Most serious fishermen keep a hand held spring scale in their tackle box. No they are not very big and many of them scale over a hundred pounds.
Additionally, measuring a 112 lb. fish requires sturdily supporting the scale at a height higher than the fish is long, and then waiting until the fish stops flopping around. This is not easy for a 112 lb. fish. The story would be far more complete and feasible if it described how the fish was weighed.