Resource: Best Practices, Recommendations for Releasing Marine Recreationally Captured Chinook or Coho

Hinch, S.G., S.D. Johnston, E.L. Lunzmann-Cooke, K. Zinn, and B.J.L. Hendriks. 2024. Enhancing the sustainability of capture and release marine recreational Pacific salmon fisheries using new tools and novel technologies. Final Report on Project 2019_058 submitted to the British Columbia Salmon Restoration and Innovation Fund, July 12, 2024.

Pacific Salmon Ecology and Conservation Laboratory Department of Forest and Conservation Sciences
University of British Columbia

Fishing recommendations

Lessen your interactions – if you catch a fish that is legal to keep, do so, and do not continue fishing for salmon once you have your legal limit thereby reducing the number of fish that must be released.

Avoid small fish – move fishing locations or increase size of lures to limit interactions with smaller (e.g., sub-legal) fish as these individuals are more susceptible to injuries and mortality associated with catch and release interactions.

Avoid fishing locations if predators are present – marine mammal predators may remove fish from your lines, injure fish during the fight, or capture fish post-release before they have had time to recover from the fight.

Avoid catch-and-release when surfaces waters are at or above 18°C – these temperatures are known to increase mortality post-release (Teffer et al. 2019). Fish may appear healthy when released, however the added thermal stress interacts with all other capture and handling factors leading to a much higher probability of mortality.

Gear Choice Recommendations

Use smaller hook sizes – larger hooks are related to more severe injuries and larger gap widths increase probability of eye injury and decrease survival probability (Johnston et al. 2021). Gap width of 15 mm (e.g., 3/0 ‘Octopus’ hook) or smaller is recommended.

Avoid treble hooks – although treble hooks were less likely to cause eye injuries, their use increased hook wound severity and decreased survival probability (Zinn et al. 2024; Clarke et al. 2021). This was especially pronounced in smaller fish that are non-retainable in the fishery (e.g., Chinook salmon <62 cm).

Avoid tandem hook point setups – (e.g., when using bait or artificial lures) – multi-hook setups are prone to multiple hooking locations on the fish’s body which increases the likelihood of a lethal hooking location.

Avoid flashers – In-line flashers cause higher metabolic rates during landing and prolong the metabolic recovery of the ‘fight’ after release which means fish are less likely able to swim rapidly post-release and would be at higher predation risk; this phenomenon is greater for female salmon relative to males (Van Wert et al. 2024).

Landing Recommendations

Land fish as quickly as possible – prolonged anaerobic exercise (aka burst swimming) increases the metabolic oxygen debt which if it gets too large, can lead to cardiac arrest. This is particularly a problem if flashers are used when water temperatures are warm and fish are exposed to air prior to release. Decreasing fight time reduces the time needed for fish to re-oxygenate their organs (Birnie- Gauvin et al. 2023).

Avoid air exposure – air exposure increases anaerobic metabolic costs and thus increases recovery time and the probability of mortality (Raby et al. 2012). If it’s not possible to avoid air exposure, limit this to less than 10 seconds (Cook et al. 2015).

Avoid using landing nets – the use of landing nets including ‘fish-friendly’ ones made of rubber- coated or nylon are associated with fin splitting and scale loss (Johnston et al. 2023; Lunzmann-Cooke et al. 2022; Zinn et al. 2022; Barthel et al. 2003). If a net must be used so that fish can be measured, ensure fish remain in the water, and the net remains loose to help avoid contact with fins, dermal tissue, and the mucous layer.

Handling Recommendations

Limit touching of fish – reduce physical handling as much as possible, do not use gloves to handle fish.

Handle with wet hands – when required to handle fish, only do so with bare wet hands. Only touch areas like the caudal peduncle and under the pectoral fins where the fish can be evenly supported, and never hold fish vertically by the tail or touch the gills.

Release Recommendations

Release fish at the water line – bringing the fish aboard with a net and handling the fish with hands will cause injuries and can lead to delayed mortality. Use a gaff, or other purpose-built tools, to release fish at the water line.

Release immediately – release the fish immediately rather than trying to ‘revive’ them next to the boat. Revival techniques increase stress and can cause more harm than good (Robinson et al. 2013). Attempts at reviving when surface waters are warm will further stress fish and can cause post-release mortality (Robinson et al. 2015). Only delay the release of fish if they appear moribund or have lost full equilibrium. Use a submerged recovery bag to protect the fish from predators while it recovers which should only take a few minutes.