The report was produced during most of 2009, and gives a state of art overview of current knowledge on the effects of catch and release practices on these fish species’ welfare, using accessible and peer reviewed published literature as basis for the assessment. Anecdotic and non-published reports have been used to a limited extent as they are regarded as untested or containing unverified statements. The Panel on Animal Health and Welfare discussed the full report in a meeting on the 9th of December, and gave its support to the conclusions drawn by the ad hoc-group.
The report has concentrated on the literature on the aforementioned three species. Transfer of knowledge from other species has only been undertaken to a limited extent as general physiology and responsiveness to stress and handling, may or do, differ significantly among species and may lead to erroneous conclusions.
The report gives a brief overview of the history of catch and release, the three species’ general biology, and current population status in Norwegian rivers. An introductory section describing current knowledge on pain sensation, fear and stress responses has also been added for reader’s information. The main body of the report has been designed to give an outline of current knowledge associated with each of the questions asked by the Norwegian Food Safety Authority, leading up to an answer. The summary responses are as precise as possible. The subjects cover the factors that may affect fish welfare during capture and handling, and the report also includes a section on criteria for humane killing. The effects of various designs of hook and bait types is discussed. The recovery process following release is also discussed, including sections on wound infections, mortality rate, impact on reproductive fitness, predation risk and likelihood of recapture. If catch and release is to be introduced, then the final chapter summarises some possible ways to ameliorate the effects on welfare. The reader will notice that while there is extensive information on some of these subjects for Atlantic salmon, comparatively little is known about the impact of catch and release on anadromous sea trout and Arctic char. Furthermore, in some areas, it has also been difficult to give conclusive answers, partly because there are many interrelated factors that could affect fish welfare that should be taken into account but are beyond the scope of this report, and partly because there is a lack of experimental data. Further progress in these fields can only be accomplished through directed research activities. Based on the review of literature, the panel concludes that catch and release has the potential to harm the fish. During playing and handling of the fish, it will be subjected to stress and other disturbances that may impair the fish’s welfare. These have the potential to cause damages leading to increased mortality (fish with excessive injury and low likelihood to survive should be killed and not released), secondary infections and impacts on reproduction. However, for the anadromous life stages of the species in question (virtually no information for trout and char), available and published scientific literature does not indicate catch and release has any long lasting welfare implications after release. For example, catch and release of Atlantic salmon in rivers at water temperatures less than 17-18 oC have been reported to result in low mortalities (0 - 6 %). The numbers of reliable studies conducted under natural conditions at high water temperatures are few, and to determine reliable mortality levels for catch and release at water temperatures above 17-18 oC more studies should be performed. Given that the catch and release procedures involve subjecting fish to significant stress and other disturbances it is likely that the fish’s welfare is impaired. Welfare issues including survival can be improved by selection of correct fishing tackle, handling procedures, and training of anglers and guides.
Olsen, R. E., Næsje, T. F., Poppe, T., Sneddon, L., & Webb, J. (2010). Risk assessment of catch and release.