Noise pollution is mostly considered a city problem, but an extensive new study shows that it’s not just limited to cities. Scientists found that noise is polluting more than 60% of the natural protected areas in the United States. It has a direct impact on the wild animals’ ability to communicate, hunt, and survive. The sources of noise range from airplane engines, cars, oil and gas exploration, motorcycles, timber and mining activities, booming radio music, and general human development.
Noise in 63% protected areas is 2x the natural sound levels
Details of the study were published Friday in the journal Science. To determine the extent of noise pollution, researchers led by Rachel Buxton of the Colorado State University analyzed recordings at 492 national parks and protected sites across the United States. They studied millions of hours of recordings using a computer algorithm. The algorithm allowed scientists to subtract the natural sound levels from the existing levels.
The study revealed that human noise had doubled the background sound levels in 63% of the natural protected areas. About 21% of the protected areas showed a 10x or higher increase in background sound levels. Buxton said it gives us an idea of how human-caused noise affects the acoustic environment. Such noise pollution has reduced the area where natural sounds can be heard by 50-90%.
For instance, if you could formerly hear something at 100 feet away, now you’ll be able to hear the same thing from 10-50 feet. The added noise could have a huge impact on wild animals because it directly interferes with their communication. If a predator is listening for prey, noise could mask the sound and reduce the hunting efficacy. Or a prey might not be able to hear a predator approaching. Noise pollution also makes it harder for birds to find a mate.
Noise pollution could cause behavioral changes in animals
Scientists said even if just one species is directly affected by the noise pollution, the impact may spread throughout the ecological community. George Wittemyer, one of the co-authors of the study, said noise pollution could also lead to behavioral changes in animals. For example, some animals may have to spend more time being vigilant than foraging.
The airplane engines have changed the whole experience of remoteness. You can be in a remote area and still hear the loud jets overpassing. Buxton said the pollution is even worse in protected areas near airports and high densities of roads.
Solving the problem will be a major challenge. Buxton and her colleagues said the issue must be addressed at individual sites.