Offshore wind farms have been increasing in number as society's energy demands are also on the rise. By essence, a wind farm is a group of wind turbines placed on a singular location and used to produce energy. The location can either be on land (onshore) or offshore.
Offshore wind farms have several advantages over their onshore counterparts. First of all, they are less obtrusive because of their distance which mitigates their size and noise. The average wind speed and capacity factors are also higher.
Using a GPS tracking system, it was discovered that offshore wind farms are also attracting hungry seals. At least 11 harbor seals were found to have visited two existing offshore wind farms on the UK and German coasts. These have been identified as the Sheringham Shoal and the Alpha Ventus respectively.
"I was shocked when I first saw the stunning grid pattern of a seal track around Sheringham Shoal," says Deborah Russell from the University of St Andrews. "You could see that the individual appeared to travel in straight lines between turbines, as if he was checking them out for potential prey and then stopping to forage at certain ones."
Scientists have been tracking around 200 animals using a GPS monitoring device. This would include the gray and harbor seals which had been tracked near Germany's and Britain's offshore wind farms. While it is true that only a handful of these seals had been tracked down, it was noticed that they would regularly go back to the place and forage for food around the turbines.
Based on their route patterns, it shows that the seals understand very well what they were searching for. Scientists also discovered that a few seals would track undersea pipelines and could even take up to 10 days of food hunting.
The study is the first of its kind to record changes on how a seal behaves around wind farms. The latter now joins other places such as shipwrecks, oil rigs, and purpose-built cement "reef balls" in their role as "artificial reefs" which provide new habitat options.
So far, scientists have recorded only around a dozen seals exploring the farms which is quite a small number since there are around 55,000 harbor seals and 65,000 gray seals that populate the British coast. It remains unclear if future changes to the farms would result to a long-term benefit or would cause danger to the seals. Planners should therefore find ways to customize a wind farm construction in order to maximize its benefits to the seals and other marine animals while also practicing effective cost planning.
