Off shore wind turbines are now being frequently used as foraging grounds by seals, according to a St.Andrew's University study.

Researchers believe that the reason why these creatures are hunting at the artificial structures might be because of a reef effect. These structures are acting as man-made reefs and therefore altering animals' behavior.

For the study, researchers attached GPS tracking devices to harbor and gray seals on the British and Dutch coasts of the North Sea and observed their movement around wind farms and underwater pipelines.

Researchers found 11 harbor seals near two active wind farms - Alpha Ventus in Germany and Sheringham Shoal in the southeast UK - moved in a grid-like pattern.

"I was shocked when I first saw the stunning grid pattern of a seal track around Sheringham Shoal" - an offshore wind farm in Norfolk," Dr Deborah Russell, a post-doctoral research fellow at the Scottish Oceans Institute, said in a statement. "You could see that the seal 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."

Researchers said that as the percentage of active wind farms continues to expand, the implications on the seals and their prey are unclear.

"Only a small proportion of our study seals utilized wind farms or pipelines," Russell said. "At present these structures cover a small proportion of the extent of the at-sea distribution of seals. As wind farms become more extensive, many more seals will likely be affected," PhysOrg reports.

Researchers now plan to study the effect of massive developmental projects on animal populations.

The finding is published in the journal Current Biology.