US Navy Sonar vs Whales and marine mammals.

[u-5075]

US court ruling on sonar could restrict Navy sub hunters
IAN BRUCE, Defence Correspondent January 05 2008


A judge has banned the US Navy from using a powerful submarine-hunting sonar within 12 miles of the coast to reduce potential harm to whales and other marine mammals, a ruling which could also affect the Royal Navy.

The California court decision is likely to trigger a new clash between Holyrood and Westminster by helping to shape a proposed marine environmental bill by the Scottish Government later this year.

The ruling, which has been eagerly awaited by environmentalists around the world, gives ammunition to wildlife campaigners seeking to limit the RN's use of the same low frequency active sonar system. The court's judgment could now be used to influence the Scottish Government's Sustainable Seas Taskforce, a group due to produce proposals by April for new marine conservation legislation.

The taskforce's remit includes recommendations on increasing Holyrood's powers over activity in the waters between 12 and 200 miles off the Scottish coast.

In Britain, the Ministry of Defence is subject to all existing wildlife legislation unless it applies for specific exemptions on the grounds of national security.

The sonar at the centre of the US court action can produce 160 decibels at a range of more than 120 miles, 50 times louder than the US Navy's safe-sound limit for human divers.

It works by sending out bursts of high-intensity sound waves that are used to hunt and track submarines by bouncing the emission off a hostile boat's hull to identify its position.

Evidence gathered since the mid-1990s connects sonar with mass strandings of whales, particularly the deep-diving beaked whale. A beaching of an entire whale pod in the Bahamas in 2000 during a US Navy sonar exercise provided the first conclusive evidence that the sounds were driving some whales ashore to their deaths.

Sonar-related strandings have also been confirmed off the Canary Islands and Spain, and other incidents have been reported off Hawaii and Washington state. Tests on the British version of the system, known as sonar 2087, have been carried out at the Butec base at Kyle of Lochalsh.

The range is a laboratory for torpedo and submarine development, covering a huge area of sea stretching from the base north through the Sound of Raasay.

The long-awaited US ruling follows more than a year of legal sparring between environmentalists and the Pentagon. Apart from creating a 12-mile no-go area for sonar emissions, it expands the navy's proposed shut-down zone for the system from 1100 to 2200 yards whenever a marine mammal is detected near warships.

It also says the military must delay the start of exercises for at least an hour while scanning passively - not sending out bursts of sonar sound but merely listening - before using an active system. Two US National Marine Fisheries Service lookouts must also be posted on warships as monitors during anti-submarine exercises.

The Royal Navy says it has developed "a range of mitigation measures to minimise the impact of sonar fitted to surface warships".

These include cutting off the 2087 sonar system when whales, dolphins and other cetaceans are detected nearby, and steering clear of areas known to be popular breeding grounds.

[woodstock74]

Correct a misconception if that's

Correct a misconception if that's the case, but I was under the impression that US sonar doctorine was biased towards passive detection. Isn't the active ping a no-no? Certainly doesn't change the need for the Navy to test a new active system, but I've been reading about this in the news for the past couple of years and was wondering if there was more to this.

[u-5075]

Recently (within the last day

Recently (within the last day or so) there have been a number of articles similar to this one below.

Navy undertakes efforts to protect sea life

By Kenneth R. Weiss, Los Angeles Times Staff Writer
January 28, 2008
http://www.latimes.com/news/local/la-me ... &cset=true
ABOARD THE USS ABRAHAM LINCOLN -- -- A sonar technician listening through his headset caught the trail of an "enemy" submarine just before a line of warships cruised through waters between Santa Catalina and San Clemente islands.

The whooshing sound of bubbles created by the submarine's propeller had been picked up by passive acoustic monitoring, made famous in the movie "The Hunt for Red October." The detection -- part of a sophisticated naval training exercise over the weekend -- popped up on green- and red-lighted screens in command centers aboard the aircraft carrier and its support ships.





If not for a recent federal court order, the accompanying destroyers would have begun to track the submarine by activating a powerful sonar that issues a loud ping and then waits for the echo to reveal the target's location.

But at times this weekend, the sonar had to be turned off. A judge, concerned about the potential harm to whales and dolphins, forbade its use in the area between the islands, waters known for their rich abundance of marine mammals. The submarine soon got away in the murky depths.

And so began the war games that will continue this week, a final exam after months of training to determine if the carrier strike group lead by the Abraham Lincoln is prepared to meet threats of all kinds -- including submarine attacks -- before it heads to the Persian Gulf in March.

"This is a game of cat and mouse," said Navy Secretary Donald C. Winter, who flew out from Washington to observe the training. "Any time we have to shut down our sonar creates huge problems for us. We want to do everything we can to protect the whales but not risk compromising our training."

These training missions in Southern California waters have become a classic case of competing interests: environmental protection versus troop readiness. The training runs have been entangled in lawsuits, federal court orders and recently a move by President Bush to override the courts -- setting up a struggle between the executive and judicial branches of government.

The 6,500 sailors on six ships in the carrier group aren't tuned in to the legal and constitutional challenges happening on shore. Each is focused on individual tasks in an elaborate choreography masterminded by Vice Admiral Samuel J. Locklear III, commander of the U.S. 3rd Fleet.

Locklear said he is working from a secret playbook that will test sailors' mettle, distract them, spread the ships thin and probe for weaknesses. "They don't know what's coming," he said.

Throughout the weekend, fighter jets catapulted off the aircraft carrier and then returned at night to make tail-hook landings on deck in stormy seas. Meanwhile, destroyers were maneuvering to sweep the horizon for hostile boats and scan beneath the waves for submarines.

As soon as the strike group moved south of the islands, the destroyers were allowed, under the terms of the court order, to turn on the midfrequency active sonar. The powerful sonar is used to hunt for the type of quiet diesel-electric submarines now operated by Iran, China, North Korea and three dozen other countries.

By midafternoon Saturday, the strike group located the submarine with the ship-based sonar. Helicopters were dispatched with a special dipping sonar that was lowered by cable into the water.

The ships tracked the enemy sub for a while, but it managed once again to elude them.

At 2 a.m. Sunday, the target submarine -- a U.S. sub playing the role of the enemy -- surfaced near the carrier and radioed to announce its location. In these games, it was a taunt that prompted a round of urgent, middle-of-the-night phone calls.

"It's very embarrassing that the submarine got in on us," said one Navy captain. "But it shows how a submarine can hide among pinnacles and seamounts, and we'll have to learn from it."

Tracking submarines, Navy officials say, is "an art steeped in science." That is to say, it isn't easy even with the powerful sonar.

One problem is that the ocean creates layers of water with different temperatures. Sonar can bounce off lower, colder layers, and clever submarine crews learn to mask their whereabouts by hovering beneath them.

Another challenge is that submarines can find hiding places in the nooks and crannies around islands and undersea mountains.

But these places also attract whales, dolphins and other marine mammals. So conservation groups and the California Coastal Commission have been pushing the Navy to be extra careful when using sonar in these areas to avoid harming marine mammals.

Although the Navy says there's no evidence that these training missions have killed marine mammals in Southern California, other naval exercises using midfrequency sonar have been linked to whale and dolphin deaths in the Bahamas, the Canary Islands and elsewhere.

On Sunday, the crew aboard the destroyer Momsen showed Winter its multilayered strategy to protect whales. The efforts included reducing the power of midfrequency sonar by 75% any time a marine mammal was spotted within 1,000 yards. Sailors trained as lookouts scanned the horizon through powerful binoculars for whales and dolphins as sonar technicians listened for the mammals.

Winter said he was impressed with how the crew responded to an imagined whale sighting. Technicians quickly turned down the sonar power and then shut it off when the whale ventured within 200 yards.

U.S. District Judge Florence-Marie Cooper last year saw a similar Navy drill, although the destroyer remained in port in San Diego. After watching the demonstration, reviewing the scientific literature and the Navy's own environment assessment, she called the Navy's efforts "grossly inadequate to protect marine mammals from debilitating levels of sonar exposure."

On Jan. 3, the Los Angeles-based judge issued a court order that increased the Navy's surveillance for whales.

She ordered commanders to refrain from using powerful sonar within 12 nautical miles of the coast and in the waters between Santa Catalina and San Clemente islands.

She wanted the Navy to expand its safely zone for shutting down sonar and reducing sonar power under certain sea conditions.

Navy officials say the added restrictions greatly reduce its ability to train in realistic conditions.

They say the waters between Catalina and San Clemente islands present the same challenges as in the Persian Gulf's Strait of Hormuz, for instance.

Cooper is expected to rule as early as this week on the Navy's request that she lift all the restrictions, arguing that the issue is moot because President Bush exempted these exercises from the laws that formed the basis of the lawsuits.

California officials and conservation groups rebut this legal argument and have urged Cooper to uphold the ruling.

[hakkikt]

For anyone interested in the

For anyone interested in the effects of low frequency sonar on marine animals, I found this after a quick search:

http://www.oceanmammalinst.org/mgpaper.html

I understand that we are talking medium frequency sonar here, so the effects might not be directly comparable.
Anyway, I was especially impressed by this (found in the above article):
"On August 25, 1994 a scuba diver was accidentally exposed to testing of the US Navy's LFA sonar system. (Comments submitted at Public Hearing of California Coastal Commission, 12/12/97). The ship transmitting the sonar was over 100 miles northwest of the diver who reported distinct and disorienting lung vibration as a result. Pestorius and Curley (1996) exposed Navy divers to low frequency active sonar and reported that one of the divers had to be hospitalized and was later under treatment for seizures."