Once thought to be a peaceful place, the undersea world is today a clamor of human-made noises, and the threat of aquatic noise pollution is becoming a serious environmental issue. Anthropogenic activities like shipping and marine seismic surveys are rapidly upsetting marine ecosystems, which are teeming with species that depend on sound for survival, communication, and navigation.

These activities introduce intense, low-frequency sounds that travel vast distances underwater, altering the natural soundscape. A 2023 report claims that underwater noise emissions in EU waterways doubled from 2014 to 2019, underscoring the growing effects of human activity on marine life. The threat of aquatic noise pollution is examined in this article, with particular attention paid to shipping and marine seismic surveys, their impacts on marine life, and possible remedies to lessen this expanding problem.

Understanding Aquatic Noise Pollution

Aquatic noise pollution refers to the introduction of anthropogenic sounds into marine environments, disrupting the natural acoustic balance. Unlike terrestrial noise, underwater sound travels faster and farther—approximately 4.5 times faster than in air, covering distances up to thousands of kilometers. Marine species, from whales to fish and invertebrates, depend on sound for critical life functions such as echolocation, mating, and predator avoidance.

The threat of aquatic noise pollution lies in its ability to mask these vital sounds, causing stress, behavioral changes, and even physical harm. Sonar can alter the feeding behavior of endangered blue whales, as shown in an experiment in Southern California. Despite lower sound levels, whales stopped feeding, increased swimming speed, and moved away, impacting their fitness and health.

Marine Seismic Surveys: A Sonic Assault

a. How Seismic Surveys Work

Marine seismic surveys, primarily used for oil and gas exploration, employ airguns that emit powerful, low-frequency sound waves to map the seafloor. These airguns produce sounds of up to 260 decibels, fire every 10 seconds for weeks or months, and penetrate deep into the ocean floor. Since the sound can travel over 4,000 kilometers and impact large areas, the threat of aquatic noise pollution from these surveys is substantial. These activities have a wide ecological influence, as evidenced by a 2025 NIH study that found seismic airgun shots changed the physiology and behavior of fish species in lake ecosystems.

b. Impacts on Marine Life

The intense noise from seismic surveys poses a severe threat to aquatic noise pollution to marine mammals, fish, and invertebrates. Cetaceans, such as whales and dolphins, experience reduced sightings during active surveys, with a 2019 study reporting an 88% decrease in baleen whale sightings and a 53% decrease in toothed whale sightings in areas with active seismic operations. These disruptions can lead to displacement from critical habitats, reduced feeding opportunities, and impaired communication. Invertebrates like zooplankton, crucial to the marine food web, face mortality rates near seismic sources, with a study indicating that airgun blasts can decimate zooplankton populations within a 1.2-kilometer radius.

Also Read: Planet’s Darkening Oceans Could Disrupt Marine Ecosystems, Scientists Warn

Shipping: The Persistent Hum of the Oceans

a. The Role of Commercial Shipping

Commercial shipping is a primary contributor to the threat of aquatic noise pollution, with global shipping traffic doubling low-frequency noise levels every decade since the 1960s. Ships generate continuous noise through propellers and engines, often reaching 190 decibels, comparable to a jet engine. This persistent hum disrupts marine ecosystems, particularly in busy shipping lanes. A 2024 report from the International Maritime Organization noted that shipping noise increased by 32-fold along major routes over the past 50 years, driving marine animals away from vital breeding and feeding grounds.

b. Effects on Marine Mammals and Fish

Marine animals are especially susceptible to shipping noise because they depend on sound for communication and navigation. In the Arctic, for example, beluga whales have been seen exhibiting signals of stress and displacement by changing their behavior up to 80 kilometers away from icebreaking vessels. Fish are also at risk from aquatic noise pollution; a study published in Marine Biology found that long-term shipping noise raises stress hormone levels in cod, which has an effect on the fish’s ability to reproduce and thrive. Fisheries and predator-prey dynamics are impacted by these disturbances, which have been shown to reduce capture rates by as much as 50% in the vicinity of seismic survey sites in the North Atlantic.

Ecological and Economic Consequences

The threat of aquatic noise pollution extends beyond individual species to entire ecosystems and human livelihoods. Marine ecosystems are interconnected, and disruptions to key species like zooplankton or fish can destabilize food webs, affecting predators like whales and commercially important fish stocks.

In the Barents Sea, seismic surveys disrupted cod and herring migration routes, leading to a report documenting a decline in commercial fishery yields in affected areas. As fish stocks diminish or migrate offshore, raising operating expenses, coastal communities that depend on fishing experience financial hardship. Furthermore, noise-induced stress in marine mammals might impair reproductive success and jeopardize population stability. For example, whales may have higher cortisol levels.

Also Read: Global Warming Has Tripled Marine Heatwave Duration Since 1940, Study Finds

Vulnerable Species and Habitats

Certain species and habitats are particularly susceptible to the threat of aquatic noise pollution. Endangered species like the North Atlantic right whale face heightened risks, with only about 350 individuals remaining as of 2025. Seismic surveys in biologically rich areas, such as the Northwest Atlantic near Cape Hatteras, exacerbate threats to these populations. Arctic regions, once acoustic refuges due to sea ice, are now experiencing increased noise from shipping as the ice melts, impacting species like narwhals and Indigenous communities reliant on marine mammals. A 2025 WWF Arctic report highlighted that underwater noise in the Arctic travels closer to the surface, amplifying its impact on marine life.

Conclusion

The threat of aquatic noise pollution from marine seismic surveys and shipping is a pressing challenge that demands urgent action. With underwater noise levels rising—doubling in EU waters from 2014 to 2019—marine life faces unprecedented disruptions to communication, behavior, and survival. These operations, which include the thunderous blasts of seismic airguns and the constant buzz of shipping, put human livelihoods, ecosystems, and animals in jeopardy. We can lessen this imperceptible but terrible contaminant by embracing quieter technologies, enforcing stronger laws, and encouraging research and education. The ocean’s symphony, vital to its inhabitants, deserves to be preserved for future generations.

Also Read: The Interconnectedness Of Marine Biodiversity And Human Health