The seal was surrounded by eight killer whales hunting for food north of Lerwick on March 6 this year. Local drone pilot Nick McCaffrey recorded 38 minutes of the dramatic chase, which saw the seal hide between two rows of mussel ropes at Grunna Voe Farm. He can be seen slipping between the ropes as the killer whales draw closer, in what has been described as previously undocumented behaviour. But the predators pounced when the seal emerged from safety, quickly dispatching their prey. The video was analyzed by Emily Hague, a PhD student at Heriot-Watt University in Scotland, who researches the impact of human activities on marine animals – including man-made structures such as fish farms and offshore energy developments. Ms Hague said: “Interactions involving man-made structures are rarely, if ever, caught on camera. “That makes this material very special and very insightful from a scientific point of view.” The film provides a “new perspective” on how marine life and man-made structures can coexist in the sea, Ms Hague added. “It is exciting that these new structures in the marine environment are potentially used by prey to hide from predators.” Image: The dramatic chase was captured by a drone The video also sheds light on the potential dangers facing marine animals. “Last year a juvenile member of this killer gang died entangled in the rope and was found in Orkney,” Ms Hague said. “If this group spends a lot of time around marine structures, then that can have associated risks, such as entanglement.” Image: The video is a rare example of marine life interacting with man-made structures Mr McCaffrey captured the video after he and other wildlife enthusiasts were alerted to the orcas’ arrival by the Shetland Orca Sightings Facebook page, which is managed by wildlife photographer Hugh Harrop. He followed the path of the pod as the orcas traveled from just south of Lerwick towards Grunna Voe. Ms Hague’s full findings were published on Thursday in the scientific journal Aquatic Mammals.
