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I Many ocean creatures, such as whales, seals, sea lions and dolphins, experience their whole world through sound. Whales, for example, use low-frequency sound waves to keep track of each other, tell others where food is available, and find each other to breed. Whales that are sometimes hundreds or even thousands of kilometres away must listen very carefully to hear the faint sounds of these 'whale songs'.
I Unfortunately, in the last one hundred years, humans have begun flooding the oceans with noise, from off-shore oil drilling and the use of explosives for underwater mining, to shipping traffic and military operations. In fact, the ocean is ten times noisier than it was in 1960! As a result, sea creatures can no longer hear and communicate with each other. A blue whale born in 1940, for example, was able to hear sounds from up to 1,000 miles away. Today, this 'hearing bubble' has been reduced to only 100 miles, making it much harder for it to locate a mate. Evidence is also growing that sound blasts from military sonar are so intense that they cause bleeding of the eyes, ears and organs in whales and dolphins. Some also suspect that noise, even if it is quieter than the engine of an average motorboat, can cause whales and other mammals to swim miles away from breeding or feeding grounds, or even to become stranded.
I So, can anything be done about this? Well, environmentalists are currently campaigning for ships and oil companies to move away from areas where there are a lot of sea mammals. They also believe that there should be laws or at least international agreements to control noise levels at sea. However, they certainly haven't got an easy job! Many people don't even believe, or don't want to believe, that ocean noise can have such a drastic effect on animals.

anna1919191    1   22.03.2020 19:00    2