Tag Archives: LFA sonar

Use of low-frequency sonar may expand in the future

The Navy has agreed to limit its use of low-frequency active sonar during testing and training exercises for the next five years. See the Associated Press story by Marcus Wohlsen in the Kitsap Sun.

LFA sonar involves loud blasts of low-frequency sound, which travel long distances in the ocean. It’s safe to say that advancements in this new technology are still being made, and this settlement is far from the end of the story. Most of the news reports I’ve seen have missed the point that this is a five-year permit under the Marine Mammal Protection Act, and the issue will come up again and again.

Years ago, the Navy planned to deploy LFA sonar on many of its ships, and it could return to those plans one day. For now, the Navy is planning to use it on four ships.

The story is complicated because it goes back to the original permit issued by the National Marine Fisheries Service. The permit, challenged by the Natural Resources Defense Council, would have allowed deployment of LFA over 75 percent of the world’s oceans. This settlement (PDF 360 kb) limits the deployment for testing, training and routine surveillance to the Western Pacific Ocean near Japan and The Philippines plus areas north and south of the Hawaiian Islands.

While it limits locations for testing and training, the agreement does not limit the use of LFA sonar during conditions of combat, potential combat or heightened threat conditions.

The settlement remains a trade-off, because there is no guarantee that marine mammals won’t be present in the areas of testing or training. One thing that would help is more research on the movement of whales and marine mammals, so the Navy can plan their operations with the least risk to sea life. With better understanding of both the technology and its effects of marine animals, the Navy could reasonably expect to expand its use of this technology to protect the nation’s interests. For details, check out the Navy’s LFA page.

Another issue worthy of attention is the proliferation of LFA sonar by other countries, including Canada, France and Great Britain.

Michael Jasny, an attorney with the Natural Resources Defense Council, said he would like to see the U.S. State Department work out agreements with other countries about when and how potentially damaging acoustic transmitters would be deployed.

“We’ve been trying to involve regional seas agreements, conventions and processes that would have guidelines for these systems,” Jasny told me. “In the Mediterranean, for example, habitat has been established for marine protected areas. What we’ve been advocating is the formulation of guidelines that would identify where sonar training should not occur. It would be ‘soft law” and would not impose an affirmative duty, but it would be a huge step in the right direction.”

To make sure there’s no confusion. LFA sonar is different from the mid-frequency sonar used by many ships since World War II. Mid-frequency sonar has been implicated in the deaths of whales, but the effects are much more localized. Mid-frequency sonar remains the subject of a lawsuit between NRDC and the Navy now before the U.S. Supreme Court.