Judge Limits Navy Sonar, Citing a Threat to Wildlife

Judge Limits Navy Sonar, Citing a Threat to Wildlife – New York Times

The US Navy has been barred from using its mid-frequency sonar systems in naval exercises off of southern California. The Natural Resources Defense Council sought the injunction.

The reporting on this issue has improved over time. It used to be that reporters did not distinguish between different sonar systems, and various environmental groups exploited that vagueness to argue that “Navy sonar” harmed cetaceans. Some sonar systems deployed by the US Navy, and other navies around the world, do have a record of harming certain taxa of cetaceans, but others do not. The article leads off,

A federal judge on Monday ordered the Navy to stop using medium-range sonar in training exercises off Southern California, saying that the Navy’s own assessments predicted that dozens of marine mammals, particularly deep-diving whales, could be harmed by the intense sound waves.

There are two apparent vaguenesses or inaccuracies in the above. It is unclear whether the reporter introduced them, or simply passed them on from a confused court. There is the distinction made about “medium-range sonar”; this is an odd way to refer to mid-frequency sonar systems, which are the ones implicated in various stranding incidents involving cetaceans. Then there is the “predicted that dozens of marine mammals, particularly deep-diving whales, could be harmed” part of the sentence. Does this refer to the number of individuals, and under what circumstances does that prediction hold? How many different species might be included? The previous sonar-related stranding incidents showed a particular sensitivity of whales in the genera Ziphius and Mesoplodon (the beaked whales, which are deep divers); are these the ones referred to here? It’s tough to tell.

There’s something else odd in the article. Consider these two paragraphs,

The Navy has argued that without training on this widely used system, sailors’ ability to detect enemy vessels is severely hampered. Active sonar, at various frequencies, has been developed over the past two decades as diesel engines on military craft became quieter and harder to detect with passive sonar.

Donald R. Schregardus, deputy assistant secretary of the Navy for the environment, said, “The decision puts sailors and marines at risk by ordering the Navy to stop critical antisubmarine warfare training while we complete environmental impact statements on our training ranges.”

Active sonar used for sinking subs dates back to World War II. Now, I doubt that any of the systems developed then are still in use by the US Navy, but “active sonar” as a class of equipment does have a much longer history. In fact, one of the beaked whale mass stranding events associated with mid-frequency sonar was back in the early 1960s (1962 or 63, IIRC), which considerably predates “over the past two decades”. But the real stinker in the first of those quoted paragraphs is, “as diesel engines on military craft became quieter and harder to detect with passive sonar”. That, coupled with the topic identified in the second paragraph of “antisubmarine warfare”, indicates massive confusion somewhere in the construction of the article. First off, most of the submarines of interest don’t use diesel engines. Unless we are concerned about Brazil’s submarine fleet, we aren’t primarily trying to detect the presence of diesel-powered subs. What has gotten much better in the way of submarine running gear is the propeller. Remember the flap over Toshiba trading with the USSR? What the USSR got was computer-controlled machining equipment that would allow them to manufacture submarine propellers to extremely fine tolerances, reducing cavitation and turbulence, and thus making their subs much, much quieter. That’s why the Navy has an interest in active sonar systems.

Wesley R. Elsberry

Falconer. Interdisciplinary researcher: biology and computer science. Data scientist in real estate and econometrics. Blogger. Speaker. Photographer. Husband. Christian. Activist.

3 thoughts on “Judge Limits Navy Sonar, Citing a Threat to Wildlife

  • 2007/08/08 at 2:49 pm


    My name is Petty Officer Shane Tuck, and I have some information on the Navy’s perspective on this issue. The Navy issued the following release regarding the court decision:

    Aug. 6, 2007

    Court halts Navy’s ability to train realistically off Southern California

    SAN DIEGO, Calif. – Navy officials say they are deeply concerned by today’s federal court ruling that prohibits the Navy from training realistically before deploying Sailors and Marines potentially into harm’s way.

    A U.S. district judge in Los Angeles granted a preliminary injunction — requested by the Natural Resources Defense Council and other environmental and animal protection groups — that bars the Navy from using active sonar during critical joint task force training exercises and composite training unit exercises through 2009 in the ocean off Southern California.

    “We are disappointed in the court’s decision and plan to appeal the imposition of an injunction,” said Mr. Don Schregardus, deputy assistant secretary of the Navy for the environment. “The decision puts Sailors and Marines at risk by ordering the Navy to stop critical anti-submarine warfare training while we complete Environmental Impact Statements on our training ranges.”

    Vice Adm. Samuel Locklear, the San Diego-based commander of the U.S. Third Fleet who oversees naval training in the Eastern Pacific, said, “To the extent this court decision prevents us from using active sonar, it potentially puts American lives and our national security at risk.”

    The integrated sonar training exercises are essential for naval units to complete before they deploy to the Western Pacific and beyond, including support for combat operations in the Arabian Gulf.

    The Navy has conducted similar exercises in the Southern California Operating Area for 70 years and has used similar active sonar technology for the past 40 years.

    “In all those years, not a single stranding or injury of a marine mammal has been associated with the Navy’s use of MFA sonar in the Southern California Operating Area,” Locklear said.

    The injunction is part of a lawsuit filed in March by the Natural Resources Defense Council and others against the Navy’s use of MFA sonar.

    “Active sonar is integral to anti-submarine warfare, or ASW, which is the Pacific Fleet’s top war-fighting priority,” said Locklear. “ASW is also the single-most difficult warfare area to master and maintain proficiency.”

    He added, “Today, dozens of countries – including North Korea and Iran – have extremely quiet diesel-electric submarines, and more than 180 of them operate in the Pacific, within reach of critical choke points and navigational sea-lanes. Active sonar is the best system we have to detect and track them.”

    “The Navy takes our responsibility to the environment and marine life very seriously, as demonstrated by our implementation of science-based, effective mitigation measures approved by the National Marine Fisheries Service,” Locklear said. “We are responsible environmental stewards while our sonar operators receive the realistic training and experience at sea they need.”

    To minimize the risk to marine life, the Navy takes a number of steps when operating at sea, such as posting additional lookouts specifically trained to detect marine mammals.

    The Navy is a world leader in marine mammal research, dedicating more than $14 million last year alone. In addition to the significant sonar-related research, scientists and veterinarians working with the Navy’s marine mammal program have made important advances in the care, diagnosis and treatment of marine mammal diseases.

    The Navy is preparing environmental impact statements for the Southern California Operating Area and other Navy range complexes where training and testing occur.

    For more information, I recommend viewing http://www.whalesandsonar.navy.mil/

  • 2007/08/08 at 8:00 pm

    OK, Shane, thanks for the full Navy response. I see that I was off in assessing the diesel-electric sub situation. Is there any further information on what exactly has led to the reduction in noise emitted by that class of sub? I still have my doubts that improvements in diesel technology make for the increased need for active sonar.

    Another good resource concerning the US Navy’s marine mammal research program is via the SPAWAR marine mammal program page and especially the annotated bibliography.

  • 2007/08/09 at 3:40 pm

    Hello again,

    Thanks for taking the time to view my post.

    I recommend researching air-independent propulsion systems (AIP).

    This information was found at

    As interest mounts in “Air-Independent Propulsion” (AIP) for enhancing the performance of small, defensive submarines, a serious new underwater threat is developing in littoral waters. Increasingly, smaller nations unwilling or unable to accept the high cost of nuclear power to achieve greater underwater endurance and longer range are turning to lower-priced and less ambitious alternatives that still offer significant operational advantages over conventional diesel-electric submarines. The best of the latter boats, such as the German-designed Type 209 or the Russian KILO, can remain submerged on battery at slow speed for periods on the order of three to five days. But now, several AIP schemes in development or already in operation can increase slow-speed endurance to as much as three weeks or a month. While still dwarfed by the potential of nuclear power, AIP offers diesel submarines a remarkable increase in capability.

    Read an older, but informative, article here

    Diesel-electric submarines using air independent propulsion can remain submerged for extended periods of up to two or three weeks, and unlike nuclear submarines, diesel-electric submarines can “bottom out” or rest on the ocean floor.

    Since shallow coastal regions are complex and noisy, the detection of such diesel-electric submarines is not possible using traditional acoustic methods.

    With air-independent propulsion, the fuel source and reused exhaust gases are combined in a closed loop to generate a submarine’s power. Current power plants include closed-cycle diesel engines and, more recently, fuel cells.

    This form of propulsion, while not used by the United States, Britain or Russia, is used by smaller navies. It is considered ideal for small vessels, is cheaper to operate and makes the submarine more difficult to detect.

    Diesel-electric submarines can provide a formidable challenge to current surveillance systems. The high ambient noise levels from local shipping traffic and marine life make passive sonar detection almost impossible in littoral waters.

    I also found this information at http://www.chinfo.navy.mil/navpalib/cno/n87/usw/issue_30/desi.html

    Diesel-electric submarines are prevalent in many third world countries, and what they lack in firepower, speed, and endurance, they make up for in quiet and stealth. They transit quietly at low speeds, can run on diesels at periscope depth, and are capable of running exclusively on battery power for eight to 24 hours (depending on speed and other factors).

    I’ll continue to research and see if I can find more specific information from offical Navy sources.


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