The Not-So-Silent Killer of Natural Ecosystems – Making Less Noise is as Important as Picking Up Our Trash

This map depicts how Pueblo's noise levels compare to the rest of Front Range Corridor - photo credit: Dept. of Transportation

If you’ve spent any time in the outdoors, you’ve heard of the concepts of “leave no trace” and “pack it in, pack it out.” Maybe you adhere to all of the principles. You dispose of all of your trash properly and store all of your food responsibly when hiking or camping. You use biodegradable soap when bathing out in the wilderness. You opt for reusable eating utensils over plastic, and cloth napkins over paper towels.

Say you pride yourself on being so thorough when breaking camp that anyone who utilizes your spot after you wouldn’t be able to tell you were there in the first place. These are all great practices. But what if I were to tell you that even the music playing from your portable speaker is a form of pollution? That the revving engine of your ATV or dirt bike inflicts as much damage to the surrounding ecosystem as the Snickers wrapper you accidentally dropped?

Noise pollution is one of the most common and overlooked forms of pollution caused by humans. When we think about pollution, visions of heaping trash and thick smog clouds come to mind. We commonly associate these images with industrial sites and highly populated, urban landscapes. But even the most remote of natural spaces can be affected by noise pollution, which researchers define as: “any clamor caused by man.”

It seems like a relatively new concept, but actually noise pollution has been an issue for a while now. In 1972 the federal government passed the Noise Control Act in order to target major sources of noise in urban areas and “promote an environment for all Americans free from noise that jeopardizes their health and welfare.” While the dated policy mainly focuses on noise produced by commerce and its affect on human health and safety, modern day noise pollution has a closer connotation with its affect on plant and animal ecosystems.

In 2007, Colorado State University partnered with the National Park Service to create the Sound and Light Ecology Team. With the help of modern predictive computer technology, the team used collected audio recordings from close to 500 protected sites around the U.S. and determined that noise pollution doubled sound in nearly two-thirds of U.S. parks.

To put that in perspective: noise caused by humans diminished natural sound in these areas by a whopping 90 percent. An animal inhabiting these areas that may have been able to hear 100 feet away in previous years when noise pollution was less prominent can only hear 10 feet away in the same area today.

Diminished soundscapes cause major disruption to natural ecosystems. For one, the increased noise pollution can throw off the predator to prey ratio by making it harder for typically prey animals to detect oncoming predators. This has the potential to impact entire food chains as prey populations decrease, predators are driven to seek food in areas outside of their natural habitats – which can include places closer to roadways, residential neighborhoods and other places more heavily inhabited by humans.

Noise pollution can also threaten the population of native plant species. For example, the Pinõn Pine tree – a prominent species of plant in Southern Colorado – depends on collector birds to spread its seeds. When a Pinõn drops its seeds, the birds are able to hear when they hit the forest floor and retrieve the seeds before ground-dwelling animals such as mice can eat them. In places with high noise pollution, fewer birds can hear the seeds dropping and thus, fewer birds retrieve the seeds. Most of the seeds then end up being consumed by mice, and never grow into adult plants.

Traffic on land and in the air accounts for a majority of noise pollution in the U.S. But machinery like oil and gas wells, generators, power lines, etc. constantly produces low bass-like frequencies that can travel for miles. Meaning that many of the places we consider “untouched” by man are actually inundated by manmade noise.

The damage inflicted by noise pollution doesn’t end at the ocean either. Researchers from the University of Saskatchewan published a report just last year on the negative effects of noise produced by watercraft motors, military SONAR and offshore development on marine life.

Progress continues to be made toward solving the noise pollution problem. The establishment of “noise corridors” to confine manmade noise to particular areas is one such solution. In 2013, the Federal Aviation Administration agreed to reroute air traffic above Trail Ridge Road in Rocky Mountain National Park in attempt to limit aircraft noise in the park. The shuttle system at Hanging Lake aids in keeping vehicular noise levels at a minimum inside the natural site. But just like recycling, or any other conservation effort: real change starts at the individual level.

If you’re like me, you may be guilty of deliberately making noise when camping and hiking in order to ward off bears or mountain lions. But this mentality is born out of fear more than anything, and isn’t all that effective. Bears, mountain lions and other wildlife have a far more developed sense of hearing than humans. Even more developed than their hearing is their sense of smell. They know when we’re around.

Examining our own habits and being conscious of the amount of noise we produce personally when embarking in the great outdoors is the key to cutting down noise pollution on a grand scale. Using headphones instead of a speaker, parking the car a ways off from the campsite or trailhead, and refraining from shouting or talking unnecessarily loud are examples of little things we can do that in time will greatly reduce our “noise footprint.”

The sounds of nature have been proven to be restorative to human health. Here’s an exercise for you the next time you’re out on the trails: sit somewhere comfortable, close your eyes and really listen to the birds, the water, the rustling of the wind in the trees. Notice how the roaring of traffic from a distant highway, the mechanical scream of an airplane passing overhead, or the thrumming of nearby power lines intrude on these delicate soundscapes. Undoing our developed desensitization to the constant background noise that permeates modern society takes a deliberate effort. Once we tap back into our awareness of these non-natural sounds, we won’t be able to un-hear them.