´óÏó´«Ã½

During construction, underwater noise (such as from pile driving and vessel traffic) could disrupt whale and dolphin echolocation. Increased vessel traffic may raise the risk of collisions with slow-moving species like turtles. And the water quality may suffer if it¡¯s not managed correctly.

Common mitigation measures include restricting vessel speeds, employing marine mammal observers, and using ¡®bubble curtains¡¯. The bubble curtains create a barrier of air bubbles to reduce underwater noise and protect sensitive marine species. The effects of any seabed disturbance can be modelled and tested to help maintain water quality.

Once operational, we will face other challenges. Sometimes, it¡¯s the presence of the structures themselves¡ªand this is particularly true for floating turbines. They may introduce a risk of snagging marine debris, which can then become a risk of entanglement for marine life (this is known as ¡®secondary entanglement¡¯). Also, electromagnetic fields from subsea cables could alter the behaviour of certain fish and invertebrates. In the skies, seabirds and even bats face collision risks with turbine blades.

But new technology is helping us out. Real-time monitoring and smart wind farm curtailment systems¡ªlike our EchoPITCH? tool¡ªare keeping bats and avifauna safe by changing how the turbines work based on live acoustic and environmental data.

Turning offshore wind farms in Australia into artificial reefs

Many offshore wind farms are located on vast sandy seabeds. These seabeds may have sparse appearance, but they are habitats for a range of burrowing invertebrates and demersal fish. However, they typically offer fewer hard surfaces or complex structures for marine life to colonise above the seabed.

When we put hard structures like wind turbine foundations in the ocean, they give marine organisms new places to attach to and grow. Epibenthic species like barnacles, mussels, and tube worms quickly colonise these structures. Anemones, ascidians, soft corals, sponges, and encrusting algae commonly settle at deeper levels.

This added habitat complexity attracts a wide range of marine species. That leads to increased biodiversity. And it also provides shelter and food sources for fish, crabs, and other mobile organisms. Over time, larger predators such as rays, sharks, and even marine mammals start to live around these artificial reefs. This makes the ocean environment more diverse and connected with lots of species living together.

These transformations happen quickly. In the US, two offshore wind turbines off the coast of Virginia, installed as part of a pilot project by Dominion Energy in 2020, became vibrant reef systems within just five years. Within six months, the company¡¯s scientists reported that algae and mussels had already begun colonising the underwater structures. Now, schools of fish gather around their foundations, and sea turtles and sunfish swim by.

Exploring the potential of offshore wind farms as artificial reefs

We don¡¯t have to look far for proof that artificial reefs work. Around the world, decommissioned oil rigs, sunken ships, and purpose-built structures have transformed into complex marine ecosystems for various purposes.

Take the oil rigs in the Gulf of Mexico. In 1979, the US set up its Rigs-to-Reefs program. Since then, more than 600 oil rigs have been left in place. These structures provide acres of habitat for hundreds of marine species and homes for 12,000 to 14,000 fish, according to a study by the Coastal Marine Institute.

Closer to home, a scuttled Royal Australian Navy warship (HMAS Adelaide) off the Central Coast of New South Wales has become an artificial reef home to a wide diversity of marine life. It attracts divers from all around the world. We can¡¯t simply leave these structures in situ¡ªthey must be thoroughly cleaned and hazards removed before they can be used as artificial reefs.

Not every structure planted in the ocean depths will spawn a new marine ecosystem¡ªdesign matters. Marine life prefers rough surfaces, crevices, and overhangs that mimic the complex structures of natural reefs. Adding scour protection around turbine bases or using reef plates or balls around the foundations are ways to boost their ecological potential.

But building artificial reefs isn't just about attracting marine life. It¡¯s about attracting the right marine life. Thoughtful design can enhance habitat for native species while deterring invasive ones. Designers can tailor material selection, surface texture, and structural complexity. All of those choices can help support biodiversity goals. And 3D printing could allow for further customisation to meet specific ecological objectives, from attracting certain fish to promoting coral growth.?

How could offshore wind farms in Australia support sustainable fisheries?

Many local fisheries are cautious about offshore wind development. That¡¯s understandable, given that new infrastructure often brings with it more fishing restrictions. But research suggests offshore wind farms could boost fish stocks.

Many offshore wind farms function as marine sanctuaries, either officially or because there is limited human activity. Restrictions on fishing and other disruptive practices create safe areas for fish to breed and feed. And this can lead to more fish, particularly in areas where there were few before.

Take the Borssele 1 & 2 wind farm in the North Sea. Wageningen Marine Research found endangered Atlantic cod thriving around offshore wind turbines, taking advantage of the artificial reef structures.

In Australia, the Bass Strait has strong potential for combining offshore wind and fish farming, according to research by Griffith University. This shared use of space could cut costs by using the same infrastructure, reduce pressure on the environment, and create new jobs and investment in the blue economy.

Good planning and early engagement with the fishing industry are important to offshore wind farms in Australia. Working alongside commercial fisheries could help create healthier and more sustainable fish populations.

Planning for the long-term sustainability of offshore wind farms in Australia

We need to monitor how marine life interacts with these structures over time. It¡¯s also important to plan for what happens when the wind farms reach the end of their life, so they can keep supporting the environment into the future.

Offshore wind farm operators must plan for the end of a wind farm¡¯s life from the beginning. That includes developing a decommissioning plan. This generally outlines how turbines will be dismantled, removed, and recycled or repowered. A justification would need to be provided to leave them in place (or partially remove them) so they can be safely maintained as artificial reefs for marine life.

We can learn from existing programs. The Rigs-to-Reefs program in the US has repurposed old oil platforms¡ªstructures similar in scale and complexity to offshore wind turbines¡ªinto artificial reefs. In Australia, a study found that parts of a decommissioned refinery near Adelaide were valuable as a marine habitat, providing a home for Australian fur seals.

Designing offshore wind farms in Australia for lasting environmental benefits

As we look to build offshore wind farms in Australia, we can produce clean energy and also support marine life. Around the world, we¡¯ve seen how smart designs can deliver both.

But to get these benefits here, we need careful planning and strong collaboration between communities, government, and industry. If we make the right decisions early, offshore wind farms in Australia can create lasting benefits for our environment¡ªboth above and below sea level.