Bats vs. Dolphins: Ultimate battle of sonar systems

Date:  November 6, 2018

Source:  Acoustical Society of America

Active sensors are incorporated into a number of technologies, such as meteorology devices and self-driving cars, and use the echo from sound, radio or light waves to locate objects. But despite nearly a century of development, these active sensing technologies still fail to replicate the performance of sonars (sound waves) used in the biological world by dolphins and bats for echolocation.

To find ways to improve human-made active sensing, scientists worldwide study the sonar systems of bats and dolphins. During the Acoustical Society of America's 176th Meeting, held in conjunction with the Canadian Acoustical Association's 2018 Acoustics Week, Nov. 5-9, at the Victoria Conference Centre in Victoria, Canada, Laura Kloepper, assistant professor at Saint Mary's College in Notre Dame, Indiana, will compare bat and dolphin sonar systems, describing her work on how the two animals cope with acoustic interference. She'll use her findings to argue why bats have the superior system.

"I'm on Team Bat," said Kloepper. "But I'm going to be presenting dolphin work to argue why bats are better." She hopes her talk sparks a healthy debate between researchers of both animals.

Kloepper's talk is part of a special session devoted to bat and dolphin sonar systems. Several of the speakers in the session will appear in a press conference devoted to the subject.

Overcoming Interference, Bat and Dolphin Style

Continued  

US Navy banned from using sonar that harms dolphins and walruses

Low-frequency sonar used for training and testing can injure whales and other marine life, and disrupt their feeding and mating

Associated Press

Saturday 16 July 201605.57 BST

A federal appeals court ruled on Friday that the US Navy was wrongly allowed to use sonar in the nation’s oceans that could harm whales and other marine life.

The ninth circuit court of appeals reversed a lower court decision upholding approval granted in 2012 for the Navy to use low-frequency sonar for training, testing and routine operations.

The five-year approval covered peacetime operations in the Pacific, Atlantic and Indian Oceans and the Mediterranean Sea.

The appellate panel sent the matter back to the lower court for further proceedings.

A message seeking comment from representatives of the US Pacific Fleet in Honolulu was not immediately returned.

Sonar, used to detect submarines, can injure whales, seals, dolphins and walruses and disrupt their feeding and mating.

The 2012 rules adopted by the National Marine Fisheries Service permitted Navy sonar use to affect about 30 whales and two dozen pinnipeds; marine mammals with front and rear flippers such as seals and sea lions, each year.

The Navy was required to shut down or delay sonar use if a marine mammal was detected near the ship. Loud sonar pulses also were banned near coastlines and in certain protected waters.

Continued ...

Navy sonar 'most probably' to blame for mass dolphin stranding

The largest mass stranding of dolphins in the UK has been blamed on sonar from navy exercises, "most probably". 

Royal Navy exercises have been cited as the “most probable” cause for the mass stranding of 26 dolphins found dead or dying in and around the Percuil River at St Mawes almost five years ago, according to a report released by scientists. 

The study has been called a 'game changer' by charity Whale and Dolphin Conservation who said it was compelling that all other causes of death were ruled out. 

On June 9, 2008, the UK’s largest mass stranding event (MSE) of common dolphins occurred in Falmouth Bay when at least 26 animals died and a similar number were refloated or herded back to sea. 

Continued: http://www.falmouthpacket.co.uk/news/fpfalmouth/10404271.Sonar__most_probably__to_blame_for_mass_dolphin_stranding_in_2008/

Nessie 'sighting' wins £1000 prize

A SONAR image of a large mystery object deep below the surface of Loch Ness has netted boat skipper Marcus Atkinson the Best Nessie Sighting of The Year Award — the first time in several years it has been presented by bookmaker William Hill.

The photograph, claimed by at least one seasoned Nessie spotter to the conclusive evidence of a creature, was a late contender in the contest which has been dormant following several lean years of close encounters with the loch’s most famous resident.

However, 2011 proved to be a bumper year with three “good” sightings reported to the Official Loch Ness Monster Fan Club which first launched the competition in conjunction with the bookmaker in the 1990s.

Although Mr Atkinson’s encounter in Urquhart Bay was not registered at the time with the fan club, it was reported to full-time Nessie hunter Steve Feltham, based at Dores beach. The image depicts something about 1.5 metres wide and 23 metres below the surface. 

The entry has now been judged to be the winner by Inverness Courier readers in an online poll along with the views of an expert panel.

Mr Atkinson receives a £1000 cash prize and a free £500 bet while William Hill will also place a £100 bet on the Natural History Museum confirming the existence of Nessie by the end of the year — odds are currently 100/1.

“I am absolutely delighted. It’s fantastic especially as the competition has been revived,” said Mr Atkinson who captured the image on 24th August while on his boat, Ness Express, waiting to pick some customers up from Urquhart Castle.

The quick-thinking skipper grabbed his mobile phone after a long solid echo appeared on the boat’s fish finder screen.

Mr Atkinson, who has spent about 18 years working on the loch, both on pleasure boats and teaching people to sail, remains baffled by the image.

“I think for a lot of ‘sightings’, there is often a logical explanation,” said the 43-year-old who believes some are seals, or stags swimming in the loch.

“Some sightings could have been a freak wave which people have caught in the periphery of their vision, or a dark shape.

“But I have never seen anything returned like this on the fish finder.

“It is a bizarre shape to me. I have shown it to other experienced skippers and none of us know what it was.

“Undoubtedly, there is something in the loch. I think there is truth behind every myth.”

Gary Campbell, president of the Official Loch Ness Monster Fan Club, described the image as quite exciting.

“From our perspective, it is conclusive proof there is something in the loch unlike some of the other ‘evidence’ which has been produced over the years,” he said.  

Rupert Adams, of William Hill, paid tribute to the winning image.

“Having something which is more specific in showing an object is very exciting for people who have an open mind to the existence of a Loch Ness monster,” he said.

Mr Adams also hopes it will encourage Nessie spotters to take part in an even “bigger and better” competition, the details of which will be announced soon. 

Other entries were:

* Runner-up Lewiston fish farm worker Jon Rowe who photographed a large, dark shape in the water while working at Dores fish farm. 

* Ayshire holidaymakers William and Joan Jobes who spotted what appeared to be a head bobbing above the water 200 to 300 yards from the shore at Fort Augustus.

* Foyers shop and cafe owner Jan Hargreaves and her husband, Simon, who saw a creature while taking a break from the store.

*Gary Campbell’s verdict on the sonar image which shows something about 1.5 metres wide and 23 metres below his boat:

“This is as good as any sonar image found in the loch. The important thing is that someone else went over the same patch and what was there, had gone.

“When you look at the size of the contact, it rules out any fish or other creatures which would be in the loch. Because of the depth, it rules out seals, deer etc which leaves us with only one conclusion.

“From our perspective, it is conclusive proof there is something in the loch unlike some of the other ‘evidence’ which has been produced over the years.

“This shows something moving and also by the nature of the sonar, it was certainly something alive underneath the boat. It is quite exciting.”  

http://www.inverness-courier.co.uk/News/Nessie-sighting-wins-1000-prize-13022012.htm