The Catch and Release angling: implications for the management and conservation of the Mediterranean trout in Central Italy

Overexploitation and consequent depletion of the breeding stock is one of multiple stressors affecting Mediterranean trout Salmo cettii Rafinesque, 1810 in central Italy. The practice of total Catch and Release (C&R), combined with gear restrictions and seasonal closures, reduces catch-related impacts. To test for the effects of C&R management, the goals of the study were to: (i) analyse the status of trout inhabiting 8 C&R areas of the Nera River Basin, and (ii) compare the results with those from 11 exploited areas and 15 no-fishing areas. Fish data were collected by electrofishing from 1997 to 2020. Abundance, growth, age structure, and relative weight were estimated. Trout populations in the C&R sectors exhibited high abundances, well-balanced age structures, and a congruous number of age classes according to the longevity of the species. However, the abundance values never reached those of the no-fishing areas. The results provided evidence for an unbalanced population structure in fishing areas, where intensive size-selective harvest caused negative demographic effects, especially on older fish, and the legal-limit length was not adequate for maximal yield length. C&R angling appeared to maintain the fishery value of trout stocks favouring the conservation of native trout, although a certain impact on fish population status remains and thus, it cannot completely replace the adoption of more restrictive criteria