title: Baiting improves CPUE in nine-spined stickleback (Pungitius pungitius) minnow trap fishery.
abstract: Whether or not baiting influences stickleback catch per unit effort (CPUE) remains a matter of debate among stickleback researchers: While the opinions about the impact of baiting on CPUE differ, supporting quantitative data are scarce. The effect of baiting and trap type on nine-spined stickleback (Pungitius pungitius) CPUE was studied in a field experiment conducted over four consecutive days in a small pond in northeastern Finland. The results show that baited traps yielded better (mean CPUE = 1.24 fish/trap/d) catches than unbaited traps (mean CPUE = 0.66); however, there were also differences in CPUE depending on the type of collapsible trap that was used. The trap type effect on CPUE seemed to differ among age classes - the finer meshed trap caught more young-of-the-year fish than the coarse-meshed one, whereas the opposite was true for the older and larger individuals. The results agree with those of an earlier more restricted study conducted in the same locality: Together, these results provide strong evidence for the positive impact of baiting on nine-spined stickleback CPUE.
authors.affiliation: Department of Biosciences, Ecological Genetics Research Unit, University of Helsinki P.O. Box 65, Helsinki, FI-00014, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Merilä
keywords: Bait; CPUE; Haemopis sanguisuga; Pungitius pungitius; minnow trap; ninespine stickleback