Fish thrive around Danish offshore wind farm

The report focuses on Danish wind farm Horns Rev 1, one of the world’s largest offshore wind power farms. The 80 huge turbines at Horns Rev 1 are located just off Denmark’s westernmost point and is located in relatively shallow water, no more than 20m deep, and is an area which is teeming with fish.

Before the park was built, researchers from DTU Aqua, National Institute of Aquatic Resources in Denmark sailed out to conduct a survey of fish life in the area. Biologists then compared the data gathered at that time with the situation in the area seven years after the wind turbine blades began to turn.

"Our study showed that the turbines have not adversely affected fish life in the area,” says biologist Claus Stenberg from DTU Aqua.

Offshore turbines at Horns Rev are sunk deep into the seabed and surrounded by a rim of large piles of stones. The study suggests that these stone structures also act as artificial reefs, providing enhanced conditions for fish, with an abundant supply of food and shelter from the current, and attracts fish which like a rocky sea bottom. As such, the turbines have created habitats for a number of new species in the area, such as the goldsinny-wrasse, eelpout and lumpfish.

The study also shows that wind farms have not been a threat nor of particular benefit to the sand eel.

The study is the first to examine the effects of a Danish wind farm on fish life. However, researchers do not expect that the results will necessarily be replicated in the other 11 wind farms located in Danish waters.

"Horns Rev is situated in an extremely tough environment with strong wave action, which means for example that seaweed forests, together with the small fish that live in them, cannot establish themselves. We would therefore expect the positive reef effects to be even greater still in a park located for example in the more sheltered Kattegat," says Mr Stenberg.

Since the Horns Rev 1 was built, the area has been closed to all fishing activities. As a result, the park has become a kind of mini protected area, although it has been too small to have had any significantly positive effects on local fish stocks.