Sea birds might pay the price for green electricity
WIND farms could damage the populations of some bird species if they are not carefully sited. That is the conclusion of a review of all the impact studies done do far.
The review focused on the overall number of birds in and around wind farms, rather than just the number killed by collisions with turbines, and included all rigorous studies done worldwide, from Scandinavia to Wyoming. "Available evidence suggests that wind farms reduce the abundance of many bird species at the wind farm site," it concludes. Among the worst affected are waders and ducks around wind farms on estuaries and in shallow coastal waters.
"We are not saying we should stop building wind farms. Birds would suffer much more from climate change if we don't," says Andy Pullin of the Centre for Evidence-Based Conservation at the University of Birmingham in the UK, one of the authors of the review. "But the data shows we have to be much more careful about where we site them." Wind farms built in deeper water further from the shore might prove better for birds, he says.
The findings could be especially significant for the UK, which has the biggest offshore wind energy programme in the world. One of the most controversial projects would cover Shell Flat off Blackpool in north-west England with turbinesm potentially threatening the wintering grounds for the common scoter(Melanitta nigra), a sea duck on the British "red list" of endangered species.
"If Britain builds as many wind farms as the government is talking about, it could use up all the offshore habitat for cudks and waders," warns the lead author, Gavin Stewart, also at the Centre for Evidence-Based Conservation.
The finding (Systematic Review 4, at www.cebc.bham.ac.uk) will be unwelcome news for the UK government, one of the sponsors of the review, whichis heavily committed to wind power to meet the country's targets for cutting greenhouse gas emissions, and for the Royal Sosiety for the Protection of Birds (RSPB), which supports wind power.
"Compared with past assaults, such as organochlorine pesticides, loss of hedgerowsm, illegal persecution of birds of prey and intensive agriculture, wind farms should be low down the scale of threats," says Mark Avery, director of conservatioin at the RSPB. "However, if we put them in all the wrong places then that picture would be very different." Yet when it comes to offshore wind farms, we do not even know what the wrong places are, Avery says, because so few impact studies have been done.
One worrying aspect of the review, says Stewart, is that aboundance may continue to decline with time. "Most studies look at one year, but the few longer-term studies suggest that a wind farm will have a much bigger impact over its entire lifetime."
Another worry is that most of the studies so fay have looked at small wind farms. The fear, unanswered in this study, is that a small number of bigger farms may have a greater impact on bird populations than a series of smaller one.
Another question, say the researchers, is whether a few big turbines do less damage that a greater number of smaller ones. "Better understanding is needed of the cumulative impact of more and more wind farms," says Avery. "We will object to any wind farms that seriously threaten important populations of birds."
The reserchers are scathing about the poor quality of research into the impact of wind farms around the world. The findings of many studies are kept secret for commercial reasons, while supposedly public information produced for plannning applications comes without raw information or is of poor quality, Stewart complains. "It's difficult even to find out what data is out there, and when we know it's there, it is extraordinarily difficult to get hold of."