The Current

Extremely Loud and Incredibly Wet

Rumbling tankers, military ops, oil and gas exploration—the ocean's turning into a noisy mosh pit and it's having a devastating effect on precious marine habitat

The ocean is getting louder for humpback whales and other marine animals.     Photo: Getty Images/iStockphoto

Some whales communicate across thousands of miles, since sound travels much further underwater than above. But that same fact has long had marine scientists worried that human noise pollution in and around our oceans hurts marine life. Underwater noise pollution grew significantly in lockstep with globalization and a wider reliance on transoceanic shipping. Sonar and seismic testing also harms many marine species in various ways, including through temporary or permanent hearing loss.

Add to this recent uptick in underwater oil and gas exploration, along with deep-sea mining, particularly in the Arctic, and the problems are magnified. Nor is the renewable energy boom exempt; offshore wind-turbine development generates significant noise, too.

A recent paper by the World Wildlife Fund lays out how human-caused noise is disrupting marine life—particularly whales, which are having a harder time finding mates and food due to the cacophony. The report also offers tools and strategies for mitigating the problem.

The report's author, Andrew Wright, concedes that ocean noise is just one of myriad human factors that are harming marine life. Some of these, such as overfishing, acidification, and water contaminants might be harming oceanic ecosystems more profoundly, but "resilience of a species to the effects of climate change may increase if its exposure to other pressures, such as underwater noise, can be reduced."

Way-Off the Jersey Shore

Problem is, just try telling energy companies that want to start developing the oil and gas deposits off the Atlantic coast to quiet down. Their first step would be to conduct seismic air-gun tests to re-quantify the deposits, which were last modeled decades ago using old technology. On February 27, the U.S. Bureau of Ocean Energy Management released its final Environmental Impact Statement, needed to evaluate the impact of these tests. The report details the many ways seismic testing could harm marine life and its suggested course would be to allow the testing, but with safeguards around when and how the tests would be done, to minimize biological harm.

The ocean conservation group Oceana had been quite vocal in opposing the seismic testing, characterizing the air-gun blasts as "100,000 times more intense than a jet plane engine," adding that they could be "emitted every 10 seconds, 24 hours a day, for weeks and months at a time." The group sent President Obama a letter, signed by 100 scientists, urging him not to finalize the impact statement. The American Petroleum Institute says oil and gas drilling off the Atlantic coast could create 280,000 jobs. Pointing to possible spills and disruptions, Oceana counters that 730,000 existing jobs in fishing and tourism are actually at risk.

While the bureau's report does not green-light seismic testing, it does open the door for air-gun testing to happen. (A current ban on offshore drilling along the Atlantic coast is set to expire in 2017.)

Mitigation Measures

Some of the WWF's report recommendations for mitigating noise pollution harm are really fundamental and long term, such as creating systems for improving energy efficiency, thereby lessening reliance on new energy development. But others are in line with efforts the International Maritime Organization is developing that, although they are voluntary, could lead to the wider use of low-noise propellers and hulls.

A number of techniques have also been developed that at least dampen noise generated by underwater construction done in relatively shallow water. These include bubble walls, which are pretty much what they sound like and reduce noise dampening it through air. Bubbles have also been shown effective at reducing drag on large commercial ship hulls, and the reduction of noise from ship engines has been a lucky byproduct of that practice.

Some offshore developers are also studying the effectiveness of screwing foundation pilings into the seabed, rather than pounding them into place.

The WFF has also closely studied Canada's Pacific North Coast and the ways in which ship traffic impacts whale behavior in that important corridor. That region would see significantly more ship traffic, in the form of oil tankers, if Canadian pipeline builder Enbridge gets permission to built a 730-mile pipeline to connect Edmonton with the port of Kitimat in northern British Columbia and create a means of moving tar sands oil to Asia. Despite feverish opposition from some coastal First Nation tribes, as well as environmental groups, the plan has been issued a tentative green light by a Joint Review Panel, assembled by Canada's Environmental Assessment Agency and National Energy Board.

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