RE:What do you do?!
I hate those situations, making the moral decision is easy, it's the unknown response of a strangetr that is the problem..
I would like to think that an offer to show the "sport" how to handle a fish and why would be well received but I also know that in this day and age, it could get you hurt.
I have a similar story to address the EPO issue. Every Thanksgiving my hunting buddies and I spend the morning on a pheasant hunt in the public fields. We all are members in an out of state hunting lease due to our belief that hunting public land in Mass. is extremely dangerous because of sports similar to hose that Hawkeye ran into. But, being home with the families for the holidays and the need to get out makes the morning a usually pleasant experience.
Two years ago, we were in Miles Standish, moving to another spot, the dogs were in the crates, the guns were unloaded and in cases (pre trigger locks) and as we were driving down the road we were following another truck by about 50 yards.
A nice bird flies across the road and lands in a tree on the opposite side of the road and the guy in front of us throws on the brakes, hops out with his shotgun & plugs the bird in the tree from beside his truck. We pull up as he is picking up whats left of the bird and ask him if he knows it's illegal to shoot from the road (we didn't bother to address the loaded gun in the vehicle issue). He gives us the finger, hops in his truck & drives off.
We gave his license plate number to the EPO. They called my buddy that afternoon and asked for a statement and then went to his home. Guess what they found there?
From what I remember, the guy lost his license + was issued a hefty fine.
My long winded point is that we have to be the eyes & ears of the EPO and be willing to appear as a witness if we report someone. An anonymous report just doesn't work, it leaves too many opportunites for the "sports" to get away.