Sport fishing causes significant welfare harm to fish; the evidence for fish pain makes catch-and-release practices ethically complex.
Fish hooked through the mouth or body experience acute pain from the mechanical trauma. The stress of fighting against a line causes physiological responses including cortisol spikes, lactic acid buildup, and exhaustion. Deep-hooked fish who swallow the hook suffer internal injuries that cause slow death even after release. The scale of recreational fishing means these welfare harms occur billions of times annually.