Study: Offshore wind farms could disturb sea mammals

By Gwyn Wright via SWNS

Offshore wind farms could disturb sea mammals such as seals and dolphins, suggests a new study.

Researchers have found the creatures could change their behavior because of noise emitted by the eco-friendly energy generators.

The sounds they emit could mask calls from whales which eat them but the full impact of the structures on their behavior remains unclear.

Their impact could depend on the number of turbines in one place and the areas they affect.

Harbor porpoises are often seen swimming near European wind farms, which means their impact may not be as clear-cut as it seems.

It remains unlikely that levels of din could injure animals or damage their hearing, the scientist added.

Lead researcher Frank Thomsen from company DHI said: “It is very unlikely that operational noise will lead to any injury or even hearing impairment, but behavioral changes could be a concern, as our study shows.

"It is possible that impact zones of individual turbines overlap, but that still does not mean that the wind farm is a no-go area for marine life.

“We see harbor porpoises frequently swimming in the vicinity of turbines.

“Since offshore wind farms have a relatively long lifespan, and there will be many of them, the potential impacts should not be overlooked.

"The point of our work is to raise awareness."

When wind farms pop up they are noisy but they tend to be well built and regulated.

Once they become operational they emit a constant level of sound as they produce renewable energy to power our homes.

For the study, a research team reviewed published sound levels from operational wind farms.

In general, bigger turbines were found to be noisier.

Newer wind farms using quieter driving technology can to a certain extent cancel out the impact of larger turbines.

Older gear box technology reaches disruptive levels for marine mammals up to 6.3 kilometers (3.9 miles) away.

In contrast, newer direct drive turbines are expected to only impact animal behavior within a 1.4-kilometer (0.9 mile) radius.

The findings were presented at the 182nd Meeting of the Acoustical Society of America in Denver, Colorado.