A good point. From my own experience if a fish shows any signs of bleeding so much that you can see it easily in the water then that fish will almost certainly die. When you think about it a teaspoon of blood for a salmon is a huge amount. Obviously these incidents cannot be helped from an angling perspective.Depends where bleeding from, if gills no chance. If just blood from hook in mouth or roof then every chance. Remember blood in water plumes up making it look worse than actually is. That said fresh fish are more vulnerable than resident river fish. I think the stresses of osmosisacle physiological transgression increases physical vulnerability. Backend coloured fish appear more robust after becoming accustomed physically to fresh water... Just my view mind..