Comparison of catch per unit effort among four minnow trap models in the three-spined stickleback (Gasterosteus aculeatus) fishery

Abstract

Minnow traps are commonly used in the stickleback (Gasterostidae) fishery, but the potential differences in catch per unit effort (CPUE) among different minnow trap models are little studied. We compared the CPUE of four different minnow trap models in field experiments conducted with threespined sticklebacks (Gasterosteus aculeatus). Marked (up to 26 fold) differences in median CPUE among different trap models were observed. Metallic uncoated traps yielded the largest CPUE (2.8 fish/h), followed by metallic black nylon-coated traps (1.3 fish/h). Collapsible canvas traps yielded substantially lower CPUEs (black: 0.7 fish/h; red: 0.1 fish/h) than the metallic traps. Laboratory trials further revealed significant differences in escape probabilities among the different trap models. While the differences in escape probability can explain at least part of the differences in CPUE among the trap models (e.g. high escape rate and low CPUE in red canvas traps), discrepancies between model-specific CPUEs and escape rates suggests that variation in entrance rate also contributes to the differences in CPUE. In general, and in accordance with earlier data on nine-spined stickleback (Pungitius pungitius) trapping, the results suggest that uncoated metallic (Gee-type) traps are superior to the other commonly used minnow trap models in stickleback fisheries.Catch Per Unit Effort (CPUE) is a concept of great conceptual and practical importance in fisheries sciences [1][2][3] . It is influenced by many factors, both biotic and abiotic, including the fishing gear used 3 . Not surprisingly, effects of different factors and gear types on CPUE in different fisheries have been extensively studied (e.g. ref. 4 and references therein). However, most of these studies have focused on commercially important species, whereas less attention has been placed on species of mainly academic interest (but see refs. 5-8).Except for the mainly historical fishery of the three-spined stickleback (Gasterosteus aculeatus) 9,10 , members of the stickleback family Gasterostidae have not been subject to commercial fisheries. However, they are important model species in behavioural, ecological and evolutionary research [11][12][13][14] . Consequently, a large community of scientists catches sticklebacks from a variety of habitats across their global distribution for diverse research purposes. The methods used in this fishery vary widely, from dip-nets to beach seines and minnow traps. Yet, little research has been conducted in comparing the efficiency of different fishing methods in catching sticklebacks (but see refs. 15-18).Earlier studies on stickleback CPUE have focused on comparisons of different trap models and baiting on nine-spined stickleback (Pungitius pungitius) catches 15,17,18 . In the only study focused on three-spined sticklebacks, Merilä 16 investigated the effect of baiting and trap model on CPUE in the brackish-water environment of the Baltic Sea. While trap model -but not baiting -was found to have a significant influence on CPUE, only tw...

Intertidal Soundscapes of Hardened and Living Shorelines: A Case Study of Habitat Enhancement

“…Minnow trap catches were pooled by sampling location (Budria et al, 2016). To examine community structure among samples with non-zero catch, community abundance per soak time hour was also visualized with nonmetric multidimensional scaling ordination in two dimensions (Okasanen et al, 2022).…”

“…The catches from the minnow traps and fyke nets were used to calculate total abundance, Shannon diversity, Simpson diversity and species richness, all per soak time hour for each deployment. Minnow trap catches were pooled by sampling location (Budria et al, 2016). To examine community structure among samples with non‐zero catch, community abundance per soak time hour was also visualized with nonmetric multidimensional scaling ordination in two dimensions (Okasanen et al, 2022).…”

Comparison of Catch per Unit Effort in three traps for fishing the Common Rudd (Scardinius erythrophthalmus) in Anzali Lagoon, Iran

“…At the same time, the differences in escape probability can explain at least part of the differences in CPUE among the trap models (e.g., high escape rate and low CPUE in red canvas traps). The discrepancies between modelspecific CPUEs and escape rates suggest that variation in entrance rate also contributes to the differences in CPUE (Budria et al, 2015). The Cylindrical pot has two big entrances at the sides that make a high escape rate in this type of trap, but the trap's overall structure was unsuitable, so it failed.…”

Passive traps and sampling bias: Social effects and personality affect trap entry by sticklebacks

“…Research into the susceptibility of different collection methods to these kinds of sampling bias is therefore valuable, both because it has the potential to enable investigators to better interpret the findings of existing work and because, moving forward, it will inform the design of less discriminatory sampling methods. In this study, we investigated whether commonly used (Budria et al., 2015) passive funnel‐type minnow trap, widely used by researchers to capture small fishes, were biased towards capturing individuals with particular behavioural characteristics. These traps consist of a wire mesh cylinder with an inwards pointing funnel at either end (Figure S1).…”