Ørsted is planning an attempt to support coral reefs by growing corals on offshore wind turbine foundations. Together with Taiwanese partners, the company will test the concept in the tropical waters of Taiwan this summer.The aims are to determine whether corals can be successfully grown on offshore wind turbine foundations and to evaluate the potential positive biodiversity impact of scaling up the initiative.
The ReCoral by Ørsted project aims to implement a non-invasive approach for collecting surplus indigenous coral spawn as it washes ashore and for growing healthy coral colonies on the foundations of nearby offshore wind turbines. Increased surface temperatures in shallow waters can lead to coral bleaching. At offshore wind farm locations further offshore, temperatures are more stable due to vertical mixing in the water column, preventing extreme temperature increases.
The idea behind ReCoral is that the relatively stable water temperatures at offshore wind farm locations will limit the risk of coral bleaching and allow healthy corals to grow on wind turbine foundations. Corals will be grown close to the water's surface to ensure sufficient sunlight.
In 2020, biologists and marine specialists in Ørsted teamed up with private and academic coral experts to mature and test the concept. In 2021, the ReCoral team successfully grew juvenile corals on underwater steel and concrete substrates at a quayside test facility for the first time. In June this year, the offshore proof-of-concept trial will begin at the Greater Changhua offshore wind farms in Taiwan to test the concept in open waters on four separate wind turbine foundations.
Ørsted collaborates with the Penghu Marine Biology Research Center in Taiwan, and together they have developed a non-invasive methodology for coral seeding, in vitro fertilisation, larvae transport, and larvae attachment to wind turbine foundations. Rather than removing anything from existing coral ecosystems, ReCoral’s non-invasive approach relies on the collection of surplus coral egg bundles that wash up on shorelines and would not otherwise survive.
If the proof-of-concept trial is successful, Ørsted will explore opportunities for scaling up the initiative. The ReCoral concept could be applied to offshore foundations of any kind in tropical waters around the world. Ørsted will share learnings and the techniques the ReCoral team develops with the broader coral conservation community, and with other wind farm developers.