Skyscrapers in the sea

Last week’s Grapevine reported on the proposed Hunter Central Coast Offshore Wind Project by Energy Estate and outlined the pros and cons of such a development. The Hunter Offshore Renewable Energy Area extends from Norah Head to Port Stephens is in a horseshoe shape, coming to within 10 kilometres offshore at Norah Head and Port Stephens, which has local residents concerned.

14 June 2023

ALAN HAYES

 

OFFSHORE wind turbines have a growing list of serious problems undermining their future sustainability, but few things look worse for environmental PR than dead whales.

 

Offshore wind farms can negatively affect marine mammals, both during construction and operation stages. The physical presence of turbines, the noise during construction, the underwater noise as well as boat and helicopter traffic can disturb mammals causing them to avoid wind farms.

 

Mammals are very dependent of their hearing systems that are used for several purposes: communication between other individuals of the same species, orientation, finding prey and echolocation. "The behavioural response by marine mammals to noise includes modification of normal behaviour, displacement from the noisy area, masking of other noises, and the impossibility of acoustically interpreting the environment. The consequences from this disturbance could cause problems of viability of individuals, increased vulnerability to disease, increased potential for impacts due to cumulative effects from other impacts such as chemical pollution combined with stress induced by noise (Greenpeace, 2005)".

 

Yet Adjunct Associate Professor Gregory Andrews, who is with the University of Canberra's Institute for Applied Ecology and Director of Lyrebird Dreaming Pty Ltd, said in last week’s Coast Community News (8 June 2023) that “some people on the Central Coast appear to be getting sucked in by misinformation about whales and wind farms - they’re basically conspiracy theories unfortunately".

 

Professor Andrews did not validate his statement, instead offering a range of alternative reasons as serious threats to whales, such as climate change, plastics pollution, discarded nets, ship strikes, over-fishing and toxic pollutions. These are threats that most people are already aware of, including the continual hunting of whales by Japan.

 

Since the offshore wind farm boom began off the Atlantic coast of the United States six years ago, the death rate of humpback whales has roughly tripled and in 2017, three Minke whales washed up on the UK coast. The press reported that the whales were distressed by the offshore wind farm because their sonar communication was confused by the turbines.

 

A 2006 report titled “Effects of offshore wind farm noise on marine mammals and fish”, found humpback whales become uncomfortable with the type of noise produced by wind turbines, even from 60 kilometres away. Yet offshore wind farms (and whatever critical damage they may cause to marine environments around the world) are considered excusable because they are marketed as the only way to avert planetary catastrophe – which is not true. Solar thermal energy has long been recognised as a better solution, because it is able to harness the sun’s energy, does not produce carbon dioxide and will run 24/7 all year round. Australia is well suited for solar thermal energy, because it is bathed in more sunlight than any other country on Earth.

 

What is often forgotten about is that wind turbines are essentially steel skyscrapers, fitted with blades, and affixed to the ocean floor, which is damaged in the process. These ‘wind cities’ are encroaching on the ocean and carpeting the shoreline, creating constant noise pollution in a sensitive environment full of creatures that use sound to survive.

 

The end result is a matrix of spinning blades on the surface of the water, disrupting air patterns and massacring marine bird life. Studies on bird behaviour, have concluded that wind farms represent lost territory, with many birds choosing to abandon the area entirely. As for how large wind turbines are getting, the tallest offshore wind turbine is GE’s Haliade-X standing at 260 metres – or roughly a 70-storey building.

 

Marine mammals, like whales and porpoises. use sound to communicate over long distances, sense the environment and locate prey. This dependence on sound makes marine mammals particularly vulnerable to the effects of man-made noise, including the noisy construction of offshore wind farms. Pile-driving can deafen, injure or even kill marine mammals at close range.

 

A range of measures have been deployed to try and minimise the harm from offshore wind farm construction. Acoustic deterrent devices, which are switched on before pile-driving begins, are supposed to empty the sea of marine mammals, tens to hundreds of metres around the construction site, where the noise is expected to be most damaging. These electronic devices were originally developed for use in the aquaculture industry to deter seals from fish farms.

 

Despite experimental trials, there is limited evidence to show how well acoustic deterrents work during construction. This is, at least in part, due to the difficulties of working in the marine environment, but also because of the challenges involved in studying animals that are highly mobile, and live most of their lives underwater and out of sight. These factors make it very hard to observe how marine mammals react to particular noises or disturbances.

 

A 2021 study into Taiwan’s “Thousand wind turbines project” in the Taiwan Strait said: “The offshore wind farm life-cycle includes planning, construction, installation, operation maintenance, and decommissioning. The noise and vibrations generated by offshore wind turbines during the construction and operation phase have recently been found to negatively impact hearing sensitivity and cause behavioural changes in numerous marine organisms even at ranges many kilometres distance from the wind farm.”

 

In April 2022, a report on a study by Associate Professor Dr Alastair Lyndon at Heriot-Watt University’s Centre for Marine Biology and Diversity found that underwater sea cables for Britain’s offshore wind turbines were emitting electromagnetic fields that were jeopardising the health of  lobsters and brown crabs.

 

“Underwater cables emit an electromagnetic field,” Lyndon said.

 

“When it’s at a strength of 500 microteslas and above, which is about 5 per cent of the strength of a fridge door magnet, the lobsters and crabs seem to be attracted to it and just sit still.

 

“That’s not a problem in itself. But if they’re not moving, they’re not foraging for food or seeking a mate.”

 

Lyndon also “found that exposure to higher levels of electromagnetic field strength changed the number of blood cells in the crabs’ bodies. This could have a range of consequences, like making them more susceptible to bacterial infection.”

 

Yet “the electromagnetic field had a much bigger impact on the lobsters,” said Lyndon.

 

“We put them through a vertical swimming test to check they could get to the surface to find food. The exposed lobsters were almost three times more likely to fail the test, by not reaching the top of the chamber than the unexposed ones.

 

“The exposed lobster were also three times more likely to be deformed. The most common deformities we found included bent and reduced tail sections, which could account for the swimming test results. In addition, some had disrupted eye development or had puffy and swollen bodies.”

 

Wind farms can also have an adverse impact on humans as well.

 

A 2021 study titled “Effects of low-frequency noise from wind turbines on heart rate variability in healthy individuals” said: Low frequency exposure “has been found to cause a variety of health conditions” and that “exposure to low frequency  noise from wind turbines results in headaches, difficulty concentrating, irritability, fatigue, dizziness, tinnitus, aural pain, sleep disturbances, and annoyance” while it also “may cause increased risk of epilepsy, cardiovascular effects, and coronary artery disease”.

 

Recently, Victorian residents sued an onshore wind farm because the noise generated by the turbines meant they were unable to sleep.

 

On 25 March 2022 the Victorian Supreme Court issued its judgment in the ongoing Bald Hills Wind Farm nuisance proceedings in Uren v Bald Hills Wind Farm Pty Ltd [2022] VSC 145. Justice Richards held that operational noise from the Bald Hills Wind Farm was causing a nuisance to two local residents at night time and ordered the operator of the Bald Hills Wind Farm to:

 

• Stop causing nuisance from wind turbine noise at night and implement noise abatement measures to abate the nuisance; and

 

• Pay a total of AU$260,000 in damages to the two local residents.

 

We must decarbonise our energy supply, but we must also ensure there are as few unintended consequences as possible.