Friday, September 27, 2013


OCT 8, 2013

WASHINGTON – The mysterious stranding of about 100 melon-headed whales in a shallow Madagascar lagoon in 2008 set off a rapid international response — a few of the 3-4-meter-long marine mammals were rescued, necropsies conducted, a review panel formed.

Did they follow prey into the lagoon? Were they sick? Was it the weather, or chemical toxins?

The panel recently gave its best answer, and it is causing ripples of concern. For the first time, a rigorous scientific investigation has associated a mass whale stranding with a kind of sonar that is widely used to map the ocean floor, a finding that has set off alarms among energy companies and others who say the technology is critical to safe navigation of the planet’s waters.

The independent review panel appointed by the International Whaling Commission concluded Sept. 25 that a high-powered, “multibeam echosounder system” (MBES) was “the most plausible and likely behavioral trigger” for the stranding. About 75 of the animals, which normally inhabit deep ocean waters, died.

A contractor for Exxon Mobil was using the sonar system — which sends “ping” sounds from a vessel toward the ocean floor — in a channel between Mozambique and Madagascar to determine where an oil and gas exploration rig might be safely constructed. Computers use the returning echo from the pulses of sound to map the ocean floor.

The panel of five scientists “systematically excluded or deemed highly unlikely” nearly every other possibility before settling on the use of the MBES, which previously was considered relatively benign, according to the group’s report.

“The evidence seems clear to us that (the MBES) was pretty likely” the cause, said Brandon Southall, the panel’s chairman and a marine biologist at the University of California at Santa Cruz. He said he hopes the report will cause governments, regulatory agencies and private companies to “realize that some of the types of mapping sonars have the potential to cause reactions in marine mammals that can be detrimental.”

Exxon Mobil, which helped select the panel and partly funded the rescue of some of the whales in 2008, rejects the conclusion, contending that the evidence is too flimsy for a determination that could have a far-reaching impact.

“While Exxon Mobil is not accepting responsibility for the stranding in light of the uncertainties in the report, we did cooperate and provide funding for the response effort in 2008 and the review panel because we are working in Madagascar,” spokesman Patrick McGinn said.

Another skeptic is Larry Mayer, a professor at the University of New Hampshire’s Center for Coastal and Ocean Mapping. “From my reading of that report, it’s not clear how they could have come to that conclusion,” Mayer said. “Any of the other possible conclusions are just as likely.”

The report could have significant consequences for U.S. agencies and others around the world that use the MBES to map ocean floors. “If it endangers the ability to use these sort of systems . . . it could lead to all kinds of dangerous downstream consequences.” Mayer said.

And Joseph Geraci, an adjunct professor of comparative medicine at the University of Maryland who has studied cetacean strandings for 40 years, said he was troubled by the strength of the language in the panel report. “I’m not sure on the basis of a single event where there are two activities that the words ‘most plausible cause’ are the right ones,” he said. “It’s only those three words that made me pay attention.”

But Howard Rosenbaum, director of the Ocean Giants program of the New York-based Wildlife Conservation Society, hailed the panel for pushing the envelope on possible factors in the strandings and deaths of marine mammals. “I think what we would like to see is the most effective regulations that will minimize the risk (of mass strandings) to sensitive whales and dolphins,” Rosenbaum said.

U.S. Navy sonar has been implicated in harm to whales and dolphins, environmental groups contend. A federal judge last month ordered federal biologists to reconsider permits that could allow the navy to kill or disrupt marine mammals during antisubmarine warfare exercises off the coast of the Pacific Northwest. But in 2008, the Supreme Court allowed similar drills off Southern California to be held without protections for marine mammals.

Other environmental groups are skirmishing with energy companies over the use of “seismic air guns,” devices that send much louder blasts of compressed air toward the ocean floor to help find oil and gas trapped below.

The noise from an MBES is better compared to an industrial-sized version of the fish-finders widely used by recreational anglers, Southall said. That is part of the reason his panel’s finding is so controversial: the pinging sound is used so widely around the globe, in so many forms, that most involved have considered it relatively harmless.

But it may be time to adjust that thinking, Southall said. He said no study of whale strandings will achieve the kind of certainty that Exxon Mobil and others would like, but said this one provided a rare opportunity to consider a wide range of possibilities and disprove them.

Because the Wildlife Conservation Society has a presence in Madagascar, it was able to quickly respond to the stranding, rescuing some of the whales and conducting necropsies on the dead, Rosenbaum said.

And because regulators, conservation groups and energy companies were together at a conference in Chile at the time, they were able to put together a coordinated rescue response and later work together to form the review panel.

“It seemed to be a very uncommon event,” Southall said, “and we were able to go through almost all the factors that we looked at and rule almost everything else out.”

Exxon Mobil contends, among its other objections, that the stranding began before its contract vessel arrived off the shores of northwestern Madagascar. The company has provided satellite photographs of objects on other nearby beaches before the melon-headed whales fled into Loza Lagoon, but the panel concluded they most likely were small fishing boats.

Nevertheless, Exxon Mobile already has changed its practices to prohibit the use of an MBES near an underwater cliff face, because the panel raised the possibility that the sound pulses echoed off one in this case and had an unusual effect on the whales, McGinn said.

Southall said the whales already were in unusually shallow water for unknown reasons.

The bottom line for the company, McGinn said, is that “our contract vessel happened to be there in that time frame, but there are so many uncertainties in the area that we’re not sure it’s us.”



An independent scientific review 
panel found sonar was responsible 
for the mass stranding 
of 100 melon-headed whales 
in Madagascar

The panel concluded that a multi-beam echosounder system, used by a nearby survey vessel was the most 'plausible and likely behavioural trigger'
The report said the potential for mortality from the use of sonar systems should be considered in future environmental assessments

PUBLISHED: 06:59 EST, 27 September 2013 | UPDATED: 07:01 EST, 27 September 2013

Environmental campaigns have maintained for years that sonar systems used by shipping leads to the stranding of whales.
But now international research has confirmed their concerns for the first time that whales strand themselves on beaches when they are lost and disorientated by high-frequency underwater noise.
An independent scientific review panel found the systems, mainly used for underwater mapping, were responsible for the mass stranding of 100 melon-headed whales in Madagascar in 2008.
Sonar systems, mainly used for underwater mapping, were responsible for the mass stranding of 100 melon-headed whales
An independent scientific review panel found that sonar systems, mainly used for underwater mapping, were responsible for the mass stranding of 100 melon-headed whales in Madagascar in 2008

A report commissioned by the panel said: 'The potential for behavioural responses and indirect injury or mortality from the use of similar MBES [multi-beam echosounder systems] should be considered in future environmental assessments, operational planning and regulatory decisions.'
The noise from the high-frequency sonar systems, used by the military, shipping and research vessels, can cause the animals to swim into the wrong areas, and it is thought that use of the system leads to beachings in the UK too.

Every year 800 whales, dolphins and porpoises are stranded on British beaches, although it is not known whether sonar systems are to blame. Here, British Divers Marine Life Rescue volunteers inspect a with a 44ft Sperm whale, which died on Redcar beach in Cleveland in 2011

Every year 800 whales, dolphins and porpoises to be stranded on British beaches, although it is not known whether sonar systems are to blame.
Dr Howard Rosenbaum, director of the Ocean Giants Program for WCS, welcomed the report and said: 'These conclusions add to a mounting body of evidence of the potential impacts of anthropogenic noise on marine mammals. 
'Implications go well beyond industry, as these sonar systems are widely used aboard military and research vessels for generating more precise bathymetry (underwater mapping).

'We now hope that these results will be used by industry, regulatory authorities and others to minimise risks and to better protect marine life, especially marine mammal species that are particularly sensitive to increasing ocean noise from human activities.'

The noise from the high-frequency sonar systems, used by the military, shipping and research vessels, (pictured is the sound room of HMS Westminster in Portsmouth) can cause whales to swim into the wrong areas, and it is thought that use of the system leads to beachings in the UK too

Katie Moore, director of animal rescue at IFAW said: 'Mass stranding response is challenging under the best of circumstances.
'Together with local individuals and the government of Madagascar, we provided the expertise to rescue as many animals as possible and medical care to those that stranded alive. 
'Equally important was to gather as much data as possible from the animals to address the root cause of the stranding. We are pleased to see the ISRP report and its conclusions, which will hopefully be used in shaping future conservation policies.'

Read more: 


A recent study by the Cascadia Research Collective based in Washington, said underwater military sonar could be killing blue whales.
The reserachers said  that baleen whale species, which include the world’s largest animal, the blue whale, react to the mid frequency noises by changing behaviour.
This includes altering foraging so they miss out on high-quality prey, which could make them weak and decimate numbers through starvation.
The soundwaves, developed by the military to track enemies beneath the waves, are between 1 and 10 kHz, which is within the human hearing band.
They have been blamed for lethal mass stranding of deep diving toothed whales.
Sonar is thought to disrupt the animals’ diving behaviour so much  that they suffer a condition rather like ‘the bends’ which human divers can contract if they surface too quickly.

This research claims that sonar can significantly disrupt their foraging and dramatically decrease feeding efficiency as undersea noise blocks animals’ communication.
Teams from the Wildlife Conservation Society (WCS) and International Fund for Animal Welfare (IFAW) were able to rescue some of the whales, but it was too late for many of them. 
While aspects of the stranding in Madagascar remain unknown, the panel concluded that a multi-beam echosounder system, operated intermittently by a survey vessel moving down the shelf-break the day before the event was the most 'plausible and likely behavioral trigger for the animals initially entering the lagoon system.'
There are now concerns about the impact of noise on marine mammals as the systems are commonly used by many industries. 

No comments:

Post a Comment