October 29, 2015 — Scallops, like deer, freeze in the headlights. A blast of artificial light causes scallops to refuse to swim. It’s an unusual reaction, given that marine creatures generally either flock to the light, like moths, or scurry from the intrusion. Understanding this odd behavior might help governments take better care of scallop fisheries.

Liese Siemann, a research biologist at the Coonamessett Farm Foundation in Massachusetts, discovered the mollusks’ motionlessness by accident while watching videos of Atlantic sea scallops off the east coast of Long Island, New York. Traditionally, scientists survey scallop fishing grounds by dredging—scooping creatures from the seafloor to count them. But Siemann and her team were testing video survey equipment, trawling a camera through the sea. She says video surveys are safer for protected species or in protected areas, and are becoming more common.

Looking at the footage, Siemann noticed that when the camera’s light was off, scallops swam away as the sled approached. But when the camera’s light was switched on, the scallops seemed to stay put. Scallops aren’t the most mobile animals, but they can swim a few meters at a time by opening and closing their shells. They can also spin around, jump, and flip over if they get turned upside down.

Read the full story at Hakai Magazine