Selectivity effects on wild white-spotted charr (Salvelinus leucomaenis) during a catch and release fishery

Angling selectivity due to both phenotypic variation and experience of being caught was examined at the individual level in white-spotted charr (Salvelinus leucomaenis) in a multiple catch-and-release experiment in a natural stream. We carried out a field study in a headwater tributary, which is closed to recreational fishing year-round for all species. As the study reach (0.9 km) was located upstream from impassable dams, the white-spotted charr have a non-anadromous life history. After identifying individual fish (n = 415) using numbered anchor tags, eleven fishing episodes at 7-day intervals were conducted using single barbed baited books. Of the 735 marked fish (cumulative count) caught-and-released, 82 deep-hooked fish were released by cutting the line. Only one fish (0.13%) died before release. After these episodes, the experience of being caught of each recaptured fish (n = 366, recapture rate 88.2%, fork length 96-311 mm) ranged from zero to seven times. The number of times caught increased with fork length and age, but was not related to the latest growth or condition factor. In addition, males were caught more often than females. The experience of being caught by angler differed significantly between caught (2.14 +/- 0.25 times) and not caught (1.77 +/- 0.13 times) fish at the 11th fishing episode. A logistic regression analysis was conducted to examine whether eight variables were related to the probability of being caught at the 11th fishing episode. The result suggests that the probability increased with experience of being caught and fork length. Therefore, fish that have been caught and released are more likely to be caught than not caught fish. Our results indicate that catch-and-release regulations can be an effective management tool because anglers may continuously catch fish while conserving fish populations. (C) 2004 Elsevier B.V. All rights reserved.