Noise pollution often takes a back seat in discussions of harmful pollutants, however, it can lead to a domino effect, leading to a loss of population diversity and over fishing in our oceans. Noise pollution is the propagation of anthropogenic sounds, such as machines and transportation that negatively impact human and animal activity. Man-made innovations such as sonar, gas and oil rigs, and boats are some of the leading causes of noise pollution. Noise Pollution can lead to the inability of marine organisms to effectively communicate and avoid predators, it also changes migration and feeding patterns, leaving less to reproduce. Because scientists do not fully understand how fish and other marine life communicates it is hard to completely understand the effects of noise pollution (Hawkins et al.). However, as time continues and numbers of populations drop, scientists are slowly discovering some of the mysteries of the ocean. Noise pollution harms marine life through, forced change in migration and breeding patterns, reduction in their ability to effectively communicate, and introduces the discovery of auditory over stimulation leading to health issues of marine animals, which leads to a decline in population and diversity of marine life especially around reefs. 

Certain species of marine life have specific migration paths and known areas for breeding. With an increase in commercial boating and oil or gas rigs, these paths are disrupted which can lead to smaller future populations. Human-generated noise is disrupting cycles that have lasted thousands of years undisturbed. Marine animals are forced to avoid areas with heavy human interference, which disrupts their ability to find food and mate. Researchers Francis and Barber noted, “…noise can impair sensory capabilities by masking biologically relevant sounds used for communication, detection of threats or prey, and spatial navigation…Increases in noise intensity…will increase the severity of the impacts, regardless of whether it is perceived as a threat or masks biologically relevant sounds” (Francis and Barber). The increased frequency of noise can disrupt many of the biological components of marine animals, “anthropogenic noise can cause physiological, neurological, and endocrinological problems; cognitive impairment; sleep disruption; and an increased risk of coronary disease” (Radford et al). Increased stress due to anthropogenic noise leads continues to worsen when marine animals are forced to live with noise pollution. A cycle is created when animals are constantly overwhelmed with the noise caused by sonar, boats, oil rigs, or other man-made technologies. They continue to be stressed and lose sleep, which makes them more at risk for serious problems such as coronary disease which continues to negatively affect their population and ability to reproduce. Man-made technologies force marine life to avoid necessary areas for breeding and feeding due to auditory sensitivity and increased human activity. Noise pollution causes a domino effect, harming marine life and forcing animals out of their habits, causing a decline in population and diversity among marine life.

Noise pollution comes in many forms of man-made technologies. Sonar technology is leading in underwater GPS and is now used for military operations, underwater research, and the mapping of unknown areas in the deepest depths of the ocean. With the continuing use of sonar in the military and scientific research, sonar’s effect on the stress levels of marine life has become somewhat apparent. Low-frequency sonar signals are constantly tested and reevaluated, however marine life, especially whales are in a constant battle against sonar emittance. Mass strandings of whales have become common as Navy vessels used mid-frequency active sonar. Whales communicate with each other through echolocation which is very similar to sonar technology and become easily confused by the mixed signals. Both the Navy and whales use frequencies between 100-500 Hz, which confuse the whales and stress them out to a point where they can die in the open water and end up stranded onshore. In a scientific review by Parsons et al. examined the correlation between naval military exercises and the increase in whale strandings:

“Worth specific note [is] at least eight mass strandings of beaked whales that have been associated with military exercises around the Canary Islands (Fernández et al., 2005b, ICES, 2005, Taylor et al., 2004). The most recent of these, in July 2004, involved four Cuvier’s beaked whales, Ziphius cavirostris, and coincided with the naval exercise “Majestic Eagle”…Fernández et al. (2005b) considered it highly probable that these animals died at sea, rather than stranding live and then dying onshore. This increases the concern that additional animals to those found beached may be affected during similar events and may die in open water, but are not being discovered and examined (Fernández et al., 2005b).” (Parsons, E.c.m., et al.)

Whale strandings have given scientists and insight into the effects of sonar and noise pollution in the open ocean. While we can study stranded whales on land, it is suggested that other marine animals can be affected but unseen because they do not wash up on our shores, but instead succumb to the ocean floor. With so many unseen effects of noise pollution, many scientists are unsure of what to do. Noise pollution’s effects on marine life can be seen in everything from fish to whales. They depend on auditory communication to migrate and breed, with too much noise they end up lost. Whales and fish have been recorded dying due to too much noise from boats, oil rigs, and sonar. 

 Sonar is a major factor in increased harmful effects in marine life. While it is easier to limit our military’s use of sonar, it is difficult to regulate sonar use from other countries, research projects, and onboard GPS in commercially used in boats. There is a minimal loss of energy by absorption in the sea, so it is normal to usually hear the surf and waves, fish moving, and organisms feeding in and around the reef (Kennedy, E.v., et al.). One of our main concerns with hearing loss in fish on the reefs is a decrease in survival rate which will cause an imbalance in the ecosystem leading to overfishing and destruction of habitats (Slabbekoorn, Hans, et al). However, Radford, A. N., et al. believe that given the right circumstances, fish could evolve beyond noise pollution and halt the domino process before populations and diversity in reefs are completely lost. While Radford may believe that some marine life can evolve beyond noise pollution and find new ways to communicate, it is important to remember that nothing is certain, our best bet at this point is to reduce the levels of noise pollution near reefs and away from important breeding and feeding grounds. Although genetic adaptations have been seen in species affected human interference in their natural habitats, and it is a possibility this can appear in certain species affected by noise pollution, there are no guarantees when researching contemporary problems. While scientists are not certain of the effects of noise pollution, it is officially classified as a pollutant by the international community. This means that scientists can use research collected from the effects of noise pollution of birds and apply it loosely to marine life (Radford, A.N., et al). Through studying the known effects of noise pollution scientists are able to compare data collected from species most likely to suffer harsher effects. Noise pollution is causing incomprehensible harm to marine life, caused by man-made technologies marine life that depends on auditory communication to breed, feed, and migrate are dying off due to noise pollution. This leads to a domino effect, eventually causing a decline in population and a loss of genetic diversity in important species.

Man-made machine activity around waterways increases the amount of noise marine life has to shift through to communicate with each other. With increasing use of sonar technology, construction to roads and bridges near waterways, and boating activity due to cruise ships and international shipping, marine life is drowned out by the noise around it. “Impeding the ability of fish to hear biologically relevant sounds might interfere with critical functions such as acoustic communication, predator avoidance, and prey detection, and use of the ‘acoustic scene’ or ‘soundscape’”(Slabbekoorn, Hans, et al).  Due to the increase in noise pollution, prey animals are less likely to hear their predators coming which increases prey species death rates. This is especially important to notice around reefs as communication between species is critical for survival. In a study done by Parsons, E.c.m., et al. they observed, “Current mitigation measures during military exercises are focused on preventing auditory damage (hearing loss), but there are significant flaws with this approach. Behavioral responses, which occur at lower sound levels than those that cause hearing loss, maybe more critical” (Parsons, E.c.m., et al.). Although there are some litigations about how to reduce our effect on marine life, our lack of understanding of how marine organisms communicate and function is still out of our reach. The use of machinery in the ocean and near waterways continues to contribute to lower levels of communication in communities in and around reefs and an increase in death rates of prey species, which leads to a lack of genetic diversity and overfishing.  

Noise pollution is not as openly debated as climate change or even light pollution, however, noise pollution is doing its part in dismantling marine life and needs to be included in these discussions. Noise pollution causes increased stress in marine life which can become so extreme that they die. Scientists have been able to research the connection between active military sonar missions and the increased number of stranded whales on the shores that correlate the mission times. However, with smaller animals, it is almost impossible to tell the effect of noise pollution in the open ocean because they are usually lost at sea. In reefs nevertheless, the data scientists have collected describe a different story. Researchers have just been able to scratch the surface of auditory communication between varying organisms living on the reef. They are able to analyze how recent human-activity negatively affects communication. While it is important to continue research on reefs, scientists need to focus more energy on researching the effects in the open ocean. Due to the fact that it is harder to study the effects in the open ocean, it is necessary that we move forward in researching harder to study areas as they will hopefully shine a light on the continuing mystery of noise pollution. Noise pollution is causing harm to marine life through forced change in migration and breeding patterns, a reduction in the ability to have effective auditory communication, and the consequences of man-made technology on the well being of marine life, which causes a decline in population and a loss in the diversity of marine life.

Works Cited

Francis, Clinton D, and Jesse R Barber. “A Framework for Understanding Noise Impacts on Wildlife: an Urgent Conservation Priority.” Frontiers in Ecology and the Environment, vol. 11, no. 6, 8 Aug. 2013, pp. 305–313., doi: https://doi.org/10.1890/120183.

Hawkins, Anthony D, et al. “Information Gaps in Understanding the Effects of Noise on Fishes and Invertebrates.” Reviews in Fish Biology and Fisheries, vol. 25, no. 1, Mar. 2015, pp. 39–64., doi:https://doi.org/10.1007/s11160-014-9369-3.

Kennedy, E.v., et al. “Spatial Patterns in Reef-Generated Noise Relate to Habitats and Communities: Evidence from a Panamanian Case Study.” Journal of Experimental Marine Biology and Ecology, vol. 395, no. 1-2, 9 Sept. 2010, pp. 85–92., doi:https://doi.org/10.1016/j.jembe.2010.08.017.

Parsons, E.c.m., et al. “Navy Sonar and Cetaceans: Just How Much Does the Gun Need to Smoke before We Act?” Marine Pollution Bulletin, vol. 56, no. 7, 4 June 2008, pp. 1248–1257., doi:https://doi.org/10.1016/j.marpolbul.2008.04.025.

Radford, A. N., et al. “Acoustic Communication in a Noisy World: Can Fish Compete with Anthropogenic Noise?” Behavioral Ecology, vol. 25, no. 5, 11 Mar. 2014, pp. 1022–1030., doi:https://doi.org/10.1093/beheco/aru029.

Slabbekoorn, Hans, et al. “A Noisy Spring: the Impact of Globally Rising Underwater Sound Levels on Fish.” Trends in Ecology & Evolution, vol. 25, no. 7, 2010, pp. 419–427., doi:https://doi.org/10.1016/j.tree.2010.04.005.