Jan Haelters, a marine biologist at the Royal Belgian Institute of Natural Sciences, has long believed that gray seals are capable of attacking, killing, and eating harbor porpoises. But nobody had ever actually seen a seal attack a porpoise. Until now. Haelters and colleagues published an article in 2012 with indirect evidence of seal predation; porpoise carcasses found on the beach with injuries that appeared to be causes by gray seal bites and claw marks. This evidence persuaded many in the scientific community at the time. “Scientists involved in seal research in the Netherlands almost