The changes were discovered by studying the life of marine life, from tiny snapping shrimp to huge southern whales.
“Sounds travel very far underwater. For fish, sound is probably a better way to sense the environment than light, for example, ”says Francis Juanes, an ecologist at the University of Victoria in Canada.
Many fish and marine animals use sound to communicate with each other, to identify promising breeding or feeding grounds, and possibly to spot predators. For example, clicking shrimp makes a popcorn-like sound that stuns their prey.
Increased noise from shipping, motorized fishing vessels, subsea oil and gas production, offshore construction and other human activities impedes the communication of marine life. These noises replace the familiar sounds of the depths, as they tend to oscillate around the same low frequencies that fish use.
As a result, in some parts of the ocean, scientists are recording a decline in many “singing and screaming” marine animals. Judging by the data of underwater microphones, their voices (and therefore the inhabitants themselves) have disappeared from the vast territory in the Red Sea – since 1970 their number has decreased by half.
The Red Sea is considered one of the world’s major shipping corridors. It is filled with large ships bound for Asia, Europe and Africa, so the noise pollution is significant.
But the good news is that dealing with noise pollution is easier than dealing with the proliferation of plastic or global warming. “Theoretically, the sound can be reduced or turned off in the same second,” the scientists say. You cannot do this with other environmental problems.