Offshore Wind Energy is a Breeze: Environmental & Wildlife Impacts

By Chloe Taylor, Katrina Vaitkus, Zachary Felch, Justin Stacey, Miranda Mlilo, Amanda Speciale, Katie DeVoss

Chloe Taylor, Katrina Vaitkus, Zachary Felch, Justin Stacey, Miranda Mlilo, Amanda Speciale, Katie DeVoss

Who we are:
We are a group of University of Maryland students majoring in Environmental Science and Policy. For our senior capstone project, we are researching the impact of offshore wind energy to help CCAN prepare for the upcoming public comment period for the proposed Ocean City US Wind Project. We will be creating a series of blog posts to provide information about different aspects of offshore wind and its impacts on greenhouse gas emissions, the economy, and wildlife. This is the last of our three part series.

Although offshore wind is relatively new technology, there is significant evidence proving that offshore wind farms do have a positive impact on the local environment. The negative impacts caused by offshore wind farms are short-lived, as seen at multiple European offshore wind farms such as Horns Rev, Nysted, and Egmond aan Zee. Many scientists currently studying the environmental impacts of offshore wind have found that there is a net positive environmental effect resulting from the existence of these farms.


Environmental Impacts

The development of the offshore wind farm in Ocean City, Maryland will cause some immediate negative impacts from physical disturbance of the local habitat as well as noise pollution both above and below the surface of the water. However, multiple studies conducted on several active European offshore wind farms (Offshore Wind Farm Egmond aan Zee, Horns Rev) have shown that most, or all, of these negative side effects subside over time, eventually becoming negligible. These studies have also shown that there are many positive environmental impacts which occur as a result of the introduction of the wind farm into the ecosystem. These can include, but are not limited to, creation of habitat for wildlife species, increased total biomass, and increased biodiversity.

Although there will be significant modification of the local environment, this will create room for growth in both species richness and diversity. Sites typically chosen for wind farms have naturally occurring sandy sediments. In order to support the wind turbines, large rocks will be introduced to build up the foundation and to increase stability of the monopiles. These large substrates create new habitats for many species of fish and invertebrates. Thus, despite initial disturbance, operating wind farms are capable of supporting many organisms. Benthic communities and aquatic vegetation have found the large substrates around the monopiles to be particularly useful as sites for colonization.

Some images from the National Aeronautics and Space Administration (NASA) Earth Observatory have shown sediment plumes resulting from the flow of water around the monopiles of wind turbines carrying disturbed fine-grained sediments with the current. These plumes can be up to 30 meters wide and several kilometers long. However, increased turbidity in the waters near operating wind farms has proven to subside and to have negligible impacts on local wildlife. After five full years of operation, Egmond aan Zee wind farm in the Netherlands showed zero negative impact on the benthic communities within the wind farm site resulting from increased sediment flow.


Marine Species Impacts

Marine organisms face several negative impacts from the creation of wind farms including increased noise pollution. However, the benefits that come from the creation of the wind farm outweigh the negative effects. The noise levels created by fully operational offshore wind farms have shown minimal long-term disturbance of organisms within the local area, however knowledge on this topic is lacking and requires further study over longer periods of time. However, the most dramatic noise pollution occurs during pile driving, but it is not a long-term impairment. One Dutch study showed an increase in the detection of dolphins inside the wind farm area as opposed to outside sampling sites. This same study also reported the return of seals to the area following completion of construction.

According to a study conducted by the University of Maryland Center for Environmental Science, the noise generated by an active turbine may be audible to marine mammals from just over 40 miles away. Ongoing research explains methods that can be used to significantly reduce the impact of noise on the surrounding environment.

Following the construction of wind farms, each turbine may support marine wildlife on a large scale. Each wind turbine is able to support up to four metric tons of shellfish that attracts other marine wildlife to the area, similarly to that of an artificial reef. The wind farm will then attract a wide range of organisms to the area due to the newly available habitat and resources. The higher abundance of smaller organisms will attract larger predatory organisms to the wind farm and create a healthy marine ecosystem that may not have been as abundant or productive pre-construction.

The increased biodiversity provides marine mammals with high food availability, encouraging them to return to the area in higher abundances than pre-construction. The increase in food availability resulting from the physical structures of the turbines will provide an overall benefit to marine organisms and their ecosystem.


Avian Species Impacts

The proposed wind farm in Ocean City will be positioned in the path of the Atlantic Flyway, a major migration pattern for birds along the east coast of North America. Birds that fly along the Atlantic Flyway may include the bald eagle, golden-winged warbler, and piping plovers. This causes fear that there will be increased bird strikes during the annual migration. There have been several studies to quantify the estimated rate of impact of the proposed wind farm in Ocean City, which has proven to be minimal. In fact, wind farms cause fewer bird deaths than other anthropogenic factors. One of these studies found that, “wind farms and nuclear power stations are responsible each for between 0.3 and 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fueled power stations are responsible for about 5.2 fatalities per GWh.” This data was collected from land based wind farms, where the abundance of birds and bats is much higher than on the coast. As such, the strikes from offshore wind farms would be much lower comparatively to the land farms and other types of energy production. Another study conducted at an offshore wind farm called Horns Rev located in the North Sea found minimal bird collisions with the turbines based on observation and modeling.

Furthermore, few species fly far enough off the coast for the wind farm to interfere with their normal flight pattern. Local bird species who do not necessarily use the Atlantic Flyway for their migration were found to be in higher abundance near the wind farms because of the higher localized biodiversity. Cormorant and seagull populations actually increased in the wind farm area. Additionally, the birds inhabited the area for longer periods of time than previously measured and would nest on the turbines. Birds that are migrating along the Atlantic Flyway are likely to have few strikes and perhaps even use the wind farm for an intermediate point for rest and a source of nutrition. The presence of a wind farm in this area would provide a beneficial site for resting, socialization, and foraging.


Based on findings and information from currently active wind farms, the overall environmental impact of offshore wind in Ocean City will be positive. The area will experience a decrease in carbon emissions resulting from increased biodiversity because of creation of new habitat and food sources, as well as increased total biomass. While wildlife may be negatively affected during construction and servicing of turbines, these effects tend to be short-lived and have shown minimal or no long-term negative impacts on behavior or physiology of species present. Current knowledge of offshore wind has provided a lot of insight into the potential issues which may be faced during construction and implementation, making it possible to anticipate and preemptively act to mitigate any negative effects. Thus, serious environmental harm can be avoided while taking advantage of the benefits of clean energy.