Sustainable sport fisherman

I was at the boat ramp today watching the terrorist boaters from Sydney launching and retrieving there boats while on holidays. I watched as one bloke showed off his catch to a bystander and then he hurled the dead sting ray back into the water. It was a funny colored fish so I suspect it might have been pretty rare,it is now rarer than before. They also caught some large fish and took a fillet from the fish leaving about a kilo of good meat on the bones they threw back,if this is you wake up to yourself  this is not sustainable and it is a waste.