Ocean Noise Pollution
The constant hustling and bustling in the oceans create unceasing unimaginable noise. 6000 commercial shipping vessels ply the seas permanently, as well as submarines and sonar (more than 300 are non-NATO), seismic offshore exploration for oil, gas and other minerals, more and more numerous offshore wind turbines, and, of course, the sounds from boats’ propellers and hulls as well as other recreational activities contribute to this racket...
The “silent world”, no longer appropriately named, has in other words become an unbearable cacophony for its inhabitants due to ever-increasing human activities.
According to researchers at the Monterey Bay Aquarium Research Institute, USA, the increasing ocean acidity may cause the marine environment to become even louder. Changes in the chemical composition of seawater would diminish the capacity to absorb low frequency sounds by 10% compared with the pre-industrial revolution era. Unless we reduce greenhouse gas emissions by 2050 (a path we are far from following...), the acidity of the oceans and seas could reach a level such that the noise of ships and guns earthquake would travel 70% farther than at present. No comment.
“Some” last strandings in September 2012
During the same weekend of 09/02/12, dozens of pilot whales were stranded on both sides of the Atlantic, the coast of Scotland and Florida. In North America, it was the third such incident in two days.
26 whales stranded in Scotland
On 02/09/12, a large group of 26 pilot whales (Globicephala macrorhynchus) were beached on the eastern coast of Scotland, near St. Andrews. Sixteen died, but rescuers managed to get the other ten back into the water.
It is believed that the seismic survey performed by the company M / V Polarcus Adira could be responsible for these beachings.
Two other groups of pilot whales were beached at Cape Cod, Massachusetts (North-eastern United States) on 09/01/12, and Canada 09/02/12.
22 whales stranded in Florida
On 09/01/12, 22 whales - only 5 were saved - were stranded on a Florida beach.
At the same time, the Sibylline association reminds us that the American company SeaWorld is the largest representative of the captive animals’ industry, which finances and manages safety operations where strandings occur and surviving animals can be found. Is it a coincidence that only young and very young animals have been rescued, while others were euthanized? These young animals were directed to one of the parks (“veterinary centres”), without the need for authorization, as they were declared not “rehabilitated”. So double whammy for SeaWorld: a huge advertising campaign promotes a very positive image of SeaWorld as a rescuer, and the financial transaction is excellent, since a pilot whale, should it be purchased, costs at least $ 250,000 dollars… So here they had five in one go...
The reason for these early September strandings is still yet to be determined.
Echolocation and sonar
Whales produce sounds (clicks, whistles, vocalizations), most of which are characteristic of the species or population by their shape, frequency and duration. They use echolocation systems similar to active sonar
, sometimes over long distances to locate their peers, their prey and their predators.
The increasing noise of oceans and marine environment disorients them, disperses and threatens their livelihood, and may lead them to extinction.
The stranding phenomenon is not recent: the first cetacean stranding was recorded in 1805. Since then around twenty strandings per year have been recorded until the 1960s. But the conclusion is obvious: since the 1960s, there is a sharp increase in cetaceans’ strandings. Of course information flows more easily since the mid-20th century, but is it simply because it is easier to know what is happening on the other side of the Earth, or is it because there are more and more accidents? Correlations have been made between US, British and Spanish Navies’ presence conducting naval manoeuvres with low frequency military sonar noticeable over 100km and cetaceans strandings. Remember that all Navies use the same kind of equipment, so all the seas of the world are affected by these “exercises”...
In 2000, in the Bahamas, a U.S. Navy experiment with a transmitter up to 230 dB in the frequency range of 3,000 to 7,000 Hz caused the beaching of sixteen whales, seven of whom were found dead. Two years later, the U.S. Navy finally recognized its responsibility in this stranding in a report published on 01/01/2002 in the Boston Globe.
The sound of military sonar generates problems in cetaceans’ decompression, followed very often by a stranding.
During their dive, whales experience space only through acoustic signals they receive and issue. For cetaceans, hearing is their most important sense. Their capacity to hear well is vital in all key aspects of their lives, such as finding food, travelling and socialising. Do you know that the auditory nerve of the dolphin is 10 times longer than the man’s one?
To breathe, they take their time, naturally respecting decompression “levels”. But under stress generated by colliding sonar waves, stress hormones are spread throughout the body, the heart rate increases and the leak is obvious: whales undertake a recovery emergency. As with divers, rising up too fast causes an accumulation of gas in the organs.
We know a little more about this phenomenon today thanks to the autopsy of bodies of stranded animals. Scientists discovered that the liver was full of gas bubbles (sometimes the size of a tennis ball), the kidneys ruined and fat particles were found in the blood.
Cetacean capture sound waves with their lower jaw, lined with highly vascularized adipose tissue. This serves as a resonance structure for echolocation.
However, sonar waves used by the Army – or air guns’ waves for offshore exploration for oil gas and minerals) - are responsible for bleeding in the inner ear of cetaceans and in the region of the lower jaw, as well as for fractures organs causing internal bleeding.
Animals die a slow death. Some of them lose their strength on the shores. Maybe they approach the land as a way to reach safety?
To understand a little better what these animals are enduring, imagine a comparable scenario: you are in the street and suddenly you hear a noise that makes you lose your sense of direction. The sonar’s intensity is stronger than a jet’s take-off. And it lasts several hours and not a few minutes. Feel your bones and flesh in your body vibrate because of the noise; your ears start bleeding. Since the noise generated by the sonar saturates the oceans for hundreds of miles by creating acoustic barriers is insurmountable for cetaceans, you cannot escape...
Research programs on cetaceans exist, but it is very difficult to have an independent study. In the United States, for example, the Navy funds research programs in marine biology. Only such studies would determine precisely the role of human activities in these strandings and the causes of the disappearance of these marine animals. But no chance to get the truth, as funding only comes from those directly involved…
We already know the consequences of noise on cetaceans. They affect all aspects of their lives, such as:
- Communication: the destruction of their echolocation system creates problems within the clan. Both males and females can no longer join.
- Education: the young have difficulties to learn the group codes and more often, they end up lost and stranded on beaches.
- Migration: forced to deviate from their normal routes, individuals of the same group eventually split up. The researchers found stranded cetaceans in places not usually frequented by these animals.
- The risk of famine: cetaceans are not able to locate their prey and thus feed.
Are there any solutions to reduce the impact of noise in oceans?
YES but, again, this is a political and financial question…
Among the mentioned solutions, here are a few:
- Change the sonar frequency BUT this is not a solution because other cetaceans’ species will be affected since each cetacean species has different characteristics of resonance clean.
- Walls of bubbles are generated at the foot of offshore wind turbines, on the sea bottom, to reduce their noise, a bit like anti-noise walls along our highways built to partially absorb the waves. The reduction is effective, but is it sufficient? ...
- The shipping industry has the manufacturing capacity of building « silent » vessels but it is expensive. And as to date, no national or international obligation has been set. Despite the recommendations made by scientists and associations for several years, nobody wants to pay.
- Ask Navies to check the cetaceans’ presence thanks to clicks they emit before they manoeuvre. This would imply a radical change of attitude in the military, whatever nationality they are. The Navies could hire marine biologists. They would have to keep their independence at the same time in order to determine impacts of sonar on the fauna’s disappearance. This measure could be quickly put in place but probably never will be...
- Create more areas where maritime traffic, military manoeuvres, offshore exploration, aquatic recreational activities are totally prohibited, as well as corridors to connect these quiet areas.
- Join associations that are fighting for these issues ... and talk about it around you and relay info via your networks to members of Parliament: we are public opinion and we can act.
To learn more :http://www.sounds-of-seas.info/