Hybrid seine for full fish community collections

Abstract

Seines are simple and effective fish collection gears, but the net mesh size influences how well the catch represents the fish communities. We designed and tested a hybrid seine with a dual-mesh bag (1/4 00 and 1/8 00 ) and compared the fish assemblage collected by each mesh. The fine-mesh net retained three times as many fish and collected more species (as many as eight), including representatives of several rare species, than did the coarser mesh. The dual-mesh bag permitted us to compare both sizes and species retained by each layer and to develop species-specific abundance correction factors, which allowed comparison of catches with the coarse-mesh seine used for earlier collections. The results indicate that a hybrid seine with coarse-mesh wings and a fine-mesh bag would enhance future studies of fish communities, especially when small-bodied fishes or early life stages are the research focus.

An evaluation of multiple-pass seining to monitor blackstripe topminnow Fundulus notatus (Rafinesque, 1820) in the Sydenham River (Ontario, Canada)

“…In Ontario streams, fish community monitoring is typically done with single‐pass surveys (Reid et al., ; Stanfield et al., ), which permit greater spatial coverage and a more robust sample size for data analysis than more labour intensive multiple‐pass methods (Stanfield and Kilgour, ). While the first seine haul usually captures a substantial fraction of fishes present (McKenna et al., ), uncommon or rare species may be missed. Blackstripe topminnow was detected in the first seine haul at slightly less than two‐thirds of Sydenham River sampling units.…”

Composition and distribution of fish environmental DNA in an Adirondack watershed

“…Surveys used both model-guided and random procedures to improve the completeness and objectivity of species assessments, following methods of McKenna et al (2012) and McKenna et al (2015) . Shallow habitats with slow-flowing waters and relatively smooth bottoms were sampled with two 15 m sweeps of a seine (9.1 m in length with 6.35 mm mesh wings and 3.175 mm mesh bag ( McKenna et al, 2013 )). Headwaters and sites with higher flow or more rugged bottoms were sampled using a single-pass, backpack-electrofishing technique within a 50 m reach, adjusted for sampling efficiency using the methods of McKenna et al (2015) .…”