Hermanus in the heart of the Cape Whale Coast of South AfricaContact Us

Naval Sonar Is Killing And Beaching Whales

  • Monday, 18 February 2019
  • Linda Chivell

beached whales
We have known for a long time that naval sonar has devastating effects on marine life but just exactly how it leads to sickness and death was a mystery till now. 

The sound emitted by sonar is so intense that marine mammals will swim hundreds of miles, dive deep into the abyss or even beach themselves to flee from the sounds that are literally unbearable to them, according to new research published in the Proceedings of the Royal Society B,

Beaked whales, in particular, are one of the marine mammals that are often found beached due to sonar testing. Prior to the 1960s, beaked whale strandings were extremely rare, that was until the Navy started to use mid-frequency active sonar (MFAS) to detect submarines.
More and more frequently, whales started washing up on beaches after the 1960s

In a paper that was recently published whale experts revealed that sonar distresses beaked whales so much that the marine mammals end up with nitrogen bubbles in their blood very similar to what divers would call decompression sickness or the bends.

And if that is not horrific enough, the nitrogen caused haemorrhaging and damage to whales vital organs.

Asking the big question was how an animal that lives in the ocean and is adapted to perform deep water dives for hours at a time can obtain decompression sickness? In laymen’s terms; the sonar is so powerful that the animals dive deep too quickly causing the sickness.
“In the presence of sonar, they are stressed and swim vigorously away from the sound source, changing their diving pattern,” according to the lead author Yara Bernaldo de Quiros

“The stress response, in other words, overrides the diving response, which makes the animals accumulate nitrogen. It’s like an adrenalin shot.”

The conclusions are drawn from autopsies of dead whales, although a handful of animals were killed by other threats inflicted by humans, such as collisions with ships or entanglement in fishing nets, as well as disease.

The scientists suggested that to mitigate the impacts of sonar on beaked whales, sonar must be banned in areas frequented by beaked whales. The moratorium on the use of MFAS around the Canary Islands in 2004 is proof of just how well this works – no atypical strandings have been seen since.

The researchers implored other countries such as the US, Greece, Italy, and Japan, where sonar is deployed, to follow suit.



Article originally appeared in the Sea Voice News

Call us and schedule your listing today! Contact Us

whale watching hermanus


in and around Hermanus

With countless Southern Right Whales gathering along the Whale coast every year to mate and to calve



Shark Cage Diving

One for the Bucket list

Experience the exceptional and come face to face with a great white shark! Gansbaai also known as Shark Alley…

Learn More

hermanus wine tasting


4 x Wine Routes

Hermanus is surrounded by 4 Wine routes, the Hermanus - (Hemel-and-Aarde); Stanford -, Elim - and Botriver Wine Route



Top Activities

in the Cape whale Coast

Hermanus is a spectacular seaside town with winding cliff paths, sloping green mountains, and deep blue waters.

Learn More

Office Locations

Hermanus Office

25 Mitchell Street, Checkers Building, Hermanus, South Africa
Phone: +27 (0) 28 312 3846

Online Marketing Team

Jaydee Media
Phone: +27 (0) 28 312 3846