Examining the effects of authentic C&R on the reproductive potential of Northern pike

• Published in: Fisheries Research
• Main Authors: Flink, Henrik, Nordahl, Oscar, Hall, Marcus, Rarysson, Anton, Bergstrom, Kristofer, Larsson, Per, Petersson, Erik, Merila, Juha, Tibblin, Petter
• Other Authors: Organismal and Evolutionary Biology Research Programme, Ecological Genetics Research Unit
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Scientific Publ. Co 2021
• Subjects: Angling; Migration; Recreational fishing; Reproduction; Stress; WILD ATLANTIC SALMON; RELEASE ANGLING ALTER; ESOX-LUCIUS; POSTRELEASE MORTALITY; CATCH; BEHAVIOR; QUALITY; FISH; CONSEQUENCES; SURVIVAL; 1172 Environmental sciences; Atlantic salmon
• Online Access: http://hdl.handle.net/10138/334186

The practice within recreational fisheries to release captured fish back to the wild, known as catch-and-release (C&R), is an increasingly important strategy to protect fish stocks from overexploitation. However, C&R is a stressor and since animal reproduction is particularly sensitive to stress there is reason to suspect that such a practice induces sublethal fitness consequences. Here, we investigated whether and how C&R fishing influenced the reproductive potential in an anadromous population of Northern pike (Esox lucius). First, female pike were exposed to authentic C&R using rod-and-reel fishing in a coastal foraging habitat prior to the spawning period. Next, we observed the migration to the freshwater spawning habitat and compared both the timing of arrival and maturity stage between C&R-treated and control individuals. Finally, to evaluate effects on the quality and viability of eggs we stripped captured control and recaptured C&R-treated females, measured egg dry mass to assess nutrient content, conducted artificial fertilisations and incubated eggs in a controlled laboratory experiment. We found no evidence of C&R causing alterations in either arrival time, maturity stage, or the quality and viability of fertilised eggs. In combination, our results suggest that long-term effects of C&R-induced stress on key reproductive traits of pike, if any, are minor. Peer reviewed