sail-world.com
 
 
News Home Cruising Photo Gallery Video Gallery

 

Sail-World.com : WHOI-Led Report Links Sonar to Whale Strandings

WHOI-Led Report Links Sonar to Whale Strandings

'Scientists know so little about beaked whales like this adult because they prefer deep waters far offshore, where they can dive on one breath of air to depths of over a mile for up to an hour and a half, according to WHOI’s Tyack. (Photo by Todd Pusser, taken under NMS permit 14241)'    Woods Hole Oceanographic Institution (WHOI) ©

Scientists have long been aware of a link between naval sonar exercises and unusual mass strandings of beaked whales.

Evidence of such a link triggered a series of lawsuits in which environmental groups sued the U.S. Navy to limit sonar exercises to reduce risk to whales. In 2008, this conflict rose to the level of the US Supreme Court which had to balance potential threat to whales from sonar against the military risk posed by naval forces inadequately trained to use sonar to detect enemy submarines. The court ruled that the Navy could continue training, but that it was essential for the Navy to develop better methods to protect the whales.

The knowledge most critical to protecting these whales from risk of sonar involves measuring the threshold between safe and risky exposure levels, but until now it has not been known how beaked whales respond to sonar, much less the levels that pose a problem. 'We know so little about beaked whales because they prefer deep waters far offshore, where they can dive on one breath of air to depths of over a mile for up to an hour and a half,' said Peter Tyack, a senior scientist at Woods Hole Oceanographic Institution (WHOI).

Now, an international team of researchers reports in a paper led by Tyack the first data on how beaked whales respond to naval sonar exercises. Their results suggest that sonar indeed affects the behavior and movement of whales.

Tyack and his colleagues used two complementary methods to investigate behavioral responses of beaked whales to sonar: 'an opportunistic approach that monitored whale responses to multi-day naval exercises involving tactical mid-frequency sonars, and an experimental approach using playbacks of simulated sonar and control sounds to whales tagged with a device that records sound, movement, and orientation,' the researchers report in the current issue of the journal PLOS (Public Library of Science) ONE

That research team developed experiments to slowly increase the level of sonar at a tagged whale, to stop exposure as soon as the whale started responding, to measure that exposure, and to define the response. The experimental approach used tags to measure acoustic exposure and behavioral reactions of beaked whales to one controlled exposure each of simulated military sonar, killer whale calls, and band-limited noise.

'These experiments were very difficult to develop, and it was a major breakthrough simply to be able to develop a study that could safely study these responses,' Tyack said. 'All three times that tagged beaked whales were exposed experimentally to playback of sounds when they were foraging at depth, they stopped foraging prematurely and made unusually long and slow ascents to the surface, moving away from the sound.

WHOI’s Peter Tyack and other scientists kept track of some of the beaked whales like this by means of a Dtag. The novel archival tag has been developed to monitor the behavior of marine mammals, and their response to sound, continuously throughout the dive cycle. The tag contains a large array of solid-state memory and records continuously from a built-in hydrophone and suite of sensors. (Photo by Todd Pusser, taken under NMFS permit 14241) -  Woods Hole Oceanographic?nid=81770 Institution (WHOI) ©  

Beaked whales use their own biosonar to find prey when they are foraging; this means that one can monitor cessation of foraging by listening for when they stop clicking. Once the researchers found that beaked whales responded to sonar by ceasing clicking, they were able to monitor reactions of beaked whales during actual sonar exercises on the range. The research was conducted on a naval testing range where an array of underwater microphones, or hydrophones, covered the seafloor, allowing whale sounds to be monitored over 600 square miles. 'During actual sonar exercises, beaked whales were primarily detected near the periphery of the range, on average 16 km away from the sonar transmissions. Once the exercise stopped, beaked whales gradually filled in the center of the range over 2-3 days,' they report.

A satellite tagged whale moved outside the range during an exercise, returning over 2-3 days post-exercise. 'The combined results indicate similar disruption of foraging behavior and avoidance by beaked whales in the two different contexts, at exposures well below those used by regulators to define disturbance,' the scientists report.

'This suggests that beaked whales are particularly sensitive to sound. Their behavior tended to be disrupted at exposure levels around 140 decibels (dB), so they may require a lower threshold than many current regulations that anticipate disruption of behavior around 160 dB, ' said Tyack. 'But the observations on the naval range suggest that while sonar can disrupt the behavior of the whales, appropriate monitoring and management can reduce the risk of stranding.'

The research was supported by the United States Office of Naval Research, the U.S. Strategic Environmental Research and Development, the Environmental Readiness Division of the U.S. Navy, the U.S. Chief of Naval Operations Submarine Warfare Division (Undersea Surveillance), NOAA and the Joint Industry Program on Sound and Marine Life of the International Association of Oil and Gas Producers. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

The Woods Hole Oceanographic Institution is a private, independent organization in Falmouth, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment.

http://www.whoi.edu/




by Woods Hole Oceanographic Institution

  

Click on the FB Like link to post this story to your FB wall

http://www.sail-world.com/index.cfm?nid=81770

12:42 PM Sun 27 Mar 2011 GMT






Click here for printer friendly version
Click here to send us feedback or comments about this story.


News - USA and the World



















The first annual WetaFresh is a big success by Tim Wieringa, Muskegon, MI


















Techno 293 Worlds - France and Italy claim titles by International Windsurfing Association,














420 World Championship - Singapore and Spain out front by 420 International Class Association,
















Round Britain and Ireland Race 2014 - Tactics, endurance, achievement
Alpari World Match Racing Tour moves on to Poland + Video
2014 ISAF Sailing World Cup final qualification system published
Chicago Yacht Club Race to Mackinac - Karma Sailing Group wins
Red Bull 49erFX: Easing into the Olympic scene at Rio
Kempe thrilled to invite himself to Gold Cup party
2014 420 World Championships - Singapore wins Day 2 race
Lightning strikes cut short CFJ Nationals
Etchells Invitational Cup - Girls on top in Cowes
National Sailing Hall of Fame reveals inductees
J/111 North American Championship - Wind Czar victorious
Sevenstar Round Britain and Ireland Race sets off August 10th
PWA Fuerteventura Grand Slam - Antoine Albeau victorious on day 5
Snipe Western Hemisphere and Orient Championship headed for San Diego
WPA Championships - Kids race divisions offered
New Clever Pig launched by US Sailing
America's Cup: Group agrees to co-operate in London Meeting
Copa del Rey Mapfre - Build-up reveals some remarkable enthusiasm
Marblehead NOOD Regatta - Images by Leighton O'Connor
America's Cup: Two AC72 skippers discuss Foiling Moths and the Cup
RS Feva World Championship - Brilliant sailing on day 2   
America's Cup: Alameda makes overtures on Venue hosting for San Fran *Feature   
Cape Panwa Hotel Phuket Race Week 2014 - Relishing a challenge   
Edgartown Race Weekend - BBBR and Round-the-Island Race winners named   
Etchells Invitational Cup - Aussies take early lead in Cowes   
PWA Fuerteventura Grand Slam - Antoine Albeau strikes back on day 4   
Aquece Rio – International Sailing Regatta - All set for test event   
ISAF World Sailing Rankings for 28 July 2014   
29er World Championship - All set in Kingston   
ORC World Championship - Third Course area opens for huge fleet   
Day one of the Allen RS Feva World Championships   
Anna Tunnicliffe: Final two days of the 2014 Reebok CrossFit Games   
Joachim Aschenbrenner takes gold at ISAF Youth Match Race Worlds 2014   
Maxi Soh scores double wins in CMRC Summer Doubleheader   
29er World Championship opening ceremonies in Confederation Park   
PWA Fuerteventura Grand Slam - Action resumes on day 3   
Vic-Maui Yacht Race - Polishing the silverware   
Land Rover Sydney Gold Coast Yacht Race Start 2014 VIDEO   
Laser Radial Men’s World Championship 2014- Final day   
2014 Pacific Cup - Scarlet Runner wins   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png http://www.sail-world.com/event_images/image/FaceBook-icon.png  http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW US
LocalAds   DE  ES  FR  IT