‘Noise pollution’ threatens fish

By Matt Walker
Editor, Earth News

Fish are being threatened by rising levels of man-made noise pollution. So say scientists who have reviewed the impact on fish species around the world of noises made by oil and gas rigs, ships, boats and sonar. Rather than live in a silent world, most fish hear well and sound plays an active part in their lives, they say. Increasing noise levels may therefore severely affect the distribution of fish, and their ability to reproduce, communicate and avoid predators. “People always just assumed that the fish world was a silent one,” says biologist Dr Hans Slabbekoorn of Leiden University, The Netherlands. But in the journal Trends in Ecology and Evolution, Dr Slabbekoorn and colleagues in The Netherlands, Germany and US report how the underwater environment is anything but quiet. So far, all fish studied to date are able to hear sounds, either by an inner ear or a lateral line that runs along a fish’s side. … “The level and distribution of underwater noise is growing at a global scale but receives very little attention,” says Dr Slabbekoorn. To date, most research has focused on the impact sound might have on marine mammals, such as whales and dolphins. But noise pollution might severely affect the distribution of fish, and their ability to reproduce, communicate and avoid predators. For example, some studies have reported that Atlantic herring, cod and blue-fin tuna flee sounds and school less coherently in noisy environments. …