Drowned out

Pub date April 13, 2010
WriterRebecca Bowe
SectionGreen City


GREEN ISSUE The tiny, rigid-hull inflatable boats that researchers at Scripps Institution of Oceanography use for whale tagging are a mere fraction of the size of the blue whales they are deployed to search for. But Scripps PhD candidate Megan McKenna says there’s no reason to worry about the mammoth creatures — which can weigh as many tons as 27 elephants put together — bumping up against the boat when she reaches overboard with a pole to tag them.

“They’re just pretty mellow, I guess,” McKenna says. “There’s no flailing or anything. Some barely even notice that we’re there.” For two summers, she’s ventured out in pursuit of the endangered whales, popping short-term monitoring tags on them to learn how they behave when massive cargo shipping vessels motor past.

It’s an important question for a couple of reasons. Government funding was provided for the Scripps study after two blue whales were struck and killed by commercial shipping vessels in 2007, tragedies magnified by the fact that the marine mammals are still struggling for survival. If even two die in such collisions every few years, the entire species could be imperiled, McKenna says.

At the same time, a less-understood phenomenon has marine scientists worried that the deep-blue giants’ survival is being undermined by a subtler problem, that Jackie Dragon of San Francisco-based Pacific Environment likens to “death by a thousand cuts.” Noise generated by whirring ship propellers registers at the same frequency as the low tones whales use to communicate and forage for food, and researchers are concerned that the constant interruption is affecting their ability to engage in basic survival behavior.

Put together with an array of concerns including chemical pollution, marine debris, over-fishing, and ocean acidification, noise pollution is just coming onto the sonar of local marine sanctuary councils and federal environmental agencies, and proposed solutions are only in the fledgling stages.

Pacific Environment is one of several environmental organizations advocating for shipping vessels to travel at slower speeds, a quieter practice that also reduces the chances of hitting a whale. Despite growing evidence that noise pollution and ship strikes pose big problems for the planet’s largest mammals, it’s likely to be an uphill battle in an growing global industry where time is money, and on-time delivery is paramount.

Endangered whales favor the Gulf of the Farallones and Cordell Bank sanctuaries, not far from San Francisco, so Pacific Environment has chartered a catamaran to take ecologically-minded whale watchers out to what Dragon dubs the “Yosemites of the sea.” Using hydrophones, they capture the deep, rumbling whale calls. They also pick up noise generated by commercial ships, whose designated lanes cut directly through the protected areas.

Under just the right ocean conditions, the low, eerie mating call of a male blue whale off the coast of California can be heard by a female off the coast of Hawaii. “That just has to do with the physics of sound in the ocean,” McKenna explains. “They’re vocal animals. You can think of sound in the ocean as our vision. Sound travels so much better in water than light does, so it’s really an acoustic environment that they’re living in.”

McKenna is working with whale researchers John Calambokidis of the Cascadia Research Collective and John Hildebrand of Scripps Institution. While they’ve observed that some whales linger at the surface longer than usual after a ship has passed, leaving them vulnerable to a strike, there are no conclusive results as of yet.

To explain the noise impacts, Dragon uses an analogy of trying to communicate in a crowded bar where it’s difficult to hear. “In the ocean, sound is king,” she says. “This chronic, noisy, foggy environment … has a masking effect. It might mean whales will not be able to navigate correctly, or may not be able to communicate with mates or offspring.”

The Gulf of the Farallones National Marine Sanctuary supports a rare concentration of blue whales, partly because the water is rich in nutrients, biodiversity, and tiny, shrimp-like creatures called krill. Blue whales and endangered humpbacks forage there from April through November, the colossal blues consuming an astounding 4 tons of krill each day.

At an April 8 joint meeting between the Gulf of the Farallones and Cordell Bank marine sanctuary advisory councils, the groups discussed creating a working group — bringing together stakeholders from the U.S. Coast Guard, shipping industries, and others — to establish a set of recommendations for how to regulate noise pollution in the sanctuaries.

“The purpose is to better understand the issue from the standpoint of the sanctuary,” explains Lance Morgan, who chairs the Cordell Bank council. “Ideally, we’d produce a report that says, here’s what we think the issues are.”

Yet Morgan acknowledges that it won’t be easy to get the federal government to impose new sanctuary regulations since there are still so many outstanding questions. “We’re learning a lot about the acoustic environment,” he says. One concern is whether whales are actually able to perceive the sound of the giant shipping vessels, he notes, since the environment has become so noisy. If they can’t hear the ships, they’re at a much higher risk of collision. “We certainly know we can drown out whale calls in certain situations,” he says, “but what does that mean in the long term?”

There are around 14,000 blue whales left across the entire watery globe, according to the most optimistic estimates, just a sliver of the estimated 300,000 that lived before they were nearly harpooned to extinction during a ruthless whaling era. Scientists are encouraged that their numbers have climbed since the mid-1960s when they were listed as endangered.

Yet even with this mild success story as a backdrop, there is growing concern about potential long-term effects of underwater industrial noise. Navy sonar, military air guns, and blasts from seismic surveys all contribute to the problem at varying frequencies. The collective din of ocean noise has doubled every decade since the 1950s, and the shipping business is only expected to grow.

Maersk, the world’s largest shipping company, runs weekly container ships from Hong Kong to ports in Oakland and Long Beach, a journey lasting more than two weeks. Getting the goods there on time is “the most important thing to our customers,” says Lee Kindberg, the company’s environment director.

The container ships arrive crammed full of everything from electronics — which require special climate-controlled containers — to clothing, bath products, household items, and pharmaceuticals. Perishable items are transported in refrigerators, consuming a third more energy and powered by auxiliary engines. Up to 8,000 containers can be packed onto a single ship, and the average vessel size has expanded around 20 percent in the past five years. More than 90 percent of the world’s traded goods are transported by water, with shipments on container vessels increasingly rapidly.

If ever there was an icon for globalization, and all that the buy-local and sustainability movements rail against, it would be a diesel-powered container ship transporting heavily packaged stuff halfway across the globe.

“Clearly it’s not a good thing if we hit a whale,” Kindberg says. Undersea noise pollution “is certainly an issue that we’ve been made aware of. But there doesn’t seem to be any real clarity as to what the impacts are,” she notes. Maersk would support certain speed reductions to protect the whales, Kindberg says, but “if you slow down in one place, you need to speed up someplace else, and that can take more fuel.”

Regulations in certain waters off the eastern seaboard already require ships to move at slower speeds to minimize harm, and Kindberg says Maersk has voluntarily opted to operate at slower speeds to reduce greenhouse gas emissions (it saves on fuel costs too). But when going along at 10 knots (around 11 m.p.h.), the speed environmental organizations say is safest for marine mammals, it’s harder to maneuver the ship, Kindberg says. Sailing around the marine sanctuaries is not an option in California, she adds, since ships have to pass through them to get to the ports.

Other efforts to solve the shipping-noise problem focus on ship design. “We’re building larger and larger ships, and they’re getting noisier and noisier,” says marine ecologist Leila Hatch of the National Oceanic and Atmospheric Administration (NOAA), who studies the effects of underwater sound on marine mammals.

The International Maritime Organization accepted a plan in 2008 to form a working group and to pin down guidelines for making commercial ships quieter, according to Hatch. Although the guidelines aren’t enforceable and are unlikely to be implemented any time soon, she sees it as an opportunity for a win-win scenario. If new ships featured a design with more efficient propulsion, they could be quieter, cheaper to operate, and more energy-efficient — which would also improve the air-quality problems associated with giant commercial ships.

The California Air Resources Board, meanwhile, initiated an effort last year for a program to get commercial vessels to slow down near the coastline, a bid to reduce emissions of smog-causing chemicals and the greenhouse gas carbon dioxide. Not much is happening on that front to date, but such a program could have the positive side effect of quieting underwater noise.

Hatch has been trying to quantify the decline in hearing ranges for marine mammals as the seas grow increasingly crowded with larger, noisier ships. “Much of the space they used to have is taken up by shipping noise. What is that likely to mean in terms of their ability to communicate effectively and find food?” she asks.

To find answers, she’s engaged in a research project at the Stellwagen Bank National Marine Sanctuary off the coast of Massachusetts that blends GPS ship-tracking data with profiles from sound-monitoring devices planted on the sea floor. Results suggest that whales’ communication ranges have diminished by 80 percent in some places.

There are few easy answers, however, since scientists are still trying to piece it all together. One certainty is that “we’re changing the environment they’re trying to live in,” notes McKenna, who says she now finds herself wondering if she’ll end up purchasing something that’s packed onto a massive containership when she spies one out on the horizon. “To what degree is it impacting them?”

She can’t say exactly, and that’s part of the problem, because the global shipping industry wants to see some concrete facts before the battleship can be turned. In the meantime, Kindberg says the captains helming Maersk line are just trying to avoid hitting the whales.