14 DAY TRIAL // The fact that dolphins and whales don't enjoy having their peace disturbed by boats, submarines and whatnot has long been known to wildlife researchers.
A new study documents how these animals respond to unnatural underwater noises caused by the use of military sonars.
Scientists in the United States have discovered that, when exposed to mid frequency sounds let out by sonars used by the Navy, most whale species change their feeding behavior.
While some people tend to overeat when they feel stressed, whales more often than not respond to stressful circumstances by turning their backs on what specialists call high-quality prey.
Some might say that they go on a hunger strike.
In order to research how military sonars affect marine wildlife, the researchers tagged 17 blue whales swimming close to the Californian coastline and then simulated sonar sound waves.
“Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes.
“When a response occurred, behavioral changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. This type of behavioral response that involves cessation of feeding clearly results in reduced foraging efficiency,” Dr. Jeremy Goldbogen details his and his colleagues' findings.
Daily Mail explains that, once the whales have their feeding behavior altered, it is only a matter of time until they show signs of feeling weak.
Some manage to recover, but others progress from hunger to starvation and sooner or later die a slow and painful death.
The marine species affected first and foremost by underwater sonar sounds are the ones using low frequency sounds to communicate with others of their kind, and those relying on higher frequency clicks to track down their prey, the researchers say.
Some of these species are already listed as endangered or threatened.