Coexistence with Marine Life

No. The offshore wind industry is subject to the highest levels of protection for whales and other marine mammals. Every aspect of our surveys, construction, and operations are reviewed by multiple local, state, and federal agencies to ensure protected species remain unharmed. We are also subject to protective conditions, including vessel speed limitations, time of year restrictions for construction activities, and having dedicated observers onboard our vessels. 

As noted by NOAA in an effort to combat misinformation, there is no evidence linking offshore wind activity to whale strandings. In fact, offshore wind farms have a crucial role to play in protecting whales by fighting climate change, which has notably altered whale feeding and migration patterns. These new patterns put whales at increased risk of colliding with vessels, one of the leading causes of large whale deaths. 

To stop ships from crossing whales, Ørsted is funding the WhaleAlert app. This application relays close to real-time information on whale locations to commercial and recreational vessel operators, helping vessels avoid collisions. In parallel, we’re making industry-leading investments in new technologies to improve whale detection and monitoring and strengthen marine mammal protections across maritime industries. 

While offshore activities do produce noise, protective measures are employed at all stages of siting and construction to minimize noise and protect marine wildlife. 

At the siting stage, technologies used for High Resolution Geophysical (HTG) surveys produce little noise. Few HRG sound sources used in offshore wind surveys operate at frequencies even detectable by marine mammals. While HRG sources are in use, Ørsted employs trained observers onboard our vessels, who continuously monitor for the presence of marine mammals. If marine mammals are detected in the vicinity of survey activity, HRG sound sources detectable to marine mammals are immediately shut down. 

This is done out of an abundance of caution. Federal agencies have already determined that no injury to marine mammals or other protected species is expected from HRG sources, as the sound produced by this equipment has been shown to diminish rapidly with distance. 

At the construction phase, Ørsted uses state-of-the-art noise abatement and mitigation technologies to reduce noise that would otherwise disturb underwater life. Our offshore projects employ technologies like double bubble curtains and hydrosound dampeners to mitigate underwater noise. Our experts are also working closely with innovators developing new technologies that will further reduce noise during monopile installation. 

We employ a variety of proven mitigation techniques and technologies to ensure marine mammals are protected during offshore wind farm construction. These include: 

• Dedicated observers to keep a lookout for whales, dolphins, sea turtles, and other marine life. If any marine animals are spotted within certain siting or construction zones, work is immediately halted. 

• Acoustic monitoring technology. This enables us to listen for approaching marine mammals, alerting us to their presence even in low-visibility conditions. If marine mammals are detected, work is halted to ensure their safety. 

• Clearance and shutdown zones. Clearance zones are specific areas which must be free of marine mammals before activities start. Shutdown zones are areas where siting and construction activities must be immediately halted if marine mammals enter. 

No. Vessels used to build offshore wind farms work in relatively small construction areas, limiting their potential contact with marine wildlife. All vessels must comply with speed restrictions and noise reduction regulations, and are required to have observers onboard looking out for marine creatures. 

When Ørsted uses vessels to build offshore wind farms, we take extensive precautions to minimize their impact on marine life. We comply with all requirements noted above and coordinate extensively with other maritime stakeholders, including local mariners and the U.S. Coast Guard. 

As part of our pre-construction activities, Ørsted undertakes a series of offshore surveys to acquire information required for state and federal permits and help inform project design. This process is called offshore site investigation. 

One kind of offshore site investigation we conduct is High-Resolution Geophysical (HRG) surveys, which allow us to map the seafloor and subsurface geology. HRG surveys use a combination of acoustic (i.e., sound-producing) equipment and passive sensors that do not produce sound. These surveys make use of the same equipment used by oceanographers to map the world’s oceans, and by search and rescue teams to locate downed ships and aircrafts. The same equipment is also used by the U.S. Army Corps of Engineers to locate sand resources to replace sand on public beaches. 

Both offshore wind and oil and gas conduct HRG surveys using some common equipment. However, technologies used in offshore wind produce much lower energy (in the form of underwater noise) and travel far shorter distances from the survey vessel than those used by the oil and gas industry for deep-sea exploration. Oil and gas exploration requires the use of powerful sound sources, such as air guns, to conduct seismic testing and seismic blasting. These sound sources and techniques are not used in HRG surveys for offshore wind.