Virginia’s First Offshore Wind Turbines Become a Heaven for Marine Life | State and region news
Katherine Hafner The (Norfolk) Virginian-Pilot
In the Atlantic, about 27 miles off the coast of Virginia Beach, schools of fish congregate around what looks like a large cylinder covered in algae. The mussels flourish on the structure. Even the occasional sea turtle or the giant ocean sunfish pays a visit.
The source of this lively underwater scene is somewhat improbable: a wind turbine.
Dominion Energy’s first two offshore turbines, currently used only for research, have become a haven for marine life.
âIt’s just amazing the fish ecosystem that develops around these turbines,â said Scott Lawton, Environmental Technical Advisor for Dominion.
The spire structures stretch 600 feet high, eclipsing the height of the Washington Monument. But the turbine’s steel foundation also extends underwater, about 120 feet.
Dominion’s lease area is roughly the size of 85,000 football fields. There are only two pilot wind turbines, but the company aims to build 180 more for a commercial wind farm by 2026. It needs several state and federal approvals first.
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The turbines started operating last October. As part of the site survey, Dominion took underwater videos of the steel foundation, which is also surrounded by rip-rap style rubble on its base – called scour protection.
The videos were taken about six months after the project started and then again in September. The change in marine life has been dramatic, said Mitchell Jabs, an environmental specialist from the Dominion.
Mussels, seaweed, mahi, sea bass, baitfish and others surround the structure or settle directly there. It’s not just the outside of the foundation, Jabs said. Holes in the turbine to release pressure and allow water to rise and fall also allowed marine life to pass through or reside within.
They âall hang around and feed on whatever pushes on the turbines,â she said.
Scientists off the Scandinavian coast have seen the foundations of underwater turbines gradually transform into artificial reefs, attracting molluscs and small fish that feed on plankton, according to the German news channel Deutsche Welle. The effect went “to the top of the food chain for larger fish, seals and dolphins,” according to the channel.
Off the coast of California, a the old oil rig is home to a thriving reef.
Marine animals such as mussels that require hard surfaces would not normally be in many areas of the open ocean, although some find rocky bottoms to attach themselves to, said Mark Luckenbach, associate dean of research and of the advisory service at the Virginia Institute of Marine. Science.
Foundations allow these organizations to live. The fish are then attracted to the food source.
There is evidence that structured reefs can not only attract fish, but increase overall populations, he said. But that remains to be seen.
The Institute of Marine Sciences is working with Dominion to partner or design possible scientific studies at the site, including monitoring the effects of the turbines on local fisheries, Luckenbach said.
The construction phase of wind farms can be harmful to marine life, causing significant noise and vibration. Lawton said Dominion uses a “double bubble curtain” to drive the foundation into the seabed to reduce sound traveling through the water.
Meanwhile, they are also looking for wild animals above the water: birds and bats that might collide with the blades.
Due to their distance from the shore – about two hours by boat – the turbines do not see a particularly high density of birds. But there is.
So far, the company has primarily documented seabirds in the area, including the Northern Gannet, through routine boat surveys. Most of the environmental concerns are with red knots and piping plovers, said Matt Overton, the Dominion’s biology consultant. The company did not see them.
Acoustic microphones and video surveillance on the turbines are also believed to help capture bird and bat activity. The company said it had seen no evidence of a strike.
The risk is small, but it still exists, Overton said. Bats have been seen on ships far out in the ocean, and some birds migrate from South America to the Atlantic.
The energy company will have to carry out several environmental impact studies as part of the next authorization process.
When authorities begin construction of the commercial turbines, they will have to plan for another marine mammal: the endangered North Atlantic right whale.