Offshore wind development is rapidly ramping up in United States waters to meet renewable energy goals and reduce global dependence on fossil fuels. Offshore wind speeds tend to be higher and more consistent than over land, exponentially increasing the amount of power generated—the federal government aims to establish 30 gigawatts of new offshore wind energy by 2030. But with several endangered large whale species and a multitude of other protected marine species frequenting these same waters, understanding the potential consequences of construction and operation activities is essential to advancing responsible offshore wind development.
Marine mammals are highly dependent on their hearing systems for orientation, hunting, and communication among individuals. Whales, dolphins, and bats above water, use reflected sound, or echolocation, for navigation—these animals produce sound waves bounced off other objects to determine distance, direction, speed, density, and size. Sound travels about four times faster underwater than through air, and it can travel thousands of miles without the signal losing considerable energy.
Man-made noise produced when constructing and operating an offshore wind farm could make it impossible for a dolphin or whale to acoustically interpret the environment, potentially leading to collisions, disorientation, difficulty finding food, or displacement from feeding grounds. The Marine Mammal Commission supports the establishment of offshore renewable energy, but calls for any new proposed project to proceed in a “thoughtful and deliberate manner.”
A thorough and scientific approach to understanding interactions between marine life, habitat, and offshore energy infrastructure and development activities, as well as potential impacts, must be developed to protect marine mammals, as well as the overall health of the ocean ecosystem. This includes tracking migration patterns of species ahead of site development and monitoring underwater sound levels monitored during construction. Once construction is complete, marine mammal surveys continue, and the data is compared to data collected pre-construction to identify any changes in species presence, abundance, or behavior.
Monitoring marine mammals has traditionally been very difficult, primarily conducted by certified and trained Protected Species Observers (PSOs) performing visual surveys from ships and aircraft, which are time-consuming and unreliable. More modern methods use hydrophones towed behind a ship or attached to a stationary platform deployed by a ship and tagging individuals with satellite transmitters. However, all of these methods require a costly, noise-producing, diesel-burning research ship.
North Atlantic right whales, which live almost exclusively along the east coast of the US and Canada, are one of the world’s most endangered large whale species.
Saildrone uncrewed surface vehicles (USVs) represent a more effective, cost-efficient, and environmentally friendly alternative to traditional ship and aircraft-based marine mammal monitoring. Saildrone USVs leverage machine learning (ML) technology combined with a 360° camera system and/or passive acoustics to detect, classify, and pinpoint the location of marine mammals. Deploying uncrewed vehicles offshore allows PSOs to monitor from shore-based locations, reducing associated health, safety, and environmental risks.
While the most significant environmental concern related to offshore wind developments is the impacts of sound on marine mammals, other major concerns include the risk of collisions with turbines for seabirds and bats, increased vessel traffic, changes to underwater habitats and food webs, and the release of contaminants into the water column from seabed sediments.
Saildrone’s three classes of USV—the 23-foot Explorer, 33-foot Voyager, and 65-foot Surveyor—work together to autonomously collect ocean data throughout the life cycle of an offshore wind farm, with a low or zero operational carbon footprint. Meteorological and oceanographic sensors deliver persistent year-round ecosystem monitoring above and below the sea surface. And similar to how they monitor underwater species, Saildrone USVs can detect the presence of birds and bats as well. They can be equipped with echo sounders to measure fish biomass and provide International Hydrographic Organization-compliant ocean mapping down to 23,000 feet, and also carry Acoustic Doppler Current Profilers for measuring the speed and direction of ocean currents or an ASVCO2 system for carbon monitoring.
The impressive capabilities of Saildrone’s autonomous vehicles have been proven in numerous operational missions for science, ocean mapping, and maritime security, covering almost 1,000,000 nautical miles from the Arctic to the Antarctic. The Saildrone fleet has logged more than 20,000 days at sea in some of the most extreme weather conditions on the planet.
Marine mammals play an important role in the food web as both predator and prey and help ensure a balance in the ocean’s ecosystem. The US government’s ambitious goal for new offshore wind developments would support 77,000 jobs, power 10 million homes, and cut 78 million metric tons in carbon emissions. Done correctly, comprehensive, high-quality marine mammal surveys throughout all phases of wind farm development will accelerate an important global shift toward renewable energy sources while ensuring the health, safety, and well-being of our oceans and their inhabitants.
Learn more about Saildrone’s Offshore Wind Solutions.
Helen Bailey, Kate L. Brookes, and Paul M. Thompson, “Assessing Environmental Impacts of Offshore Wind Farms: Lessons Learned and Recommendations for the Future,” Aquatic. Biosystems, vol. 10, 8, September 14, 2014, doi:10.1186/2046-9063-10-8
Jon Hurdle, “Can Offshore Wind Coexist with Endangered Whales?” NJ Spotlight News, February 10, 2022
Peter Madsen, Magnus Wahlberg, Jakob Tougaard, Klaus Lucke, and Peter Tyack, “Wind Turbine Underwater Noise and Marine Mammals: Implications of Current Knowledge and Data Needs,” Marine Ecology Progress Series, vol. 309:279-295, March 2006, doi: 10.3354/meps309279
Department of Energy, “Energy Secretary Granholm Announces Ambitious New 30GW Offshore Wind Deployment Target by 2030,” press release, energy.gov, March 29, 2021
European Wind Energy Association, “Impacts on Marine Mammals and Sea Birds,” webpage, wind-energy-the-facts.org, accessed September 1, 2022
Marine Mammal Commission, “Renewable Energy Development and Marine Mammals,” webpage, mmc.gov, accessed August 24, 2021
Office of Energy Efficiency and Renewable Energy, “Offshore Wind Research and Development,” webpage, energy.gov, accessed August 29, 2022