Throughout Earth’s oceans, approximately 2,270 species are listed as threatened or endangered (“Endangered Ocean,” n.d.). These species of fish, mammals, and more have to compete with rising ocean temperatures, abiotic physical pollution, increased acidification, and more to live in their habitats. However, there is one threat to marine population health and safety that often goes ignored: noise pollution. Tools such as military sonar, seismic airguns, and boat motors create intense, overwhelming noise that takes many different forms and can cause a multitude of problems.
Supporters of these tools argue that they are necessary for many industries that rely on or cross the ocean. For example, loud motors are used to power vessels that ship foreign goods across the ocean. Unfortunately, ship traffic increased by more than 200% between 1950 and 2000, effectively doubling the ambient volume of the ocean every 10 years (Jones, 2019). Sonar is used to search for underwater hazards and develop ocean floor maps, as well as monitor for potential military threats. The biggest offenders are the seismic airguns, which are celebrated for their “predictable, repeatable, and controllable” blasts of air (“Marine Seismic Sources Part I,” 2010). These devices are used to search for oil and natural gas under the ocean floor, and emit sound waves at approximately 245 dB (“Marine Seismic Sources Part I,” 2010), which is about 18 times as loud as the average vacuum, and well over the safety standards for humans set in place by the U.S. Occupational Safety and Health Administration (“Safety and Health Topics | Occupational Noise Exposure,” n.d.). Above these levels humans and other animals can experience physical damage to the structures of the middle and inner ear.
Aside from physical damage to the ear, high-impact pulses can hinder physiological functions, such as social communication, embryonic development, neural function, and prey detection. Many animals, such as whales, use sound to communicate underwater because it travels well over long distances, and the ambient noise of the ocean has very little overlap with their natural tones. This creates a phenomenon called “acoustic masking, wherein anthropogenic sound overwhelms organisms’ natural calls, which disrupts communication and can lead to difficulty feeding, mating, and finding their way back to the pod (“Managing Underwater Noise Pollution,” 2018).
Such invasive and overwhelming noise not only poses the obvious threat to organisms’ ability to use sound to communicate and locate food, but it can also interfere with their physiology so much that they are unable to properly reproduce and develop due to long-term stress responses that systemically depress immune functions (Huntingford et al., 2006; Kunc, McLaughlin, & Schmidt, 2016; Nedelec et al., 2014). A body and brain that are constantly experiencing stress will reduce their homeostatic mechanisms that keep everything working properly and instead focus on maintaining a fight-or-flight attitude — thereby ignoring vital systems. For developing fry, larvae, or calves, constant sonic battery can physically damage reproducing cells which leads to physiological abnormalities that are not survivable in the wild (Kunc et al., 2016).
The situation would not be so dire if there were only one or two airguns working in the ocean at any moment, but experts suggest that at any point in time there are between 20 and 40 seismic surveys underway around the world, each one made up of multiple boats with up to 48 guns, each firing approximately 5 or 6 times a minute (Robbins, 2019; “Seismic Surveys,” n.d.). Even worse, in 2017 Trump signed an executive order to expand drilling and surveying off the coast of the United States.
This overwhelming noise, in conjunction with habitual overfishing by the seafood industry, will only serve to exacerbate the current anthropogenic mass extinction event and eliminate thousands of beautiful and vital species from our planet. For example, the Smithsonian Institute reports that multiple salmon species are now listed as endangered or critically endangered (“Endangered Ocean,” n.d.). Research in Norway suggests that when seismic surveys are performed in or nearby commercial fishing areas, local fishermen return to the docks with up to 80% fewer fish than when such exploration is not occuring. If one or both of these practices are not dramatically reduced, we could lose an industry valued over $5 billion, and destroy part of what makes this world so wonderful to live in.
(Kunc et al., 2016)
Endangered Ocean. (n.d.). Retrieved November 11, 2019, from Smithsonian Ocean website: http://ocean.si.edu/conservation/solutions-success-stories/endangered-ocean
Huntingford, F. A., Adams, C., Braithwaite, V. A., Kadri, S., Pottinger, T. G., Sandøe, P., & Turnbull, J. F. (2006). Current issues in fish welfare. Journal of Fish Biology, 68(2), 332–372. https://doi.org/10.1111/j.0022-1112.2006.001046.x
Jones, N. (2019). Ocean uproar: Saving marine life from a barrage of noise. Nature, 568, 158–161. https://doi.org/10.1038/d41586-019-01098-6
Kunc, H. P., McLaughlin, K. E., & Schmidt, R. (2016). Aquatic noise pollution: Implications for individuals, populations, and ecosystems. Proceedings of the Royal Society B: Biological Sciences, 283(1836), 20160839. https://doi.org/10.1098/rspb.2016.0839
Managing Underwater Noise Pollution. (2018, November 16). Retrieved November 11, 2019, from U.S. National Park Service website: https://www.nps.gov/articles/canyouhearmenow.htm
Marine Seismic Sources Part I. (2010, January 1). Retrieved November 11, 2019, from GEO ExPro website: http://www.geoexpro.com/articles/2010/01/marine-seismic-sources-part-i
Nedelec, S. L., Radford, A. N., Simpson, S. D., Nedelec, B., Lecchini, D., & Mills, S. C. (2014). Anthropogenic noise playback impairs embryonic development and increases mortality in a marine invertebrate. Scientific Reports, 4, 5891. https://doi.org/10.1038/srep05891
Robbins, J. (2019, January 22). Oceans Are Getting Louder, Posing Potential Threats to Marine Life. The New York Times. Retrieved from https://www.nytimes.com/2019/01/22/science/oceans-whales-noise-offshore-drilling.html
Safety and Health Topics | Occupational Noise Exposure. (n.d.). Retrieved November 11, 2019, from Occupational Safety and Health Administration website: https://www.osha.gov/SLTC/noisehearingconservation/
Seismic Surveys. (n.d.). Retrieved November 11, 2019, from Beachapedia website: http://www.beachapedia.org/Seismic_Surveys