Pods of killer whales are stalking the boats of Alaska fishermen and stealing their halibut catches, leaving the men with no fish and thousands of gallons of fuel wasted trying to flee.

It’s not exactly new that killer whales, also called orcas, can learn to recognize boats and then steal their catches. One article from the Journal of Marine Science traces the habit back to at least the 1960s, and complaints by Japanese fishermen. Now, though, the problem seems to be getting worse. The killer whales are tailing boats all around Alaska, with the majority of the pack seemingly in the strip of water between Russia and Alaska, called the Bering Sea.

One fisherman, Robert Hanson, complained that he lost 12,000 pounds of halibut to whales, and 4,000 gallons of fuel getting away. (Given that one 2014 study said that such thieves could cost boats up to $500 a day, these recent examples seem more serious.) He told of how a pod tracked him for 30 miles and then stayed in the area with him for 18 hours. Dark.

Another one said that sometimes the killer whales will take all of the catch — as much as 30,000 pounds in a day — and leave only the halibut “lips” still attached. Really dark.

As a result of these and other occurrences, the North Pacific Fisheries Management Council is now planning to research the extent of this problem. It’s not clear whether there’s one perfect solution. In the past, others have tried everything from buying decoys to blasting heavy metal, all to no avail — though some think that using steel traps to protect the fish might be better than traditional fishing line. At any rate, something probably needs to change. "It's gotten completely out of control," Hanson said.