Offshore wind farms may meet our energy demands but will harm marine life if steps are not taken, warn scientists
With Europe embracing offshore wind farms, it is time for the US to follow suit, say experts. An estimated $70 billion offshore wind business is expected to take flight in the US by 2030.
While this step is crucial in addressing climate change issues, going forward without considering marine life could threaten their existence, warn scientists.
"Offshore wind farms are part of the suite of tools being used to reduce our reliance on fossil fuels and as such, they are an essential part of efforts to mitigate climate change," first author Andrew Wright, an ocean and ecosystem scientist at the Natural Sciences and Engineering Research Council of Canada, tells MEA WorldWide (MEAWW).
"However, in certain areas, their installation may harm or displace marine life in ways that need to be balanced against the benefits of the technology," Wright adds.
Organisms that stand to lose the most are dolphins and whales that use echolocation to navigate and hunt. Further, sounds from wind farms can cause distress to marine life.
"Think about what it'd be like to live next to all those jackhammers and power drills. I don't think a lot of people appreciate that when it's offshore, it may be silent for humans, but if they stick their head underwater where the animals live, it is much, much louder," shares Wright.
That is not the only danger. Marine animals like dolphins and porpoises run the risk of being hit by the turning blades of wind turbines, causing blunt-force trauma. This is similar to onshore wind farms that hurt birds and bats.
There has been a lot of interest in offshore wind farms. Standing 200 m tall, they are much bigger than their land-based counterparts — and far more efficient. They have the potential of generating more than 2,000 GW of capacity per year — nearly double the nation's current electricity use.
The only such wind farm in the US is off Block Island, Rhode Island, which supplies 30 MW of electricity to a tiny community of about a thousand residents. The New York Energy Research and Development Authority has awarded two large contracts for offshore wind. And there are more in the pipeline.
"The installation of anything on the seafloor will have impacts on the animals that live there — sometimes good, and sometimes bad, " Wright shares.
Some marine life make these wind farms their home. For instance, according to an earlier study, the North Sea, where most of the European farms are being built, is dominated by blue mussels.
These mussels, in turn, are also a food source for other marine animals, such as fish and crabs, and this has the potential to significantly alter the food web. While windfarm can support mussels and other marine life, these organisms will end up replacing other organisms, says Wright.
While the effects of wind farms are well-studied in harbor porpoises and seals in European waters, scientists have to still figure out how they impact other species, as the wind farms continue to expand, explains Wright.
What is worse, constructing these farms produce a lot of noise. For example, the Taiwanese white dolphin, an endangered species, is finding it hard to escape the construction noise in their increasingly shrinking habitat. These dolphins are more likely to suffer from hearing loss and chronic stress, says the study.
The trauma to marine life does not end here. These wind farms can produce noise even after construction. While some technologies are relatively quiet, others can cause low pitch sounds that echo through the water, and disturb animals that rely on sounds to explore the world.
The solution, according to Wright, is not finding alternatives to wind farms, but instead tailoring the designs of the equipment to local areas after considering the marine life that are present.
"There are also opportunities to relocate existing industries that may be problematic for different marine species, such as fishing, shipping or oil exploration, to other areas to accommodate a wind farm," Wright says.
"This may present a means to reduce the overall pressure on, for example, an endangered dolphin species, despite adding a new activity to the area," Wright adds. The study has been published in Cell Press.