Fish fought to exhaustion

Effects of Catch and Release on Physiological Responses and Acute Mortality of Striped Bass
Authors: Julie A. Thompson, Steven G. Hughes, Eric B. May, Wreginal M. Harrell
Journal: American Fisheries Society Symposium 31:489-512
Year: 2002
Where: Maryland, USA
herald death

Fish literally fight for their lives when hooked by anglers. Their struggle to remain in the water will cause a significant number of them to die.

The fight in the striped bass caused:

  • changes in blood acidity
  • changes in blood gases
  • severe stress
The researchers found that the longer the fight with anglers, the more likely was the chance that the fish would later die.


"Targeted species must survive the trauma of catch and release. Fish caught by commercial or recreational methods often struggle to complete exhaustion. This can result in severe physiological disturbances, and a significant percentage may die."
fish fight for their lives


"... Another cause of higher mortality in our study, however, was probably due to fighting the fish to exhaustion, as indicated by the significant changes in pH, blood gas values, and increases in mortality as fish were angled for longer periods. Capture by hook and line induces a biochemical response, and muscular energy is expended, which produces acid metabolites. With severe stress from prolonged exercise, some of these anaerobic metabolites are discharged into the blood and disturb blood chemistry and hemalological parameters associated with respiratory gas transport."

Fish Pain