Underwater Noise Pollution Studies

The ocean is getting louder — and fish are paying the price. 🌊🔊 We usually think of marine pollution as something visible: plastic waste, oil spills, or discolored water. But beneath the surface, sound has become a growing source of stress for marine life. Research shows that human-made underwater noise (from commercial shipping, sonar, and offshore activities) is fundamentally altering fish behavior: 🔹 Migration patterns change. 🔹 Feeding efficiency decreases. 🔹 Reproductive success is affected. Because sound travels faster and farther underwater than in air, what seems like background noise to humans becomes a constant disturbance for fish. This issue goes beyond ecology. It directly impacts fisheries, food security, and the long-term stability of marine ecosystems. Marine pollution is not always visible. Sometimes, the most dangerous threats are the ones we cannot see. ❓ Do you think current maritime regulations focus enough on acoustic pollution, or is it still an overlooked issue? #MarineScience #OceanHealth #UnderwaterNoise #Fisheries #MarinePollution #Sustainability #EnvironmentalScience #MarineBiology

Reducing underwater noise is no longer just an environmental issue — it is a strategic priority for sustainable shipping. German researchers have commenced a €3.9 million project aimed at reducing cavitation noise from ship propellers a major contributor to underwater radiated noise (URN). Cavitation occurs when vapor bubbles form and collapse around a rotating propeller blade, generating noise, vibration, and efficiency loss. Beyond structural implications, this underwater noise disrupts marine ecosystems, particularly marine mammals that rely on acoustic communication. This initiative highlights three important industry shifts: 🔹 Sustainability beyond emissions: While decarbonization dominates maritime discussions, underwater noise mitigation is becoming equally critical. 🔹 Advanced hydrodynamic design: Optimized propeller geometry, wake adaptation, and improved hull–propeller interaction can significantly reduce cavitation. 🔹 Digital simulation & testing: CFD modelling, cavitation tunnels, and acoustic measurement technologies are driving evidence-based improvements. From a maritime academic perspective, this is a strong reminder that ship efficiency, environmental stewardship, and technological innovation are deeply interconnected. For emerging maritime nations like Bangladesh, investment in hydrodynamic research, propeller optimization, and marine acoustic studies could position us competitively in green ship design and retrofitting markets. The future of shipping is not only quieter in terms of emissions it must also be quieter beneath the surface. #MaritimeInnovation #SustainableShipping #GreenShipping #NavalArchitecture #Cavitation #MaritimeResearch Source: Marine Insight

The Arctic is getting louder and our approach to underwater noise policy is lagging behind reality. New research led by the University of Bath shows that as Arctic ice conditions change, underwater soundscapes are becoming more complex, more variable, and measurably louder. Long-term acoustic observations from Cambridge Bay (Nunavut, Canada) reveal something critical: anthropogenic noise in the Arctic is not confined to traditional “shipping bands” or even to shipping alone. Aircraft, snowmobiles, small vessels, and ice-related processes all contribute across a much broader frequency range. In other words, the way we measure underwater noise is no longer aligned with how noise is actually generated or experienced in polar environments. This matters for policy. Current approaches, often reliant on narrow frequency indicators, proxy data such as AIS, or models developed for open-water, temperate systems, risk under-representing real exposure levels in the Arctic. The research makes a clear case for broadband, region-specific, in-situ acoustic baselines as a prerequisite for meaningful management. From a science and policy interface perspective, the next challenge is speed and scalability. We are collecting more acoustic data than ever, but regulatory relevance depends on how quickly that data can be processed, interpreted, and translated into action. As activity in the Arctic accelerates, static, retrospective assessments will not be sufficient. The takeaway is clear: if policy and legislation are to remain fit-for-purpose, in Canada and globally,  they must evolve alongside the science. That means modernizing how we measure noise, broadening what we consider “impact,” and ensuring acoustic evidence can inform decisions on operational timescales, not years later. The Arctic is changing fast. Our acoustic frameworks need to change with it. Read the article: https://lnkd.in/ejdhgJpj Read the peer-reviewed paper: https://lnkd.in/eTiM_vMy

IMPACTS OF NOISE POLLUTION ON WHALE MIGRATION. "We have developed a model to explore the impact of ocean noise on whale migration routes, where higher ambient noise (i) reduces whale communication space, (ii) generates an avoidance response when sufficiently loud, and (iii) lowers inherent navigation information. Each mechanism can lengthen the journey time, and certain scenarios may even lead to failed migration. As such, the energetic cost of migrating in the current ocean soundscape is expected to be higher than in a pristine soundscape. Notably, though, each mechanism has a subtly different impact: it is not simply three different forms of slower migration. Rather, diminished communication space leads to greater solitude and slower migration as collective navigation benefits are eroded. Under a loss of information there is increased confusion, leading to off-course drifting and greater susceptibility to ocean currents. Finally, loud noises lead to a strong noise avoidance response and routes that become blocked, and hence migration may fail." SCIENTIFIC REFERENCE Johnston, S.T. & Painter, K.J. (2024). Avoidance, confusion or solitude? Modelling how noise pollution affects whale migration. Movement Ecology 12: 17 (First published online: 19 February 2024). https://lnkd.in/gxHX-t8u.

Blue Whales Are Falling Silent: A Climate and Noise Pollution Warning Introduction: Ocean Giants Losing Their Voice A six-year study off California’s coast has revealed a troubling phenomenon—blue whales, the largest and typically most vocal creatures in the ocean, are becoming increasingly silent. Scientists believe this shift signals deeper ecological distress caused by marine heat waves and escalating underwater noise pollution. Key Details: • Study Findings • Researchers used a 32-mile-long underwater cable with a hydrophone to monitor ocean sounds over several years. • Data showed a notable decrease in whale vocalizations, suggesting disruptions in communication and behavior. • Environmental Stressors • Marine heat waves are altering whale habitats and food availability, impacting migration and mating behaviors. • Noise pollution from shipping, industrial activity, and naval operations interferes with whales’ long-distance acoustic signals. • Implications for Marine Ecosystems • Whale songs are essential for navigation, feeding coordination, and reproduction. • Reduced vocal activity may signal broader ecological stress, potentially affecting the entire marine food chain. • Conservation and Monitoring Efforts • Scientists emphasize the importance of acoustic monitoring to track ocean health and biodiversity. • Mitigating noise pollution and addressing climate impacts could help restore marine soundscapes and whale populations. Conclusion: Listening to Save the Oceans The eerie silence of blue whales serves as a warning that human activity and climate change are profoundly disrupting marine ecosystems. Protecting these ocean giants may begin with understanding—and preserving—the sounds of the sea itself. https://lnkd.in/gEmHdXZy

Jenn Thornhill Verma shares evidence that the whales and other marine animals are particularly vulnerable to sound is driving calls for quieter vessels, in her article in the Guardian today. The delicate clicks and whistles of narwhals carry through Tasiujaq, locally known as Eclipse Sound, at the eastern Arctic entrance of the Northwest Passage. A hydrophone in this shipping corridor off Baffin Island, Nunavut, captures their calls as the tusked whales navigate their autumn migration route to northern Baffin Bay. But as the Nordic Odyssey, a 225-metre ice-class bulk carrier servicing the nearby iron ore mine, approaches, its low engine rumble gives way to a wall of sound created by millions of collapsing bubbles from its propeller. The narwhals’ acoustic signals, evolved for one of Earth’s quietest environments, fall silent. “Narwhals stop calling or move away from approaching vessels when they hear them,” says Alexander James Ootoowak, an Inuk hunter from Pond Inlet and field technician with the research team that deployed the hydrophone to study these acoustic overlaps. The research, carried out in 2023 and published this year, adds to mounting evidence that underwater radiated noise – sound energy that ships emit through their hulls, propellers and machinery – is disrupting marine life. As the crescendo grows, so too do calls to quiet the seas by designing less-noisy ships. Michelle Sanders, director general of the Innovation Center at Transport Canada in Ottawa, says: “We need to bring everybody together to work toward a solution that will reduce the sound in our ocean to protect marine species, regardless of where the ships are operating.” +++ Whilst several comments on one of my recent posts about a new generation of sailing vessels were full of ridicule and laughter, I persist in supporting a quieter ocean. Noise pollution is like any kind of pollution. And it upsets and harms the animals. Once more, we humans can be so unconscious of anyone other than our own business and freight and trade. These animals become yet another externality in the cycle of extractive capitalism and industry. This research explains why we need to change our ways. Sorry, (well, not sorry at all, in fact), but we will just have to go slower. This is part of being aware, of being in relation with the more-than-human. It is challenging for the dominant mindset but happily many are realising, and many are also wanting to change their ways, and to show more respectful behaviour when in presence of animals. The original research in Nature "Narwhal acoustic presence in Eclipse Sound, Nunavut: relationships with sea ice and responses to ships" can be read here: https://lnkd.in/eUwb9rvG This is a hugely important issue, and affects marine animals who live close to shipping lanes all over the world. https://lnkd.in/e5iewv4X

The environmental impacts of offshore wind. Offshore renewables are part of the transition to clean energy, but must be developed in a nature- and people-inclusive way. As offshore renewable energy is projected to increase exponentially, concerns are growing over the deteriorating health of the ocean, which is already threatened by climate change and human activities. A non-exhaustive list of the environmental impacts of offshore wind energy during different stages of its lifecycle, such as construction, operation, and maintenance. - Collision risks: Wind turbines are major collision risks for birds, bats and marine mammals. Wind farms may also disrupt migratory routes and affect animal behaviour, leading to the loss of foraging and resting habitats. - Pile driving noise: The impulsive noise generated by pile driving in the construction phase has received the most attention regarding its potential negative effects on marine life. - Service vessel noise: Service vessels generate a largely unknown amount of continuous noise to the surrounding ecosystem. This noise level should be assessed and monitored at every wind farm. - Underwater noise impacts: The construction, operation and maintenance of wind farms generates underwater noise. This noise can be both continuous and impulsive, and may cause physical injuries or impact behaviour in many species including birds, marine mammals, fish and sharks as well as invertebrates. - Electromagnetic fields from cables: The cables connecting wind turbines to land create electromagnetic fields that can affect the behaviour of species with electroreceptors such as sharks, rays, sturgeons and lampreys, and of species with a significant migratory phase. - Artificial reef effects: Turbine foundations can act as artificial reefs, potentially attracting marine life and boosting biodiversity. However, the introduction of these structures can also displace and convert habitats, attracting invasive species, and impacting ecosystems and the food web. When installing offshore wind turbines, it is crucial to consider the characteristics of native habitats to restore their original features and avoid habitat conversion, the introduction of alien species, and the resulting impacts on the food web. Longer term benefits of artificial reefs depend on wind farms are decommissioned. - Spawning and nursing recovery: Offshore wind farms can help re-establish or recover key spawning and nursing areas and may boost the recovery of benthic communities previously affected by industrial fishing and bottom-contacting gear. - Hydrodynamic and nutrient impacts: Underwater structures can alter currents and the stratification and mixing of the water column, affect nutrient concentration and seabed habitats. These changes can impact primary production, the process through which marine microorganisms create organic matter from non-organic matter, and which is at the basis of the oceanic food web. Seas-at-risk.org