Hearing is believing: Our oceans are getting louder
By Doreen Leggett
Chris Clark has made a life of listening to whales and was invited to a Congressional hearing to speak on the threat seismic testing for oil reserves poses to the highly endangered North Atlantic Right Whale.
The repetitive loud explosions, comparable to how the launch of the space shuttle sounds to bystanders, has been shown to make a mess of how whales communicate, feed and breed.
“It has been known since the time of Aristotle, and repeated and confirmed by scientific studies, that marine mammals depend on sound to survive,” the marine bioacoustics expert told the committee in Washington, D.C. in March. “The occurrences of seismic air gun explosions from surveys throughout the North Atlantic have been well documented and are essentially unavoidable.”
The Northern Hemisphere is lit up with noise and the North Atlantic Right Whales are on the precipice of extinction . Their southern counterparts live in a far quieter ocean which is otherwise quite similar, and are doing very well. That’s more than a warning sign, he said.
But right whale impact is just the well-publicized tip of the iceberg.
“Yes, I am worried about right whales, but the real impact is on fish,” Clark says. “They are a crucial protein. I don’t look at this as an esoteric matter.”
Clark’s opinion is well-regarded but not universal. Officials in the Trump administration have said that seismic testing to map beneath the ocean floor for oil and gas reserves would have negligible effects on the marine environment. That is why NOAA, the National Oceanic and Atmospheric Administration, recently gave five companies initial permission to conduct seismic tests.
But every governor from Massachusetts to Florida is strongly against testing, as well as leasing the ocean seafloor to oil and gas companies. The govenors are backed by states attorneys general, legislators, a host of non-profit and advocacy groups, as well as expert scientists.
“Much of the concern about high volume seismic air gun work underwater has focused on marine mammals, but potential damage to the entire food chain is a very serious concern,” says John Pappalardo, chief executive officer of The Cape Cod Commercial Fishermen’s Alliance. “Everything from tiny invertebrates to the fish we harvest could be seriously impacted by massive explosions of noise, over and over, on the ocean floor.”
Seismic airguns have been shown to cause harm and mortality for scallops, the most profitable fishery in the Atlantic Ocean. Seismic blasting also affects local abundance of cod and haddock, disrupts the distribution of many pelagic fish and negatively impacts zooplankton, critical in the marine food web.
“Fishermen in our organization have rallied against the idea of fossil fuel exploration in our region time and time again,” adds Amanda Cousart, policy analyst for the Fishermen’s Alliance.
People have known for centuries that fish communicate by sound; before Norwegians brought cod fishing to the United States they had talked about fish growling. Recently, Norwegians have done research showing that fish move out of noisy areas, survival of new spawn decreases drastically in those areas, and commercial fishermen catch 40 to 80 percent fewer fish when exploration is underway.
“Commercial fishes are highly dependent on a naturally quiet ocean,” Clark says.
Problems can reach even farther down into the food chain: a seismic survey off Tasmania killed all krill up to a half mile away.
“If seismic surveys are killing krill, we should be alarmed,” Clark says.
Clark has heard the clutter of manmade noise in ancestral spawning grounds of haddock and cod and when he had hydrophones in Massachusetts Bay to listen for whales, he heard what the Norwegians described long ago:
“Both cod and haddock males growl. We started picking them up on recorders off the backside,” he remembers.
Researchers have also shown that in each decade of the last half century, noise in the ocean – primarily from commercial shipping – has been doubling. Many whale migratory routes and feeding grounds are along the coast and among the noisiest areas.
Combine the noise of commercial shipping with those big seismic bangs, and a huge fuzzy ball of noise is created.
“You can’t listen to the ocean along the east coast and not be rudely aware of the fact that there are fog banks of noise being generated by us,” Clark says. “Seismic explosions are really modern versions of TNT.”
Humans consider sight key because on land it can grant the most perspective and lets us see so many things that are critical in our lives. Vision in the ocean is very different; even in the clearest water, one can see, at most, only several hundred feet. So ocean dwellers are adapted to rely on listening to and producing sounds for survival. Sometimes the sounds of whales can be heard across thousands of miles of ocean; something Clark did not experience until he was older.
He spent much of his younger years on the Cape. His maternal and paternal grandparents had homes in Truro and Wellfleet, which is how his parents met. Clark spent much of his time tromping around – being outside was where he was most comfortable. His time indoors was sound-based; there was no television, so radio was the center of the world, and his parents would have parties built around music. His dad was an amateur musician.
His parents split up before he was 10, and he was sent to St. John the Divine in New York City, where they sang every day in the largest cathedral in the world.
Those echoes, those reverberations, stayed with him.
“I never paid much attention to it until I listened to the acoustics from the ocean. I always wondered why it was that listening came so easily to me,” he says.
Clark started his college career in auditory engineering, focusing on hearing aids. Those studies morphed, and he became the founding director of the Bioacoustics Research Program at Cornell’s University Lab of Ornithology. From there it was a short jump to the ocean and a lifetime of traveling to places like the Arctic.
Early on he worked with the Navy, which relies on passive sonar - listening - to detect submarines. He was able to use their system to hear a blue whale singing across a distance of more than 1,000 miles.
“That was a holy shit moment,” he smiles.
There were other stunning moments. He remembers hearing a will-o-wisp sound, very faint, and wondered what it was. Turns out it was millions and millions of sea urchins feeding by scrapping algae off rocks and coral.
Jawdropping moments like that motivate efforts to protect the ocean environment, and there are solutions, he says. New technologies can drastically reduce the noise from ships – even slowing them down makes a difference. And there are technologies under development that can replace airguns.
It takes political and public will, he concludes, and that’s worth building because after all, “There are no known deaf marine mammals or fishes!”