The Potential Impact of Floating Wind Farms on Marine Ecosystems

There’s not a lot of data on the underwater ecosystems developing on and under floating wind structures; there’s just not that many of these farms installed yet. A recent study by researchers in Scotland set out to analyze what data there is and to hypothesize about what the potential positive and negative effects might be for marine life.

It’s potentially important because floating offshore wind is being developed on highly productive shelf seas. They cover approximately 9% of the global ocean area but account for around 16% of global ocean primary production and support 90% of the world’s fish catches.

Wind farm structures can create new habitats at a regional scale and throughout the water column, potentially benefiting a range of pelagic and benthic species. Studies of oil and gas platforms have found artificial reef effects that extend out around 800 meters, and floating structures are known to be used as fish aggregating devices.

The Risks and Traps

Different platform designs offer different amounts of surface available for colonization, different structural complexity, and different types of movement. However, there could be a trap. Ecological traps occur when species are drawn to a site for positive reasons such as feeding, shelter, or breeding but end up experiencing negative outcomes.

The researchers list three main types of entanglement to consider at floating offshore wind farms:

• Primary entanglement: an organism becomes directly entangled with a structure
• Secondary entanglement: debris such as ghost fishing gear becomes caught on a structure and subsequently traps an organism
• Tertiary entanglement: an organism already entangled in debris then becomes caught on the structure

The researchers evaluated published studies from two sites with five and one site with 11 turbines and found mixed results regarding the biota developing on them. More data is needed to fully understand the impact of floating wind farms on marine ecosystems.

Future Opportunities

That opportunity for more data may be coming. This week, Norway opened a bidding round for three floating wind areas, and California-based Aikido Technologies signed an agreement with Marine Energy Test Centre (METCentre) in Haugesund, Norway, to deploy one of the largest floating wind platforms deployed to date.

The March issue of Marine Technology Reporter looks at how small and agile underwater robots can, among other functions, serve as non-invasive tools for assessing marine life around offshore installations, helping to inform ecosystem-based management approaches.