SCOTUS vacates injunction against Naval use of sonar

Last week, the United States Supreme Court issued its first opinion of the new term: Winter v. Natural Resources Defense Council. This case concerned the Navy’s use of mid frequency active sonar, which transmits sound waves at various frequencies. This type of sonar is used in Naval exercises, including training and tracking of submarines. The Ninth Circuit Court of Appeals upheld a preliminary injunction imposing restrictions on the Navy’s sonar training, even though the record contained no evidence that marine mammals have been harmed by the activity. In arguing against the injunction, the Navy emphasized that it had used sonar during training exercises off the coast of California for forty (40) years, without a single documented injury to a marine mammal.

The injunction issued based on the Navy’s alleged violation of the National Environmental Policy Act of 1969, which requires federal agencies to the fullest extent possible to draft an environmental impact statement for every major federal action affecting the quality of the human environment. The areas of the injunction that were in contention required the sonar to be shut down when a marine mammal was spotted within 2,200 yards of a vessel, and the requirement that the sonar be powered down during significant surface ducting conditions, in which sound travels further than it otherwise would due to temperature differences in adjacent layers of water.

In reversing and vacating the injunction, the Supreme Court noted that the District Court and Court of Appeals held that when a plaintiff demonstrates a strong likelihood of prevailing on the merits, a preliminary injunction may be entered based only on a “possibility” of irreparable harm. The Supreme Court held that the preliminary injunction standard requires plaintiff seeking relief to demonstrate that irreparable injury is likely in the absence of an injunction. The issuing of a preliminary injunction based only on a possibility of irreparable harm is inconsistent with the court’s characterization of injunctive relief as an extraordinary remedy that may be awarded upon a clear showing that plaintiff is entitled to such relief.

The Supreme Court went on to note that even if the plaintiffs had shown irreparable injury from the training exercises, such an injury was outweighed by the public interest and the Navy’s interest in effective, realistic training of its sailors. The court cited testimony from several Naval officers who emphasized that realistic training cannot be accomplished under the two challenged for civic restrictions imposed by the District Court.