Could fish larvae be disturbed by offshore wind farms?

Fish larvae can travel a long distance from their spawning site to where they grow up, being carried by the ocean currents as well as swimming and orienting using cues from the environment such as sounds and odors. If they are disturbed on this dangerous journey, it can affect where they end up - and thus the chances they have of surviving. “In the worst case, they could end up in a place where there is little food and a lot of predation,” says postdoctoral fellow Alessandro Cresci at the Institute of Marine Research (IMR).

Simulated wind farm noise

Cresci, together with principal research scientist Howard Browman (also IMR), leads a unique-in-the-world project on whether the noise from wind turbines can interfere with the behavior of small fish larvae. The project is conducted from IMR's research station in Austevoll. In the spring and summer of 2021, Cresci and team took 120 cod larvae and various high-tech equipment with them for an in situ experiment in Bjørnafjorden in Western Norway.

The larvae were placed in specially designed drifting chambers, allowing them to drift freely in their natural environment. The chambers are equipped with a wide array of sensors that detected the behavior of the millimeter-long larvae as the researchers deployed special low-frequency “loudspeakers” to recreate the operational noise generated by wind turbines.

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The researchers are now in the process of analyzing the data they collected during the experiments. At the same time, they are planning new experiments, this time with haddock larvae. The first results from the study are expected to be published during 2022.
The project are a part of a larger research initiative at the institute with the aim of supplying knowledge-based advice to authorities and industry on effects of offshore wind farms on marine ecosystems. There are still many unanswered questions in this area, not least when it comes to effects on the vulnerable early life stages of fish.

For example, turbines are connected by an array of subsea cables that create magnetic and electromagnetic fields. The project will also investigate potential effects of such cables: Do these attract fish larvae? Do they alter their swimming?

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The full article can be found at hi.no