Sounds Wild and Broken, page 32
Here off the coast of San Juan Island, the whales’ voices are like fine silk stitched into a thick denim of propeller and motor sound, clicks and whistles sometimes audible but often disappearing into the tight weave of engines. Through the hydrophone, our boat sounds like an unbalanced fan, a wobbly churn. Pistons merge into a low grind. The dozen other boats, all creeping along under engine power as they track the whales, interweave their throbs, whirs, and shudders. Combustion engines swaddle the whales in an inescapable, constricting wrap.
As the U-flotilla follows the whales, a rigid inflatable boat with soundwatch (for Soundwatch Boater Education Program) blazoned on its side weaves among the other boats. The three people on board wave to the gaggles of tourists gathered at the boats’ railings. Then a cruiser cuts in front of the path of the whales. The inflatable guns its outboard and arcs so that its path meets the miscreant. Some friendly hand gestures. A long pole delivers a leaflet. Boater education achieved. The inflatable returns to the cluster and bounces among the private motor boats, delivering more leaflets.
Since the early 1990s, Soundwatch has deployed small vessels in the areas most favored by the whales and their boating watchers, averaging more than four hundred hours of patrols per year. Over that time, the number of private and commercial boats seeking whales has increased, although the number coming close to the pods has decreased, perhaps as a result of regulations and volunteer guidelines that now reduce boat speed and closeness of approach. Unlike the in-your-face tactics of Greenpeace activists zipping in inflatables around whaling ships in the 1980s, Soundwatch aims to “politely initiate communication” and inform boaters about how to minimize disturbance of whales. They also collect data on boater behavior. Over the years, the most common violators of the “no-go” zones and boat speed limits are the skippers of private vessels, often those passing by on their way to go fishing or cruise the islands.
Feeling the engine throb through the soles of my feet on the boat’s deck, I sense that the chorus of chugging engines that partly encircle these whales, even if it meets “guidelines,” is hardly a neighborly welcome. Every turn of the propeller blade, no matter that we’re going slow and avoiding close approach, is a tap delivered to the vibration-sensitive fat-filled lower jaw of the whales. I “politely initiate communication” and query our genial captain about sound and the whales. “Naw, we’re not bothering them. If we keep our distance and go slow, no problem. Look at them, they’re playing now.”
In the distance, I see two huge ships, a container ship and an oil tanker headed north through the Haro Strait, likely bound for Vancouver, the largest port in the region. Our hydrophone’s portable speaker is too small to relay most of these ships’ low noise, but with heaphones on, I hear a continuous background rumble. These are two of the more than seven thousand large vessels that combined make more than twelve thousand transits through the strait every year. These range from bulk carriers, to container ships, to tankers, many of which are two to three hundred meters long. Large vessels also ply the waters west of the Haro Strait, headed to ports and refineries in and around Seattle and Tacoma. Each one of these vessels makes sound audible underwater from tens, sometimes hundreds, of kilometers. Unlike small pleasure boats that are usually moored at sundown, these large vessels make noise all night and day and are often most active and loudest at night. The largest container ships blast at around 190 underwater decibels or more, the equivalent on land of a thunderclap or the takeoff of a jet. In contrast, pleasure boats and passenger ships sound at about 160 and 170 underwater decibels, respectively. The decibel scale is logarithmic, and so the largest ships release thousands of times more sonic energy than small boats. The racket comes from many parts of the ships. Hulls stir the water into a low roar as they slice through. Fuel explodes in pistons and animates the metallic thrashing of engines as large as office buildings. Propellers spin so fast that water cavitates at the blades’ tips, creating air bubbles that blast as they then implode, smearing into a rumble and hiss. These sounds block both the echolocation and communication of the whales.
The “southern resident” whale community whose life centers on these waters cannot bear the noise, especially in the long run. Their population is in decline, likely headed to extinction unless the world gets more hospitable. In the 1990s, the community numbered in the nineties. Now they’ve dropped to the low seventies, losing one or two more animals every year without raising new calves. In 2005, they were listed under the Endangered Species Act. No single factor is responsible, but the interaction of shipping sounds, dwindling food supply, and chemical pollution is, for now, closing the door on their future.
These whales are the falcons of the ocean, rocketing down one hundred meters or more in pursuit of their nimble and speedy prey, the Chinook salmon. In the gloamy, silty depths, visibility is poor, but the fish’s swim bladders are bright in the echolocating beam, bubbles of sound-reflective air. Sound frequencies of boat noise overlap with the clicks that the animals use to echolocate and find their prey. Noise raises a fog, blinding the hunters. If a whale is within two hundred meters of a container ship or one hundred meters of a smaller boat with an outboard engine, its echolocation range is reduced by 95 percent. This is true worldwide but is an especially acute problem in and around the Haro Strait. Models of shipping traffic suggest that in this region, large ships account for two-thirds of the noise that mars the whales’ hunting. The remainder of the noise comes from smaller vessels, including the whale watchers that swarm the animals. Worldwide, small-boat traffic is only a sonic problem for whales close to shore and near busy ports. Over most of the oceans, it is the noise from large ships that fogs their hearing.
In air, we hear only a low groan from passing vessels. The sound is mostly transmitted down, below the waves, and the aerial portion is quickly dissipated. Under the surface, the sonic violence of powered boats travels fast and far through the pulse and heave of water molecules. These movements flow directly into aquatic living beings. Sound in air mostly bounces off terrestrial animals, reflected back by the uncooperative border of air to skin. Our middle ear bones and eardrum are specifically designed to overcome this barrier, gathering aerial sound and delivering it to the aquatic medium of the inner ear. Sound, for us, is focused mostly on a few organs in our heads. But aquatic animals are immersed in sound. Sound flows almost unimpeded from watery surrounds to watery innards. “Hearing” is a full body experience. For toothed whales, the embrace of sound is deeper. Ship noise envelops their sense of echolocating “sight” or “touch,” as if the noisy trucks rumbling past my window were pressing their tarry sounds into my eyes and skin. For most whales, and for many fish and invertebrate animals, eyes are only occasionally useful. In the abyssal depths, the animals swim in ink. Along coasts, the water is so turbid that animals see, at most, a body length ahead. Sound reveals the shapes, energies, boundaries, and other inhabitants of the sea. Sound is also a communicative bond. In the ocean, as is true in the rain forest where dense foliage occludes vision, sound connects you to unseen mates, kin, and rivals, and it alerts you to nearby prey and predators. In much of the ocean today, though, it is as if every rain forest tree had a ship’s engine blaring from its trunk.
If salmon were abundant, all this noise might not be a problem. Even a blinded falcon can snatch quarry from a teeming flock. But the Chinook salmon that compose most of the whales’ diet here are in crisis. Dams, urbanization, agriculture, and logging have cut off or degraded most of the freshwater rivers and streams in which the fish spawn and live out their first months. Pollution, fishing, and a warming ocean kill the smolts and adults as they complete their journey from fresh water, to estuary, to ocean, and back, a loop that takes three or more years. Chinook salmon numbers in this region have declined 60 percent since the 1980s, likely more than 90 percent since the early twentieth century. Pollutants add to the burden. The bodies of the whales in this region are among the most toxified of any animal. PCBs are a legacy of industry. DDT lingers from past agriculture. Flame retardants from people’s homes vaporize, glom on to dust, and are washed downstream. Partly because of this toxic burden, few calves are born to these pods and neonates usually die shortly after birth.
The combination of noise, declining prey, and contaminants is deadly. Under current conditions, models forecast, at best a fragile “southern resident” population. Any additional stress will send them to extinction. To increase the whales to their former abundance, Chinook salmon would have to be sustained at or above the highest levels known since the 1970s. Instead, salmon are dwindling. Robust mitigation of noise and contaminants could nudge the population up, but only if shipping were greatly slowed and a century of pollution were to be reversed. Hope lies in a confluence of actions. Models suggest that if we could reduce acoustic disturbance by half and increase Chinook salmon populations by one-sixth, the whale population could once again be viable. The “northern resident” population lives, for now, in quieter, less polluted waters, preying on more abundant fish, and are faring much better.
From 2017 to 2020, the Port of Vancouver enacted a voluntary slowdown of shipping traffic headed through the Haro Strait. For thirty nautical miles, large vessels slowed, adding about twenty minutes to the ships’ voyages. Ship noise increases with speed, and so dialing back the throttle lessens the cacophony in a place where the southern resident whales often feed. More than 80 percent of vessels complied with the project and hydrophones deployed around the strait found a reduction in noise levels.
Yet traffic increases yearly in the region, more than eliminating the quiet gained by shaving some noise from each passing ship. In 2018, crude oil exports from Vancouver jumped by two-thirds, mostly headed to China and South Korea. In 2019, the Canadian government approved an expansion that would nearly triple the capacity of the pipeline that supplies much of the oil from the tar sands region of Alberta. Vancouver’s port is expanding and, in 2020, was waiting for approval and funding for a 50 percent increase in size. In 2019, the nonprofit Friends of the San Juan cataloged more than twenty other proposals to build new or expanded shipping terminals for containers, oil, liquefied gas, grain, potash, cruise ships, coal, and car carriers in the region. If approved, these would increase traffic by 35 percent, not counting increased tugboat, barge, or ferry traffic. If increased shipping is blocked in Vancouver and if demand for shipped goods does not decline, traffic will be displaced to other ports, some in regions so far protected from heavy industry. For example, although proposals for new liquefied natural gas shipping terminals in and around Vancouver have been withdrawn or blocked, new gas pipelines and shipping routes are being developed in places with less opposition. Seven hundred kilometers north of Vancouver, the fjords that lead to the port of Kitimat are home to several species of whales living in relatively unpolluted and quiet waters. A liquefied natural gas terminal is under construction there that is slated to add seven hundred new large-vessel transits, a more than thirteenfold increase, not counting the powerful tugs that would accompany the tankers as they navigate rocky fjords.
The United States Navy also plans expanded exercises in the region, including the use of explosives and loud sonar. By its own estimates, across the Pacific Northwest coast, navy “acoustic and explosive” exercises, including those in the favored waters of the “southern residents,” will kill or injure nearly three thousand marine mammals and disrupt the feeding, breeding, movements, and nursing of 1.75 million more. The ocean falcons face both thickening fog and a navy that proposes to permanently cloud their eyes.
The whales in and around the San Juan Islands and the Haro Strait live in a constriction point for much of the trade that passes between Asia and North America, supplemented with some shipping from the Middle East and Europe. The vast majority of the consumer goods and bulk commodities that move between the continents do so on ships. I look around at my material possessions. Whales, either in the Haro Strait or perhaps off the coast of Los Angeles, heard the arrival of every item made in a country on the Pacific Rim: laptop, silverware, watering can, furniture, and car. Whales living along the Atlantic coast were immersed in the sounds of deliveries from Europe and North Africa: office chair, books, wine, and olive oil. Having lived most of my life inland, many hours’ drive from the sea, I have seldom seen or heard whales. But the whales hear me. They are immersed in the sounds of my purchases from over the horizon every day of their lives.
The converging shipping lanes around major seaports are focal points for a noise problem that extends across the oceans. In the 1950s, when Watlington recorded the humpback whales off Bermuda, about thirty thousand merchant vessels plied the world’s oceans. Now about one hundred thousand do, many of them with much larger engines. Tonnage of cargo has increased by ten times.
Ambient noise captured by hydrophones on the Pacific coast of North America has increased by about ten or more decibels since the 1960s, when the measurements started. By some estimates, the energies of noise pollution in the world’s oceans have doubled every decade since the mid-twentieth century. The noise is worse around the major shipping lanes that connect major ports across the northern Pacific and Atlantic, for example, but because sound propagates readily in water, the rumble reaches for hundreds of kilometers. When a large ocean-bound ship crosses the continental shelf, its sound shoots to the deep ocean floor, several kilometers down, then bounces up off the sediment and into the deep sound channel. This channel carries the noise thousands of kilometers. Like smoke in a room, the haze is worse close to the smokers, but spreads out from its sources to fill the entire room. Across much of the world, it is now impossible to measure the wind-stirred “background” levels of ocean sound. In a few places, shipping noise is less pronounced, especially in the southern oceans around Antarctica and in places where islands and seamounts act as sound shields.
Near to shore, small-boat traffic adds another, higher-pitched, layer of sound, as I discovered on the deck of the whale-watching boat. The number of recreational boats in the United States increased by 1 percent per year for the last three decades. In coastal Australia, the annual rate of increase in the number of small boats has recently reached up to 3 percent. The sound from these smaller vessels does not travel as far, but is the dominant sound source for many animals living in coastal waters. At close range, sonar—sounds emitted from shipboard devices to detect the seafloor, schools of fish, and enemy submarines—can add to these higher-pitched noises. Some naval sonar is loud enough to permanently damage the hearing of marine animals at close range.
Into this global mire of noise comes the loudest human noise of all, the percussive beat of our industrialized search for buried sunlight.
Like whales seeking their prey with echolocating clicks, human prospectors blast sound into the ocean, seeking oil and gas buried under ocean sediments. Ships drag arrays of air guns that shoot bubbles of pressurized air into the water, a replacement for the dynamite that was formerly tossed overboard for the same purpose. As the bubbles expand and collapse, they punch sound waves into the water, an industrial version of the fizz of snapping shrimp claws I heard on Saint Catherines Island. These waves spread in all directions underwater; those that go down penetrate the seafloor, then bounce back when they hit reflective surfaces. By measuring these reflections from the ship, geologists can not only see through the water column but also build a three-dimensional image of the varied layers of mud, sand, rock, and oil tens or even hundreds of kilometers under the seabed. Like a whale guided by the reflective ping of a Chinook salmon, oil and gas companies use sound to find their quarry. But unlike the click of a whale, these seismic surveys can be heard up to four thousand kilometers away.
The blast of an air gun emerges from a meter-long missile-shaped canister towed behind the survey ship. The sound can be as loud as 260 underwater decibels, six to seven orders of magnitude more intense than the loudest ship. The guns are typically deployed in arrays of up to four dozen. These batteries go off about once every ten to twenty seconds. The ship tracks methodically back and forth through the ocean, like a lawn mower, in surveys that can run continuously for months, covering tens of thousands of square kilometers. When the surveys encompass the open ocean, beyond the edge of the continental shelf, as they frequently do in this era of expanding numbers of deepwater oil rigs, the sound flows into the deepwater channel and, like shipping noise, spreads across ocean basins. In some years in the North Atlantic, dozens of surveys run at once and a single hydrophone can pick up the relentless sound of seismic surveys off the coasts of Brazil, the United States, Canada, parts of northern Europe, and the west coast of Africa. Seismic surveys are widely used wherever unctuous treasure might be buried under the sea, including Australia, the North Sea, Southeast Asia, the Middle East, and South Africa.
