Oceanic noise pollution, the unseen rhythm that permeates the marine environment
The briny deep isn't as quiet as you'd think, not since the arrival of humans. Fact is, we've been creating more noise than we realize -auditory pollution- and our aquatic friends are suffering the consequences. Neus Pérez Gimeno, a research technician in underwater acoustics at the Institute of Marine Research, University of Cádiz, explained it best: humans are significantly deaf compared to marine creatures when it comes to detecting sound nuances.
At 9 minutes and 40 seconds, something fascinating transpires. Neus captures the subtleties through frequency, a sound characteristic measured in hertz (Hz). She elucidated, "For instance, whales have way more variation in the frequency range compared to us humans. They also respond differently to sounds."
The Not-So-Silent Damage
All that noise, you ask? It can do serious harm to marine life. Neus explains there are two categories of damage. The first consists of temporary disturbances, similar to those you'd experience after a concert: your ears feel a bit off, but you recover. The same goes for marine creatures, as noise can cause temporary hearing damage.
However, it's the permanent injuries that are the real concern. A very intense acoustic shock momentarily can cause serious harm, like burst eardrums, membrane ruptures, or even hemorrhages. Neus warns, "When this kind of damage occurs, mass strandings might happen." Throughout history, there've been several instances linked to seismic and military campaigns, although progress has been made to minimize the impact through technological advancements.
Pérez Gimeno also mentioned the adaptive nature of marine life. "Many studies show they are capable of adapting to environments with ship noise," she says. However, masking can happen, and marine life can mistakenly interpret man-made sounds as other animals, leading to collisions.
A Noisy Nation at Sea
In Spain, Renaud de Stephanis, director of CIRCE, an organization dedicated to the conservation of marine life, believes acoustic pollution is indeed a problem, but it should not be overemphasized. He shares a case in which noise does bother the creatures in the area: "Some dolphins hunt tuna by passive acoustics, making clicks that essentially work like sonar and help locate their prey. Too much noise can interfere with this process."
Maritime traffic is the leading offender in creating marine acoustic pollution. According to Francisco Javier Rodrigo Saura, director of operations at SAES, underwater electronics company, "The propeller is the main culprit (except at low speeds, like in port areas). Vibrations of the hull, generated by the engine and other boat devices, also contribute to acoustic pollution." Sound produced by ships is of low frequency and travels the farthest in the aquatic medium, the same frequency used by large cetaceans for communication. This interference can make communication difficult.
Regulating the acoustic pollution caused by ships while they navigate is challenging, as Neus Pérez explains: "The sea, from a legal standpoint, is a mess. There are zones of international waters, others shared... Like the Strait of Gibraltar, which is under the control of Spain, England, and Morocco. How do you legislate in such areas? It's complicated." Additionally, the flag state under which the ship sails determines its regulations, with vessels from certain countries—like Somalia or Cape Verde—not having the same requirements as those from European countries.
Bubbles, Seismic Surveys, and Other Sources of Noise
Other human activities at sea, such as seismic studies and construction, generate acoustic pollution that is sudden, brief, and intense. These studies, used to find out what lies beneath the seabed, involve using air cannons that emit noise above the threshold at which animals' auditory systems can be damaged.
Mitigating measures can be taken to avoid damage to marine life, like preventive measures, such as calibrating equipment well and ensuring no other campaigns are carried out in the area. A modeling process is also conducted, determining the noise the activity will create and at what distance it can affect cetaceans. Based on this area, an exclusion zone is set up, and cetaceans are observed visually and with sounds. If creatures are detected, the activity is paused until they move away.
Regarding offshore wind installations, there's ongoing debate regarding their impact on the environment. While it's established that they produce noise, it's not yet known to what extent it constitutes a risk to the environment.
In conclusion, controlling marine acoustic pollution requires a comprehensive approach that includes regulatory action, technological innovation, environmental assessments, continuous monitoring, and international cooperation. Either way, it's high time we started being mindful of the noise we're making and its consequences on our oceanic neighbors.
- In the realm of environmental science, a report has highlighted the issue of marine acoustic pollution, which is causing significant harm to various marine life species.
- Neus Pérez Gimeno, a researcher in underwater acoustics, has emphasized the importance of fitness-and-exercise and health-and-wellness for marine creatures, as they are sensitive to sounds in a way humans can hardly comprehend.
- Climate change and environmental science experts warn that sports activities like seismic surveys and offshore wind installations, when not managed properly, can lead to climate change by causing noise pollution in the ocean, disrupting the communication and daily activities of marine life, particularly large cetaceans.
