When swarms of whales jump to the coast en masse to "commit suicide", people wonder who disturbed them? When the giant ship drove by, the dolphins fled out of the water in panic, and the noise "disturbed the people" was visible...
Let's take a look at the specific harms of marine noise pollution to marine life!
Effects of noise on biological behavior
Noise can cause marine animals to change the laws of life, such as changing the rules of floating and diving, changing the form of pronunciation (volume and rhythm), etc., and even causing them to be unable to avoid obstacles and have "fatal" collisions.
Beluga whales, for example, sound-producing marine mammals, react most strongly to noise pollution. At a distance of 50 kilometers from the ship, the beluga whale will produce a series of reactions, such as quickly swimming away from the ship, swimming out of the water to breathe, and changing the dive time. After long-term influence, the number of individuals in the population decreases, and the vocalization will be more acute. According to scientists, the noise generated by sonar interferes with the ability of whales and dolphins to use sound to prey, frightening certain cetaceans, especially protrusion whales, prompting them to rush out of the water, with dangerous consequences.
Effects of noise on biological hearing
Marine animal exposure to high-intensity sounds may result in temporary hearing loss or decreased sensitivity. When the sound intensity is high enough, it will lead to permanent loss of hearing in animals, or permanent weakening of sensitivity.
At the same time, scientists have also shown that bottlenose dolphins within 100 meters of the piling site will have damage to their hearing organs according to the effects of underwater piling machines on bottlenose dolphins during the construction of offshore wind farms; bottlenose dolphins within 50 kilometers may behave abnormally or be forced to avoid.
bottlenose dolphin
Noise causes lesions of biological organs
A study of 87 cephalopods (including two species of squid, an octopus and a squid) exposed to low-frequency noise showed that these animals experienced varying degrees of damage when exposed to low-frequency noise at frequencies of 50 to 400 Hz and sound intensities of 157 to 175 decibels (similar to oil and gas exploration noise) for two hours.
The animal dissection after the end of the experiment found that the animals dissected immediately showed signs of balancer damage, and the tiny hairy structure of the cells disappeared; the dissected animals suffered more serious damage after 96 hours, and their balancers appeared significantly large holes. Animals tested at the last moments of life only move their bodies slightly, and no longer swim, eat, or mate.
Noise causes biological deaths
According to the Natural Resources Defense Council (NRDC), the noise generated by military sonar can affect the long-term behavior of marine life and can lead to hearing loss or even death. Studies have shown a strong correlation between sonar and whale mortality, and a large number of whale strandings and deaths caused by mid-frequency sonar trials are occurring.
As early as May 1996, during a NATO exercise by the US military, 14 sword-nosed whales ran aground off the coast of Greece; in July 2002, 66 pilot whales committed collective suicide in Cod Horn, Massachusetts, USA, for the same reason related to sonar experiments; in March 2009, shortly after the USS Flawless opened its sonar in the South China Sea, an adult humpback whale trek more than 10 meters long ran aground on the coast of Hong Kong within the scope of sonar action.
In short, the impact of marine noise pollution on marine life is very large, and the consequences are multifaceted, complex and have a chain reaction.
In order to protect marine life, we should formulate laws, regulations and norms related to marine noise pollution as soon as possible, create a "quiet" atmosphere for them, and give them an originally beautiful home.