Noise caused by building wind farms ‘could be killing fish’

THE noise caused by building wind farms could be killing fish by making them more vulnerable to predators, a study suggests.

Recordings of pile-driving, used in the construction of marine infrastructure such as wind farms and piers, disrupted the abilities of individual sea bass to coordinate their movements with one another, researchers from the University of Bristol found.

Without the ability to “school”, fish are unable to exchange information and confuse predators, making it more likely they will be eaten, say researchers. The study involved using computer tracking software to analyse the movement of 450 sea bass and shoals in the university’s aquarium. They found the fish became “less cohesive and coordinated” during the playbacks, compared with when they were played normal ambient sea sounds.

Dr Christos Ioannou, from the university’s School of Biological Sciences, said: “By using state-of-the-art computer tracking software, we were able to measure and analyse the movement of individual fish and the shoal as a whole in great detail.

“This is one of the few studies to explore how pollution from human activity impacts schooling behaviour in fish.

“Previous work has mostly focused on the effect of noise on the physiology and behaviour of individual animals.”

The findings were published in the Proceedings of the Royal Society B journal. The next step will be to move away from the lab and test the effect of the recordings under natural conditions.

Wind farms have already been blamed for killing bats and seabirds while some studies have suggested the noise can prevent people from sleeping and even cause mental health problems. Noise emanating from passing ships is also thought to disturb animals such as killer whales and dolphins by preventing their ability to communicate and hunt for fish.

Research has found that the average intensity of noise next to ships is 173 underwater decibels, equivalent to 111 decibels through the air – about the sound of a loud rock concert. Last year, research from the University of Exeter found wind farms are probably killing tens of thousands of bats a year, even where risk assessments have been carried out to prevent the deaths.

Researchers used sniffer dogs to locate the bodies of stricken bats near turbines to find out the scale of the problem. A survey of 29 wind farms showed that 194 bats a month were killed, although the figure is likely to be higher because many of the dead creatures would have fallen prey to scavengers.

Extrapolated to all of Britain’s onshore wind farms it could mean around 80,000 bats are being killed each year. The research also showed that the risk of bat death increased by 18 per cent for each extra metre of blade length. Some individual turbines were found to kill around five bats a month.