Oceanic Noise Pollution — Why Does it Matter?
Noise pollution is exactly what it sounds like: an excessive amount of noise that is taking away from the natural environment. When boats and machines are used in the ocean, they can create noise pollution that disturbs the peace under the water.
Sources of noise pollution
Where does noise pollution in the ocean come from?
One of the main sources of oceanic noise pollution is ship traffic. Over 90% of the world trade is sent by boat, according to the Animal Welfare Institute.
“…(industrial shipping is) producing an ever-present and rising aural “fog” that masks crucial natural sounds and is the most pervasive source of ocean noise today.” -AWI
Another source of noise pollution is sonar. Sonar is a way for humans to explore the ocean using sound waves, however it has deadly consequences on marine life.
The sound waves used in sonar can be used to detect objects far away underwater, and is a tool that the military uses often. These devices can be up to 194 decibels.
Oil drilling also creates an abundance of noise underneath the water. Oil drilling can be as loud as a rock concert, according to an article by Nature.
How are marine species impacted?
Many marine species rely on echolocation to navigate their way around the ocean and to track down prey.
Too much noise underwater can make it extremely difficult for these species to get around and hunt for food. This has been linked to behavioral changes and physical changes.
A study in 2015 showed that when squid were exposed to air gun noise pollution, they responded by swimming at lower depths and in closer groups.
They also found that some turtle species also responded to noise pollution by diving to lower depths.
This same study also found that in cichlid fish, their behavior was altered by a lower defense against their egg predators.
These fish also displayed a lower amount of digging and nesting, therefore throwing off their typical breeding habits. This could potentially lower this species population numbers.
Some species have also been found to abandon their habitats due to large amounts of noise pollution. These species then have a hard to acclimating to a new environment, and many undergo lots of stress.
In some cases, whales have even been found to breach themselves on beaches after being exposed to extreme noise.
How can we stop this?
There are many potential solutions to oceanic noise pollution.
Since commercial shipping produces a lot of the noise pollution around the world, one potential solution is the development of quieter propellers.
A company in Denmark was able to produce propellers that were 75% quieter than their usual ones, but they were incredibly expensive to produce. A low cost quiet commercial ship propeller still needs to be developed.
Changing the routes of these ships could also help reduce the amount of marine life impacted by their loud propellers. The routes could be adjusted to keep the ships away from typical feeding and breeding areas of species that are known to be impacted.
Another solution is to employ a lower-intensity kind of seismic vibrations.
Usually, seismic surveying uses pulses of compressed air to locate and find the way around the ocean. A new technique called “marine vibroseis” uses vibrations instead. These vibrations are much lower in sound intensity.
There is also a technique called “acoustic bubble curtains” that could lower the impact on marine species.
These have been used to reduce the noise that comes from pile drivers in the ocean.
The acoustic bubble curtains are made of perforated pipes that surround the pile drivers and blow air bubbles. This has been shown to reduce the noise by up to 15 decibels. This means the noise is reduced by 95%.
Oceanic noise pollution needs to be talked about more when discussing the environment, specifically ocean conservation. It is an important issue, even if it seems niche. The marine species affected deserve to live in peace under the waves.
