Citing national security interests, the U.S. Supreme Court ruled on November 12 that the Navy can once again conduct sonar training exercises, even if the tests harm marine life.
The 5–4 decision overturns restrictions that require the Navy to stop using sonar when marine mammals are spotted within 2,200 yards of its vessels.
The Navy uses sonar technology to send underwater sound waves at frequencies between 1 kHz and 10 kHz. Gauging the time it takes the acoustic waves to echo off an object — enemy submarines in a combat situation — provides a way to determine the distance to the target.
Environmentalists, represented by the Natural Resources Defense Council, say the loud blasts can cause permanent hearing loss, decompression sickness and major behavioral disruptions in sea animals. The NRDC claims that the damage may go undetected because some of the affected creatures spend little time at the ocean’s surface (“Bad Bubbles: Could sonar give whales the bends?” SN: 10/11/03; “Stranded: A Whale of a Mystery, SN: 7/19/08).
Following the court’s decision, the Navy can conduct their training exercises off the southern California coast, even if sea lions, dolphins or whales are spotted, though they still must cease activity if sea life is spotted within 200 yards, in accordance with a previous self-imposed regulation.
The court’s majority opinion contends that the public’s greater interest is preparing the Navy to protect the United States from enemy submarines by running realistic training exercises, outweighing the public’s interest in protecting sea life. Written by Chief Justice John Roberts, the majority opinion states that “active sonar is the only reliable technology for detecting and tracking enemy diesel-electric submarines, and the President — the Commander in Chief — has determined that training with active sonar is ‘essential to national security.’ ”