There are many different kinds of pollution. For example, light pollution in cities is what prevents you from seeing the stars at night. Meanwhile electromagnetic pollution may disorient birds and cause problems for our own electronics. Then there is air pollution, water pollution, soil pollution and so on, and so forth. But did you know that marine animals are suffering from acoustic pollution as well? Scientists at the University of Tasmania found that everyday marine noise from human activity can seriously harm lobsters.
Sound pollution is impacting everyone. Cities are never silent and it does affect both people and animals. But seas are not exactly quiet either. Ships are causing a lot of noise, as well as drilling platforms and various coastal activities. Scientists decided to see how sound pollution is affecting lobsters living close to a high-traffic shipping lane in Hobart. They compared them with lobsters that live in a quiet remote area and found that sound pollution is causing damage, which resembles damage caused by seismic air guns.
Previous studies have analyzed the damage done by seismic exploration. It’s been determined that seismic air guns, used in search of oil and gas, are very dangerous for scallops, zooplankton and lobsters. But then again – seismic air guns can create noises that are very close to the loudest sounds humans can make. This new research shows that noise caused by shipping is not much better. Scientists were actually surprised to discover that a water pumping station and ships passing by can inflict similar levels of damage on spiny lobsters.
Dr Ryan Day, lead author of the study, said: “The lobsters from a noisy area that we studied suffered damage to their statocyst, an organ comparable to the human ear, which helps to control their position in the water, movement and righting reflex. The impact was comparable to that in lobsters exposed to air guns but, interestingly, their behaviour and righting reflex did not seem impaired, suggesting they had adapted to cope with their noisy environment”.
Seismic air guns create sharp, high-intensive signals, but that kind of noise is very short. Meanwhile ships and pumps create less intense, but a continuous and lower frequency noise that pretty much never goes away. In the site of the study the noise level was 5-10 decibel greater than in the remote area. This is equivalent to 3-10 times higher noise intensity.
Noise pollution is real pollution. It is damaging the environment – intense man-made noises are damaging various wildlife forms. But so far it is difficult to imagine ways how marine noise pollution could be reduced. Maybe new engines and propellers will help.
Source: University of Tasmania