Reliability of catch per unit effort (CPUE) for evaluation of reintroduction programs – A comparison of the mark-recapture method with standardized trapping

Catch per unit effort (CPUE) is used as a standardized trapping method by local fishermen and in monitoring studies. In this study, CPUE was compared with population estimates made with a capture-recapture method based on the passive integrated transponder (PIT-tag) marking of individuals. The results show a stronger positive correlation between the estimated population sizes from the capture-recapture method with an estimated CPUE effort of 120 traps. The fishermen used 15 traps, and even this effort showed a fair correlation with the mark-recapture estimates. This indicates that the standardized way of trapping with 15 traps can be used to evaluate reintroduction programs and monitor crayfish populations