Fish hooked in the lower jaw, bottom of the mouth and eye area have moderate mortalities while the highest mortalities are those hooked in the gill and stomach areas. Fish that are captured and released may die for many reasons, but stress and wounds are two pr nnary causes. Stress includes anything that adversely affecu a fish. Catching, handling and release causes stress to a fish. The rougher a fish is handled from time of hooking to release, the higher the degree of stress.
Stress can cause shock which occurs when the blood circulating system shuts down.
Shock and death occurs when substantial bleeding lowers the blood pressure. Exertion on the part of the fish while being played causes lactic acid to accumulate in the fish s muscles. This leads to blood acidification and a temporary disruption of many metabolic processes. Very high levels of lactic acid can cause the brain to start mixing up signals from other organs and may cause shock and death. Survival is dependent upon blood acid levels returning to normal.