No one ever said the search for fossil fuels in increasingly hard-to-reach places was easy. As part of their quest to keep the oil and gas industry on top, drilling companies blast sound waves into the ocean depths with crazy-powerful airguns, looking for new scores. Sound travels through water quite well, far better than light, and is capable of covering great distances. So it’s a useful tool for humans looking to mine the sea; but for the whales, dolphins, and fish that live and swim in the blast radius, the noise is more than an annoying nuisance. It can be a killer.
The airguns are capable of detonating every 10 to 12 seconds and are about as loud as dynamite (which, it so happens, was how the industry used to perform these acoustic treasure hunts). According to the Natural Resource Defense Council -- which publishes OnEarth -- a single seismic survey can interrupt the calls and singing of endangered fin and humpback whales over an area of at least 100,000 square nautical miles. For reference, if the array were in Washington, D.C. (and the country was underwater), it could put whale voices on mute from New York to North Carolina.
Of course, it’s not just about cetacean songs. Biologists from Cornell call this underwater noise pollution “acoustic smog.” Studies have shown that it interferes with the ability of many ocean dwellers to reproduce, hunt, avoid predators, migrate, and communicate. And in extreme cases, the noise can kill some animals outright from shock. The practice affects at least 55 marine species, including several endangered whales and 20 commercially valuable kinds of fish. Do you hear the rumbling now? It’s our stomachs.
Oil and gas companies cruising around with their boom boxes blaring is a particular problem in the Gulf of Mexico, where sea life is still trying to recover from the Deepwater Horizon oil spill. That’s why, following the 2010 disaster, a coalition of environmental groups (including NRDC) sued the Interior Department and representatives of Big Oil to force them -- under the Marine Mammal Protection Act and the Endangered Species Act -- to reconsider their methods of sonic testing. Just last week, a major settlement agreement was reached.
As the oil and gas industry waits for the government to complete an environmental review of seismic exploration (could be a while…), it has agreed to:
- Prohibit airgun blasting in biologically important areas -- places like DeSoto Canyon, which scientists have deemed crucial for sperm whales, Bryde’s whales, and the Gulf’s only resident population of large baleen whales
- Prohibit airgun exploration in coastal waters during the main calving season for bottlenose dolphins
- Enforce mandatory minimum distances between surveys
- Extend the government’s existing mitigation measures to cover the entire Gulf and add manatees to the list of species protected
- Use passive listening devices to detect the presence of affected species when visibility is reduced
- Compel industry to undergo a multi-year R&D project to develop and test a lower-impact alternative to airguns known as marine vibroseis, or marine vibrators (easy now!)
- Evaluate whether airgun surveys are unnecessarily redundant in intensity or distribution
“The BP drilling disaster provided graphic images of oiled marine mammal carcasses, delivering tragic proof of the harm oil companies can do to Gulf wildlife by cutting corners,” says Cynthia Sarthou, the executive director of the Gulf Restoration Network in a press release. “This agreement won't magically make drilling safer, but it will increase the chances that our amazing whales and dolphins can continue to recover. I think the dolphins are doing backflips today.” That is, if they can hear the news over all that racket.
Image: Richard Fisher