The Navy is planning extensive training in the Pacific Northwest. Here's how that might affect marine animals.
By EVAN BUSH | The Seattle Times | Published: May 25, 2019
SEATTLE, Wash. (Tribune News Service) — The Navy’s latest testing and training proposal in the Northwest reveals the secretive military branch’s futuristic technology and planned war-game maneuvers. It also outlines how Navy sonar and explosives could harm marine animals.
The nearly 1,800-page document, two volumes of Navy bureaucratese, details proposals to test the Navy’s rail-gun system (it can fire projectiles at up to seven times the speed of sound), pilot mine-detecting underwater drones and fly its airborne surveillance drone at 50,000 feet.
But in recent years, scientists’ understanding of how sound can harm, and even kill, has grown.
And the Navy’s models, which estimate temporary and permanent hearing loss for thousands of marine creatures in the Northwest, are under scrutiny.
The Navy’s proposal here could tee up the latest battle over sonar — essential to national security at sea, but also a threat to the creatures trying to make an increasingly noisy ocean home.
Navy’s Northwest plans
The environmental impact documents outline the Navy’s preferred plan for testing and training beginning next year in Puget Sound, coastal waters from northern California through Washington state, and for Alaska.
The Navy plans air combat maneuvers, submarine tracking and detection exercises, electronic warfare practice, mine training, torpedo testing and more, according to the documents.
Noisy, controversial Growler jets would fly slightly more often, but the Navy’s preferred proposal doesn’t represent a major shift in overall activity.
The documents form the backbone of the Navy’s application to the National Marine Fisheries Service (NMFS) for permits to do incidental harm to marine mammals. The NMFS, a division of the National Oceanic and Atmospheric Administration, regulates the Navy’s impacts on marine life under the Marine Mammal Protection Act and Endangered Species Act.
To explain those impacts, the Navy relies on a complex modeling program that consider species range, density, sensitivity to sound and other factors, said John Mosher, the Navy’s U.S. Pacific Fleet Northwest Environmental Program Manager.
The documents outline the risks of military sonar.
Many marine animals rely on sound to communicate, locate food, avoid predators and navigate. Exposure to sound could change their behavior, said John Calambokidis, a research biologist and founder of Cascadia Research Collective.
Intense or repeated exposure to certain frequencies of sonar could also affect animals’ ability to hear sounds in those ranges, he said.
“For marine mammals that utilize sound extensively, limiting their ability to recognize these frequencies in sound is going to limit their survival,” Calambokidis said.
Over seven years, harbor porpoises in inland Washington waters could experience temporary hearing loss at some frequencies at least 95,943 times from sonar, according to the Navy’s calculations.
Sonar would cause those porpoises permanent hearing loss 1,033 times and a “behavioral reaction” — anything from a distraction to prolonged fleeing from sound — 101,377 times, according to the estimate.
“It may be something that distracts the animal from normal activities, such as feeding or reproduction,” Mosher said.
Many of these animals could be exposed to sonar multiple times. A 2016 study published in the Canadian Journal of Zoology estimated that 11,233 harbor porpoises live in inland Puget Sound waters.
Dozens of other creatures in the Salish Sea would be affected in lesser numbers, including endangered southern resident killer whales, which the Navy predicts would exhibit behavioral responses about 15 times over seven years. The documents say endangered humpback whales in waters off California, Oregon and Washington would suffer temporary hearing loss 277 times and alter their behavior 221 times because of sonar.
Mosher said the models are conservative estimates.
“We model for the worst case possible,” he said.
For example, the modeling program assumes sonar systems are at full power, which is not always the case, he said.
The Navy also plans for more training than it typically needs, Mosher said.
“We, almost across the board, do not execute to the levels we permit for,” Mosher said, to “allow for changing world events.”
The Navy is required by NMFS to produce annual reports describing testing and training, but much of the information is classified. The Navy did not disclose sonar-use figures in recent public reports, but said it did not exceed permit levels.
A review of the annual reports from November 2015 through November 2018 shows the Navy detonated a tiny fraction of the amount of explosives for which it was permitted.
Navy’s sonar history
As submarine technology improved after World War II, the Navy began to develop active sonar, which produces intense, intermittent sound to track submarines.
As submarines have grown more quiet, sonar technology has had to adjust.
“In the last 20 years, the diesel-powered subs of U.S. adversaries, they’ve gotten so quiet, the Navies are … having to project and use sonar detection over longer ranges.” said Brandon Southall, a scientist and consultant who helped develop NMFS’ acoustic exposure criteria for marine animals.
That requires lower frequency sound waves that travel farther.
Concerns about naval sonar date back decades.
The Navy first acknowledged sonar’s damaging effects in 2001, after 16 whales stranded — or beached — in the Bahamas in a day and a half’s time the year prior. Six animals died; the others were pushed off or escorted to deep water, according to a report from NMFS and the Navy.
Several received necropsies. Two animals — the freshest of the dead whales — had hemorrhaging and blood in their inner ears and around their brains consistent with “acoustic or impulse injuries” which likely triggered the strandings, according to the report. The use of midfrequency sonar by Navy vessels near an underwater canyon was likely to blame, the investigation concluded.
In 2003, a Navy ship used sonar during training in the Haro Strait, between Victoria, B.C., and the San Juan Islands. Biologists reported abnormal behavior by nearby killer whales. Sixteen porpoises stranded soon after the ship passed.
Investigations found that the killer whales likely heard the sonar and that it was loud enough to send them fleeing, but did not conclusively link sonar to the stranded porpoises.
Environmental groups have been wrangling with the Navy and NMFS in court.
The U.S. Supreme Court in 2008 ruled that the Navy could continue to use high-powered sonar off California’s coast even if it harmed marine mammals, emphasizing in its majority opinion the military threat of near-silent submarines.
Four years later, conservation groups and American Indian tribes filed a lawsuit over a 2010 plan involving sonar in the Northwest. A federal-district court judge required the Navy and NMFS to rework some analysis and consider new science.
In 2015, after a judge sided with environmental groups, conservationists reached a settlement with the Navy making whale habitat in Hawaii and Southern California off-limits to sonar.
The next year, a federal appeals court ruled that the Navy should not have been allowed to use low-frequency, long-range sonar in some locations, concluding it had not given “adequate protection to areas of the world’s oceans flagged by its own experts as biologically important …”
Environmental groups have been poring over the Navy’s newest plan here.
“We still remain quite worried about effects on a number of populations,” said Michael Jasny, of the Natural Resources Defense Council, the organization leading much of the litigation.
Following high-profile mass strandings, scientists’ understanding of marine creatures’ sensitivity to sound has improved. The science, some of it funded by the Navy itself, has rapidly progressed over the last decade, Calambokidis said.
“Now, the evidence is so overwhelming, there’s no one who really questions those stranding events were linked to the Navy sonar,” he said, referring to multiple mass strandings of beaked whales.
Hearing ability differs among marine mammal species.
Southall said researchers have measured some species’ sensitivity by performing laboratory testing on captive animals. He compared the tests to hearing screeners, in which young children raise their hands when they hear certain tones. Similarly, the scientists measure when creatures acknowledge certain frequencies of sound.
New technology has aided field research. Calambokidis now uses high-tech tags, attached “to the whales with suction cups” that feature sensors like 3D-accelerometers, gyroscopes, depth sensors and hydrophones.
Hydrophones measure “exactly what level of sound” whales are exposed to while other sensors capture reaction data. The tags can remain on whales’ bodies for hours or even days.
Reactions vary. Deep-diving beaked whales are particularly sensitive to sonar, Calambokidis said. In one study, tagged Cuvier’s beaked whales were shown to “respond very dramatically” when a recording of naval sonar was played, he said. Whales swam quickly away from the sound source, extended dives deeper and stopped food foraging.
In a similar study, blue and fin whales avoided the sound and stopped feeding, Calambokidis said, but their reactions were less dramatic and more variable.
Navy mitigates, but concerns persist
The Navy tries to avoid marine mammals when firing weapons, testing torpedoes or using active sonar.
Before using active sonar, sailors listen for whales with passive sonar equipment, Mosher said. On-deck lookouts are trained to spot marine creatures before explosives or sonar are deployed. If a marine animal is spotted within ranges that could cause harm, sonar systems must be powered down, he said.
The service is required to report to NMFS all ship strikes or instances when a marine mammal is killed or injured after Navy exercises. During a Navy operation in 2016, a Coast Guard vessel struck a humpback whale, but there have not been other incidents to report, Mosher said.
The new Navy models don’t predict any marine mammal deaths from sonar or explosives. Jasny contends that “begs credulity.”
“Some of the most vulnerable species, like beaked whales, are nearly impossible for trained observers, trained biologists, to detect,” he said, noting that high-intensity sonar travels farther than lookouts can see. The Navy does not explicitly restrict its activities during low-visibility sea conditions or at night, he said. (Mosher said the Navy requires clear visibility for weapons training and rarely uses sonar after dark).
Jasny added it’s “just not sustainable” that nearly one of 10 inland Washington harbor porpoises would suffer permanent hearing loss, according to the Navy’s own seven-year estimates.
He also questioned the Navy’s proposed handling of southern resident killer whales, a population scientists say is nearing collapse.
Mosher said the service’s environmental managers track the southern residents to ensure sonar is not used in their vicinity, as it was in 2003.
Jasny called for an outright ban on sonar when the southern residents are in the Salish Sea, saying they “can’t stand any more disturbance.”