Federal Judge Orders Navy To Adopt Significant Mitigation Measures For Sonar Use

District Court Establishes Protections For Marine Mammals During Exercises
LOS ANGELES (January 3, 2008) – The U.S. District Court for the Central District of California issued today a preliminary injunction requiring a series of mitigation measures that will govern the use of mid-frequency (MFA) sonar by the U.S. Navy during training exercises in the rich biological waters off Southern California. In its order, the Court considered both the environmental benefits of mitigation and the feasibility of specific measures.
Calling key elements of the Navy’s mitigation scheme “grossly inadequate to protect marine mammals from debilitating levels of sonar exposure,” the court imposed the following additional limitations to protect marine mammals:
  • A 12 nautical mile no-sonar exclusion zone along the California coastline;
  • Expanded safety zone and shut down of MFA sonar when marine mammals are spotted within 2200 yards (approximately 2000 meters);
  • Pre-exercise monitoring for 60 minutes, each day in which MFA sonar is to be used;
  • Two dedicated, National Marine Fisheries Service-trained lookouts for monitoring during exercises;
  • Passive and dedicated aerial monitoring before and during exercises;
  • Helicopter monitoring for marine mammals for 10 minutes before deployment of active dipping sonar;
  • Power reduction of sonar when surface ducting conditions (i.e. conditions that enhance acoustic propagation) are present;
  • Exclusion of MFA sonar from Catalina Basin, an area of high marine mammal density.
“We have said from the beginning of this litigation that the Navy can meet its training objectives while substantially increasing protections against unnecessary harm to whales and other marine mammals,” said Joel Reynolds, director of the Marine Mammal Protection Project at the Natural Resources Defense Council (NRDC), which filed the lawsuit. “We are very pleased that the Court has agreed with us and has enjoined the Navy from conducting these exercises unless it takes the necessary precautions.”
The court order is here.

The high-intensity MFA sonar system can blast vast areas of the oceans with dangerous levels of underwater noise and has killed marine mammals in numerous incidents around the world. The waters off Southern California have some of the richest marine habitat in the country, and include five endangered species of whales, a globally important population of blue whales, the largest animal ever to live on earth, and as many as seven individual species of beaked whales, which are known to be particularly vulnerable to underwater sound.
On November 13, the Ninth Circuit Court of Appeals had ordered the Navy not to use high-intensity sonar in its future training exercises off Southern California until serious questions over likely harm to marine mammals could be resolved, and had ordered the District Court to impose mitigations on the Navy exercises sufficient to “provide adequate safeguards for the protection of the environment.”
In early August, a coalition led by NRDC won an injunction from the District Court, which concluded that without adequate measures to protect marine life, the Navy’s use of high-intensity sonar during training exercises likely violates federal environmental laws. The court wrote that the injunction was necessary given the “near certainty” that the use of MFA sonar during the planned Southern California exercises would cause irreparable harm to the environment, and characterized the Navy’s mitigation measures as “woefully inadequate and ineffectual.”
In late August, a three-judge motion’s panel of the Court of Appeals granted, in a split decision, a stay of injunction, allowing the Navy to use sonar during its exercises. That stay was reversed on November 13.
“Based on a careful weighing of the various interests, the Court has issued an order that significantly enhances protections for marine mammals in Southern California,” said Richard Kendall, a senior partner at the Los Angeles law firm of Irell & Manella, and co-counsel with NRDC in the lawsuit.
Mitigation measures were urged on the Navy months ago by the California Coastal Commission, which found them necessary to bring the training exercises into compliance with California’s coastal laws.
NRDC was joined in the lawsuit by the International Fund for Animal Welfare, Cetacean Society International, League for Coastal Protection, Ocean Futures Society, and Jean-Michel Cousteau.