Catch-and-Release Practices in Recreational Fisheries

Catch-and-release (C&R) is widely adopted in recreational angling to reconcile fishery enjoyment with conservation objectives. By returning captured fish to the water, anglers seek to maintain stock abundance, genetic diversity and ecological function. However, capture and handling impose physiological and behavioural stressors—including exhaustive exercise, air exposure, changes in water temperature and injury from hooks—that can lead to sublethal impairments or delayed mortality. Research has focused on quantifying stress responses (e.g. blood‐chemistry disturbances), evaluating reflex impairment as a predictor of survival, and identifying gear and handling modifications to reduce harm. Global studies reveal species‐specific sensitivities and context dependence on factors such as water temperature, fight intensity and hooking location. Best practice guidelines now emphasise rapid unhooking, minimal air exposure, use of barbless or appropriately sized hooks and release techniques that promote rapid recovery. These efforts underpin adaptive management strategies, inform angler education and support the sustainability of recreational fisheries worldwide.

Research from Nature Portfolio

Recent methodological advances have enabled minimally invasive sampling of fish blood within home tanks, combining gradual anaesthesia and gill irrigation to maintain acid–base stability. This approach yields accurate measurements of pH, lactate and stress hormones in small individuals, facilitating finer analyses of capture stress across multiple species without the confounding effects of traditional grab-and-stab or surgical cannulation techniques. Such precision supports the refinement of C&R protocols and enhances the validity of physiological assessments in situ.

Investigations into the interaction of exercise-induced stress and climate warming have demonstrated that elevated water temperatures substantially reduce post-release survival, particularly among high-performance phenotypes. Individuals exhibiting vigorous escape responses take longer to recover metabolic homeostasis and suffer higher mortality at temperatures projected under climate change. This finding suggests that C&R practices may inadvertently select for low-performance traits, with potential consequences for population dynamics and ecosystem function under warming regimes.

Catch-and-Release Practices in Recreational Fisheries publication trend

The graph below shows the total number of articles in catch-and-release practices in recreational fisheries across all publications each year (not limited to Nature Index journals).

Technical terms

Physiological stress response: The array of hormonal and metabolic changes—such as elevated cortisol, lactate and altered pH—that occur in fish following capture and handling.

Reflex impairment: A quantifiable reduction in neuromuscular responses (e.g. righting, tail grab) used as an indicator of vitality and predictor of delayed mortality.

Post-release mortality: The proportion of fish that die after being returned to the water following catch-and-release, often occurring hours to days after release.

Acid–base balance: The maintenance of blood pH and bicarbonate concentration, crucial for cellular function and often disrupted by capture-induced hypercapnia or lactic acidosis.

High-performance phenotypes: Individuals characterised by elevated metabolic or locomotor capacity whose stress recovery dynamics and survival may differ from average conspecifics under environmental stressors.

References

1. A method for measuring meaningful physiological variables in fish blood without surgical cannulation. Scientific Reports (2023).
2. Rising temperatures may drive fishing-induced selection of low-performance phenotypes. Scientific Reports (2017).
3. The influence of water temperature and accelerometer-determined fight intensity on physiological stress and reflex impairment of angled largemouth bass. Conservation Physiology (2014).
4. Estimating and mitigating post-release mortality of European eel by combining citizen science with a catch-and-release angling experiment. Fisheries Research (2018).
5. Post-release effects of catch and release angling for sea trout: Mortality, growth and wound healing. Fisheries Research (2023).