Scientists have long used seismic surveys to explore the ocean floor for oil and gas deposits. To conduct a seismic survey, high-intensity pulses of compressed air are fired into the water every 10 seconds, for anywhere from a few days to several weeks. The underwater cacophony creates echoes that scientists then monitor for key geological clues about the seafloor, including areas that could be primed with oil and gas deposits.
Research published last week in the journal Frontiers in Ecology and the Environment calls for a new set of standardized rules for oil and gas seekers to abide by while conducting these types of seismic surveys in order to minimize risk in the Arctic. The study authors recommend that noise pollution from seismic research be globally recognized as just that—pollution.
As beneficial as seismic surveys are to oil and natural gas-seekers, their effects on marine life—whales especially—is worrisome. The gentle giants of the sea use sonar to communicate, locate food, and reproduce. Just one airgun array trawled behind a ship during a survey can disrupt whale behavior within a 100,000-square-nautical-mile area, according to research.
The endangered fin whale, for example, has been shown to become silent and abandon feeding and breeding within a 10,000-square-mile area surrounding seismic surveys; and beaked, humpback, and melon-headed whales have been found beached on the coasts of Mexico, Brazil, and Madagascar—all near seismic activity well. Seismic surveys are hurting the fishing industry, too; catch rates for commercial species like cod and haddock have dropped by up to 80 percent near survey sites.
Although the European Union recognizes seismic noise as a pollutant, researchers recommend that standards and monitoring programs for ocean noise levels be added to the International Convention on the Prevention of Pollution From Ships, which safeguards against marine pollution. Holding ocean noise up to global standards could further studies into the long-term effects of seismic noise on marine life—like chronic stress and auditory damage—and pinpoint particularly sensitive marine areas where seismic noise could be especially harmful to the ecosystem and should be avoided altogether.