Altered Ocean Acoustics: The Costs of Green Energy

Altered Ocean Acoustics: The Costs of Green Energy

By Colette Sawyer, Age 16 

All cetaceans in the world rely on sound for communication and survival in the ocean. As little light penetrates the profound depths of our oceans, reliance on sight is of little value for ocean mammals, rather sophisticated adaptations have evolved to utilize sound. Sound waves that can travel long distances in the ocean can help marine creatures navigate the waters, communicate with each other, detect predators, forage and reproduce.  This soundscape, however, is changing. A surge in anthropogenic noise, emanating from human activities such as oil rigs and offshore wind farms, altered geophysical sources such as melting icebergs, and decreases in sound-generating animals change the ocean’s natural acoustic environment threatening the survival of many marine mammals. (1)

Anthropogenic noise can have a significant impact on marine mammals even in our backyard. New York State has promised to achieve a goal of full reliance on green energy by 2040. In order to do so, it has begun to build offshore wind farms. (2) The management of a successful offshore energy plant involves three main phases: construction, post-construction, and decommissioning. Construction activities require extensive boat traffic and pile driving to secure the wind turbines, substantially elevating anthropogenic noise levels in the environment. Operational wind turbines generate constant noise while their cables emit electromagnetic sound waves. Any maintenance activities introduce additional boat traffic. Decommissioning, the process of removing turbines, likewise generates abrupt and constant noise that disrupts the soundscape. In addition to increases in anthropogenic noise from construction, maintenance and decommissioning of wind farms, many of these wind farms are located in the middle of endangered species habitats such as that of the Right Whale (4).  

Indeed, this summer many whales were found beached on our shores. Conservationists wondered whether the construction of these wind farms not only altered the soundscape of the oceans but may have had detrimental consequences on the ability of these whales to navigate the waters. (3) Often research on the exact cause of death of beached whales is difficult to do and ongoing concerns need to be evaluated. It is known that right whales communicate daily using calls at a specific frequency and many studies have shown that the noise generated by boat traffic and wind turbines are at the same frequency as these whale’s calls, masking calls made by the whales themselves. (5) Other scientists have shown that constant background noise can impact migration routes, leading to hearing damage and altered stress behaviors in mammals. (5) 

According to the Marine Mammal Protection Act of 1972 governments must try “to prevent marine mammal species and population stocks from declining beyond the point where they cease to be significant functioning elements of the ecosystems of which they are a part.” (6). Given the importance of sound for the survival of marine mammals, any changes to the ‘soundscape’ of our oceans should be researched and prioritized in protecting endangered species. Despite evidence that anthropogenic noise interferes with whale communication, there is a scarcity of studies defining the specific behavioral changes resulting from these disruptions.  Wind energy companies contend that skepticism about the benefits of wind farms comes from politicians rather than scientists. It is therefore important that scientists have their voices heard as we try to combat the effects of climate change by showing that we are committed to research examining how these interventions will impact the natural habitat of marine mammals, especially those already endangered, before imposing interventions that can cause irrevocable damage. 

Duarte et al.The soundscape of the Anthropocene ocean. Science 371, eaba4658 (2021). DOI: 10.1126/science.aba4658

https://www.nyserda.ny.gov/All-Programs/Offshore-Wind/Focus-Areas/Climate-Change-and-Offshore-Wind 

https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/frequent-questions-offshore-wind-and-whales 

https://www.boem.gov/environment/protecting-north-atlantic-right-whales-during-offshore-wind-energy-development

De Vere, Lilly, Frick. Anthropogenic Impacts on the Welfare of Wild Marine Mammals. Aquatic Mammals 2018, 44(2), 150-180, DOI 10.1578/AM.44.2.2018.150

Marine Mammal Protection Act Policies, Guidance, and Regulations | NOAA Fisheries

Photograph taken by Colette Sawyer, July 2023