http://www.sfbg.com/2010/04/13/drowned-out
The reason I posted this is because it has implications for dolphins as well as whales. Dolphins are found in the same tropical waters as coral reefs. DeeVon
San Francisco Bay Guardian
Drowned out
GREEN ISSUE:
Endangered whales may be threatened by a noisy side-effect of globalization
04.13.10 – 4:24 pm | Rebecca Bowe | (0)
Ships create a two-pronged threat to whales, creating noise pollution and sometimes ramming them to death
PHOTO BY JOHN CALAMBOKIDIS/CASCADIAN RESEARCH COLLECTIVE
rebeccab@sfbg.com
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.
Special thanks to Richard Charter
