no longer feels the need to appease his Atlantic-seaboard supporters. That worry was recently stoked by Tom Pyle, president of the American Energy Alliance and a Trump campaign adviser in 2016, who told E&E News on June 9 that “we need to do seismic everywhere.”

Accoring to Michael Jasny, director of the Marine Mammal Protection Project at the Natural Resources Defense Council, voters have to decide whether to side with the environment or against it. “This is a true moment of choice for humanity, not just on ocean noise but for every kind of pollutant,” Jasny says, citing the more than 100 environmental policies that Trump has dismantled or begun dismantling since taking office.

On March 3, while Knapp was on his boat, the owners of a local dive company called out to tell him they’d recently heard some singing during a dive around a nearby cay. Knapp hadn’t heard whales while underwater without the help of a hydrophone since he first moved to Culebra, seven years ago. The prospect of hearing humpbacks with our own ears, without a filter, was too tempting to turn down.

I won’t say that you hear humpbacks singing underwater. That doesn’t quite do it justice. The song is something you feel—first in your cranium, then in your chest cavity, and then in your limbs, where it tingles like a current.

Around 3 P.M., Knapp and I boarded his dinghy and made the short trip to the west side of Luis Peña Nature Reserve. We rubbed soap on our goggles to prevent them from fogging, slid our feet into fins, and tumbled into the water. 

Twenty feet beneath the surface, blue tang, parrotfish, and a large spotted eagle ray swam seemingly untroubled through a reef of staghorn and brain coral. Knapp instructed me to hold my breath, swim five to ten feet down, and stay completely still. I inhaled deep and dove. 

I won’t say that you hear humpbacks singing underwater. That doesn’t quite do it justice. The song is something you feel—first in your cranium, then in your chest cavity, and then in your limbs, where it tingles like a current. Listening through a hydrophone, it’s often difficult for untrained ears to decode the structures or identify individual singers, but as I floated underwater, the sound was intimate and emphatic, a profound lullaby hummed by a giant. In that moment, if you asked me to close my eyes and guess, I would have told you a 30-ton whale was passing just beyond my reach.

I resurfaced and dove back down a few more times to absorb this new sensation. As the humpback’s crooning rose and fell, I began to consider what Knapp meant when he called it truthful and relevant. Submerged and short on breath, I had no choice but to perceive the songs simply as they were: a present and self-evident expression of life, phenomena nearly lost to human exploitation. I thought about the generations after me, whose experience with these wonders may be limited to films and audio recordings, and who may never sense the kinship I felt while listening to the whale underwater. I braced for the challenge of rendering our encounter through words alone.