Determinants of Hooking Mortality in Freshwater Recreational Fisheries: A Quantitative Meta-Analysis
Daniel Hühn and Robert Arlinghaus
Abstract .—In recreational fisheries, catch and release is widespread and practiced under the assumption that released fish survive the capture event unharmed. To improve understanding about the lethal impacts of catch-and-release recreational angling, a quantitative meta-analysis of the literature on hooking mortality and its determinants was conducted focusing on freshwater fishes. Studies were initially selected based on the occurrence of the study species in European recreational fisheries. Because original studies from European freshwater or diadromous fish species were rare, studies from the same genus as native European species were also included in the meta-analysis. Mean hooking mortality ± SE across all species was 15.9 ± 1.3% (n = 252 hooking mortality estimates in n = 107 studies), with a median of 7.8% and a range from 0% to 88.5%. The distribution of hooking mortality estimates was highly skewed towards low values; about 60% of all hooking mortality values were below 10%. Average hooking mortality varied between fish families and was highest for Percidae (mean ± SE, 19.9 ± 5.3%) followed by Salmonidae (15.9 ± 1.4%), Esocidae (14.9 ± 7.0%), and Cyprinidae (5.7 ± 1.6%). Hooking mortality was positively related to water temperature and was significantly higher for natural baits and barbed hooks than for artificial baits and barbless hooks. Size of fish and type of hook were unrelated to the level of hooking mortality. To minimize hooking mortality on European fish species, we recommend the use of barbless hooks and artificial baits and we suggest avoiding catch and release of fish during high water temperatures. Further research on the impacts of catch and release on a number of European fishes is recommended because of the limited coverage of species-specific information in the contemporary literature.