TONGASS NATIONAL FOREST, Alaska — In this rainforest region of the Pacific Northwest, composed of coastline and hundreds of islands, falling raindrops can be heard softly hitting a still sea. Then an eagle calls to break the near silence.
Dr. Fred Sharpe began studying humpback whales in the 1980s, and now spends his summers on Baranof Island where he has developed research camps to record and analyze humpback vocalizations in the North Pacific Ocean. Scientists have studied humpback songs in the animals’ birthing grounds for decades, but the sounds they produce after migrating to their feeding grounds, like Alaska, are less understood.
Sharpe is not your archetypal researcher; he is scraggly yet beholds a sense of sincere humility. At the Society for Marine Mammalogy Conference in San Francisco in 2015, Sharpe arrived barefoot, and then scrambled to buy some shoes off the street so that he would be allowed in. One of his research partners in Alaska says he opts to sleep outside under a tarp, closer to the weather, rather than inside dry sleeping quarters. And he assembles a sound system of metal pipes and sheets to wake him in the case a brown bear passes close by. Sharpe is described as a celebrity in the whale community, and a force for good who helps others build relationships to the natural world.
Just off Baranof Island’s coast and beneath the ocean’s surface, Sharpe listens in as humpback whales (Megaptera novaelangliae) converse in low-frequency moans and whups, and high-pitched social chatter, like trumpeting and ahoogas. These marine acoustics are difficult to decipher, but researchers are recording these sounds in an attempt to comprehend their purposes.
“By studying the leviathans,” Sharpe says, “perhaps we can better understand how we can equitably get along [with the natural world].”
Through a life dedicated to fieldwork, and spending summers remotely in the Tongass National Forest, Sharpe and his research partners have developed a connection with the environment that runs deeper than statistical tests, journal publications and management policies.
“We built a relationship with the ocean in that particular corner of the world. And it’s a deeply, deeply personal relationship,” says Ph.D. candidate Michelle Fournet, who works with Sharpe. This connection with the ecosystem is driven by decades spent alongside whales, interacting with the flora and fauna around them, listening to the environment’s sounds or bathing in its silence.
“There’s no commerce. There’s no civilization,” Fournet says. “But there is humanity living on this rock, and observing the ocean.”
Sharpe and his team created a nonprofit, the Alaska Whale Foundation (AWF), in 1996 when North Pacific humpback whales were thought to number in just the few thousands, and were globally listed as endangered by the Federal Endangered Species Act. AWF includes many collaborating researchers and students, who gather in the summers near Warm Springs Bay at the Coastal Research and Education Center for a season of data collection. It takes 40 minutes by small plane or a full day by boat to travel from the state’s capital to the research center.
Humpback whales span the world’s oceans, and since commercial whaling became less common in the 1970s, many populations have successfully rebounded. In 2016, federal protections for humpbacks were revised, with many populations down-listed from their status as endangered. In 2016 the U.S. National Marine Fisheries Service officially divided global humpback populations into 14 segments: Four of these segments are still listed as endangered, one is considered threatened, and the other nine groups no longer warrant listing by the Endangered Species Act.
Most of the whales that migrate from their birthing grounds in Hawaii to feed off the coast of Alaska during the summer fall into the latter category, but other humpbacks that migrate here from Mexico are still considered threatened.
To Sharpe, whether listed or not, humpbacks warrant further research and conservation efforts.
To better understand the function of humpback whales’ sounds, Sharpe and Fournet try to engage them in conversation. This summer they will play humpback acoustic recordings back to whales, and try to translate their responses.
Acoustic playback is a practice used by researchers who study terrestrial animals, like birds and primates, but it’s not as common in the marine science world. Yet sound passes efficiently through liquid, making it an important sensory mechanism for many oceanic creatures, including cetaceans.
A study published in 2013 indicates that oysters use sound to detect a permanent spot to adhere and live. Larval fish may use sound to orient themselves and find their way back to the place where they spawned. And researchers are using acoustics in conservation efforts to estimate the population of critically endangered Vaquita porpoises off the coast of Mexico.
Underwater sound playbacks have been used in marine mammal studies of seals, sea lions and bottlenose dolphins, and Fournet thinks they have great potential for humpbacks. Already the method has been used for humpback research in the North Atlantic Ocean and off the coasts of Australia and Hawaii. By playing recorded ahoogas to a humpback in the ocean and documenting its reaction, researchers hope to unravel the meanings behind the various sounds. “This is the very first step in trying to figure out what these calls mean,” Fournet says.
However, documenting a whale’s reaction is difficult for many reasons. In Alaska, not only do humpbacks swim deeply and away from human observation, but the water through which the animals pass is infused with a high density of phytoplankton, causing low visibility.
The researchers plan to use a theodolite, a telescope-like instrument, to record whales’ exact locations by measuring space horizontally and vertically from land when the whales surface. While playbacks are being emitted, a theodolite can accurately document the location of a whale, transmit it to a computer program and store the animal’s movements. Fournet will also use a hydrophone to record responses from listening whales, and hopes to attach a camera tag to some to determine their precise behaviors during playbacks.
From there, she and Sharpe will interpret listening whales’ behaviors and sounds—an attempt to translate underwater whale tongue into human terms.
Last spring, Sharpe walked in Alaska’s state capital with large headphones covering his ears, a red tribal jacket hanging from his shoulders, a blue baseball cap cut into a visor and carrying a black garbage bag.
Halfway through our conversation at a cafe, the scientist got distracted by background noise. “I’m going to purchase a pair of ear plugs,” said Sharpe, who is highly conscious of protecting his most valuable research tool, his hearing. “I’ll be right back.”
When he returned, he took out his laptop. Continuing to slowly slip a decaf latte, garbage bag beneath his stool, he motioned toward his computer screen picturing an undulating sound map of a humpback recording he was analyzing. His left ear rested in his palm, which was marked with faded blue ink.
A few days later, Sharpe and his research team would retreat for the season to Baranof Island, a place that is “simultaneously noisy with life and completely silent,” as Fournet describes it. “And it’s really a beautiful thing because it actually is the marriage of humans and nature.”
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