I picked this up on a local beach recently; I’m now trying to find out how to report it: a Maine Fisheries halibut tag. As the tag hasn’t been cut, I’m wondering if the fish in question was eaten by something considerably larger, and now only its tag survives!
The more common transatlantic tags come off Newfoundland lobsters; they’re usually cut, i.e. someone has caught the lobster but they haven’t returned the tag to the fisheries service as they should have.
