Baiting improves CPUE in nine-spined stickleback (Pungitius pungitius) minnow trap fishery.

Juha Merilä

doi:10.1002/ece3.1635

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.

Highlights

Apart from the three-spined stickleback (Gasterosteus aculeatus) fishery for the purposes of fish oil production and/or poultry forage (e.g., J€arvi 1932; Ojaveer 1999), the interest toward sticklebacks as a fishery target has received little attention in the scientific literature
Repeated measures analyses revealed that total catch per unit effort (CPUE) was significantly influenced by treatment (Table 1a), with baited traps yielding a higher CPUE than the unbaited or foil traps (Fig. 1)
The baiting mainly seemed to influence the CPUE of older and larger nine-spined sticklebacks, but it did not have an effect on the CPUE of the young-of-the-year fish

Summary

Introduction

Apart from the three-spined stickleback (Gasterosteus aculeatus) fishery for the purposes of fish oil production and/or poultry forage (e.g., J€arvi 1932; Ojaveer 1999), the interest toward sticklebacks as a fishery target has received little attention in the scientific literature. This is in spite of the fact that a large worldwide community of researchers has utilized sticklebacks as models in their scientifically diverse research since the 1960s (for reviews, see: Bell and Foster 1994; O€ stlund-Nilsson et al 2007; von Hippel 2010; Wootton 1976, 1984, 2009; Meril€a 2013). The effect of baiting on CPUE may differ even among ecologically similar species (Løkkeborg et al 1989; Furevik and Løkkeborg 1994) and within a given target population depending on the prevailing conditions (e.g., Bigelow et al 1999; Stoner 2004; Dupuch et al 2011)

Objectives

Methods

Results

Conclusion