New international standards needed to manage ocean noise

Public Release: 1-Sep-2015
New international standards needed to manage ocean noise
Growing use of high-decibel seismic surveys to explore the ocean for resources poses increased risks to vulnerable marine life, experts say
Duke University

As governments and industries expand their use of high-decibel seismic surveys to explore the ocean bottom for resources, experts from eight universities and environmental organizations are calling for new global standards and mitigation strategies.

Their goal is to minimize the amount of sound the surveys produce and reduce risks the surveys and other underwater human noise pollution poses to vulnerable marine life.

Firms and agencies conducting the surveys would benefit from these new measures, the experts assert, because instead of having to navigate an assortment of rules that vary by nation or region, they would have a uniform set of standards to follow.

"In recent years, we've seen an increase in the use of seismic surveys for oil and gas exploration and research, and for establishing national resource claims on ever-larger geographic scales. Surveys are now occurring in, or proposed for, many previously unexploited regions including parts of the Arctic Ocean and off the U.S. Atlantic coast," said Douglas P. Nowacek, an expert on marine ecology and bioacoustics at Duke University.

•••••

Seismic survey impulses are among the loudest noises humans put into the oceans, and in some cases can be detected more than 2,500 miles away. The increase in ocean noise they cause can mask sounds whales and other species rely on to communicate, navigate, find food or avoid predators. Long-term exposure to the noise can also lead to chronic stress and disorientation in animals, and auditory damage.

•••••

Wider use of multi-client surveys could also cut risks. By collecting data simultaneously for two or more firms or agencies, these surveys significantly reduce the number of surveys required in a region, without forcing clients to share proprietary data. They've been successfully tested in Norway.

Emerging technologies could further reduce a survey's acoustic footprint. Many of these technologies, including the marine vibrator - which conducts surveys using a steady pulse of low-pressure sound waves over a longer period - are "not that far away from industrial scale use," Nowacek said.

•••••