Noise in the Oceans: Military Sonar

By William Rossiter

Active military sonars can harm whole populations of whales and dolphins. The latest evidence, sparse as it is, suggests that cetaceans may have learned to fear mid-frequency active sonars, and may flee from them when still very distant. That may deny them critical habitats, travel routes, and significant behaviors, and may even force them ashore. The cetaceans too close to the starting sonars may behave in ways that debilitate and kill them, or be directly injured by the sound. A short while ago this would have been hyperbole. Today it is a reasonable and precautionary assertion based on a consistent trend, made with the best scientific information available. The tragedy is that there are few ideas of what to do about it.

It is prudent to act on the trend. Events linking population-level physical and behavioral impacts with naval sonars continue, and there are enough "smoking guns". CSI has been involved with the noise issue since 1996, when the Low Frequency Active Sonar (LFA) surfaced. We are again co-plaintiffs with Natural Resources Defense Council in a lawsuit against mid-frequency (MF) sonars, LFA legal actions continue, and we are advocating on many other anthropogenic noise issues, like shipping and seismic surveys. CSI focuses on noise issues because it is a rapidly growing problem that needs research and solutions.

Many scientists and authorities agree with our concerns. A January scientific workshop on the "Risks Associated with Marine Acoustics in the Southern Ocean" was held at the University of Cadiz in Spain. In February a British government interagency committee on marine science and technology called for the expansion of existing noise treaties and activity permits, and wider cooperation between relevant groups, recognizing that naval, oil and gas, and shipping activities in UK waters should be mapped and monitored to protect sensitive marine life. The report will drive a marine bill later in 2006. The International Whaling Commission's Scientific Committee, The World Conservation Union, the European Parliament and the United Nations have recognized the threat intense ocean noise poses to marine life. All urge caution with anthropogenic ocean noise use, while stepping diplomatically around direct confrontation with national military forces. CSI believes we need less diplomacy and more cooperative action.

36 whales stranded alive on North Carolina's Outer Banks in January 2005. The final NMFS report of this "very rare" live stranding of three species absorbed the time and expertise of some of the best specialists in the world, and concluded that the cause "is not and likely will not be definitively known." This event was not a smoking gun. What is known is that 33 pilot whales, two pygmy sperm whales and a minke whale live stranded in one weekend, unique in North Carolina and certainly an "Unusual Mortality Event." The whales were in reasonable health, although they had no recent food in their stomachs. The minke whale was emaciated, perhaps having been separated from its mother. None of the whales showed physical evidence of traumas associated with acoustical sources.

Active mid-frequency naval sonars were used about 50 miles away two days prior, in normal operations with mitigation protocols (which noted no whales). No one knew where the whales were when they heard the sonars, so the values of loudness, ducting, reverberation and reflection could not be calculated. Combining caveats with coincidence, the report could "not preclude behavioral avoidance of noise exposure." Mass strandings remain our pitiful cue that something has happened, but how many do we need to decide something must be done? Assuming every mass stranding to be sonar-related is wrong, but they must be checked.

Four Cuvier's beaked whales stranded and died on Spain's Almeria coast in late January 2006, definitively victims of active military sonars. Thanks to the rapid and expert response by the Unit of Cetacean Research at the Veterinary School of the University of Las Palmas on Grand Canary Island, the necropsies of the two females and two males quickly found them to be well fed yet suffering from "Gas and Fat Embolic Syndrome". One female was lactating; if it was her calf reported near shore the calf is not likely to have survived either. The Canary Islands' team was led by Professor Antonio Fernández, the same expert brought to London to check the bottlenose whale.

Their necropsy report concluded that "the most likely primary cause of this type of beaked whale mass stranding event is anthropogenic acoustic activities, most probably antisubmarine active mid-frequency sonar used during the military naval exercises." Several mass beaked whale strandings have coincided with normal naval mid-frequency active sonar use, such as in the Bahamas, 2000, and Canary Islands, 2002 and 2004. Sometimes the harm comes from fear or panic induced by the sonars, apparently causing whales with gas-saturated tissues to surface too quickly. However it happens, animals are now known to suffer and sometimes die after exposure to military sonars. How many beaked whales actually died no one knows. We only know of the few that get to shore before dying, and only a very few of those have been studied with the necessary speed and sophistication.

Cuvier's beaked whale courtesy of Colin MacLeod

HMS Kent, a British Royal Navy Class 23 frigate, was perhaps 200 miles south when the stranding in Spain occurred. She had left Portsmouth under a new command on 16 January for a short Mediterranean deployment, to conduct gunnery drills and firings off Gibraltar as part of the training package for students on the Principal Warfare Officers Course. Britain's Ministry of Defence admitted that the Kent had used active sonars at least two days prior to the stranding.

The Kent is equipped with the Type 2050 mid-frequency active sonar system, somewhat comparable to the US Navy's mid-frequency sonars, AN/SQS-53C and AN/SQS-56. These have been implicated in several mass stranding events of beaked whales and extreme aversion behaviors by marine mammals in Haro Strait, Washington State. The only comparisons that count are what they sound like to whales, and why that sound drives the animals from critical habitats or behaviors, or panics them into making mistakes that kill them. To humans these very loud sonars sound like screaming banshees as they reverberate through the water, bouncing off the surface, bottom, and thermoclines.

After the Kent event the Royal Navy announced that warships are to be equipped by 2008 with a scanning system as likely to fail to find marine mammals as any other mitigation used today. Assuming whales, dolphins and porpoises make a lot of sounds, which they do not, the £2.5m system will search for cetacean sounds picked up by standard passive sonars. Even if the whales and dolphins are as noisy as hoped, dolphin clicks fade over short ranges, and all but the loudest cetaceans won't be audible beyond two miles. The cetaceans will still hear the active sonars from many more miles away. If it does scare them they can be expected to be more silent, and the Royal Navy vessel will be confident nothing is near as it zaps them.

Sonar training occurs everywhere, on directed cruises like the Kent, passages through certain environments like the Shoup, even just checking equipment at the beginning of a deployment, as near bases in Japan. The massive RIMPAC 2006 exercise will run for a month beginning in late June. Last year about 200 melon-headed whales may have been driven into Hanalei Bay, Hawaii by RIMPAC 2005 vessels that were just checking equipment. Controversial training ranges are also planned. The Navy must have been surprised to receive over 40,000 pages of comments on their planned East coast Under Sea Warfare Training Range (USWTR). Along with very detailed responses by some experts, NOAA and the Marine Mammal Commission found serious flaws. All are now public records, and together provide the most current and richest resource on mid-frequency sonar issues available today.

The assumption that cetaceans must be close to sonars to be harmed is flawed. Many herding mammals can be brought to a stampede by one animal's reactions. Any animal behaviorist will concur that whole populations of social animals can be driven to escape something feared only by a few; others will follow because they recognize the fear, not the cause. They may also learn what caused the fear, passing it on. Survivors may never return; scientists who studied the Bahamas beaked whale population never saw any of them again after the 2000 sonar-related mass stranding.

The evidence from the beaches is that whales and dolphins may be fleeing distant active sonars. That fear may also cause beaked whales and perhaps other species to surface too quickly, leading to debilitating traumas. These whales may drift ashore days later to die. If unable to eat cetaceans may die of dehydration before starvation, as most of their water is in their prey. All they have to do is stay afloat to breathe. For example, decades of beaked whale information depended on strandings, as they have always been very elusive at sea. They kept stranding far away from assumed ranges. Either they were everywhere or sick animals had drifted long distances. In 1983 a net-entangled humpback stranded on Cape Cod, almost all blubber used up. The Canadian fishing net on his tail kept him from anything but drifting for several hundred miles down the coast. He may have drifted for a year.

Do you want to do something to help? Here's one of the mysteries we all need solved, and you don't have to be a scientist to do it: Start with where and when the whales stranded, and search for ways to get information on the ocean in that area over a the days before the stranding. Everything you need is on the Internet. Assume the injured whales either drifted with the currents, or swam away from whatever caused the problem. Backtrack both possibilities at 12 or 24 hour intervals, factoring in ocean and weather information available from the Internet. Your goal is to find out where these whales might have been when they were hit with whatever finally caused the injuries; look for probable habitats (like steep bottom contours) and routes between them. The longer the time the larger the area. The next question may be harder: were there any naval vessels near those areas using active sonar?

What will you do with the answers? You'll help whales: If you send the information to CSI we will involve you in our effort to put the pieces together with expert help, and help develop policies and solutions to stop killing these whales with sonars.

Whales and national security; is it possible to have both? It comes down to this: Does national security have more value than whales, or is a balance possible? As the military is pressed to a wall of their own making will they adapt or fight? They are adapting at the moment, supporting studies to flag cetacean hot spots, changing some operational protocols, and developing mitigations based on avoiding cetaceans by trying to sense them in time. The mitigations, little changed for a decade, are simply inadequate. Michael Stocker of SEAFLOW may have a mitigation that deserves a chance: He correlated the sudden surge in sonar impacts with the very unnatural sounds today's digital sonars make, in contrast to more natural signals from older analog sonars. Could analog mid-frequency sonars meet military needs? CSI has found the Navy's invalid reluctance to be based on favored programs and profit making contracts for current equipment, not on the reality of whether the mission could be accomplished with possibly more whale-friendly equipment.

Blainsville's beaked whale calf courtesy of Colin MacLeod

You should be painfully aware that if the Navy cannot comply with the laws they will fight to change them. Recall that the Navy led the Department of Defense in a charge that gutted the Marine Mammal Protection Act and many other hard won environmental laws, rather than be told what to do. We all lost far more than they gained, but that's war and they're good at it. When it serves the Navy the solutions come easy, like slower vessel speeds in critical areas, command approval for some sonar use, and timely reporting of ship strikes.

Controlled Exposure Experiments (CEE's) are part of the solution, but very controversial because they make sounds to test cetacean reactions, and no one knows when sound harms, or if sounds well below harmful levels will provide useful answers. Most scientific panels now recommend CEE's, while most organizations like CSI oppose them. The obvious solution is to enable scientists to study real-time cetacean reactions to active sonars that would be used anyway. The scientists would not make any sounds, just document. Every sonar use is a potential experiment to a qualified scientist. Everyone would benefit, especially the Navy. We have pleaded before that, while security justifiably masks locations of all military vessels, specific information could be given to cleared people to allow correlations with events, especially with advanced notice of sonar events. There is no logical need to always be responding to surprise events, especially as everything depends on a very rapid response with specific equipment and training.

CSI has to believe that solutions are possible, because the alternative is an ever-increasing war between national navies and the world, as well as whales. For the record, CSI supports the need for national security, and we understand how vital active sonars are to the military mission, but we have been ashamed to see our proud Navy hide behind national security rather than actively pursue ways to do their job without unnecessary destruction. After CSI's ten years of diving deeper into the issue it seems that it is largely Navy pride and turf that prevents proactive cooperation, not a lack of innovation or technical skill.

Finding a way for sonars and whales to coexist is only possible if the military accepts that there are more benefits from useful cooperation than from spending time and (taxpayer) money preventing solutions. They say they are good stewards of the oceans, but they don't act like it.