Not all methods are created equal: assessment of sampling methods for crayfishes and fishes in southern Appalachian streams

Abstract

We compared the effectiveness of three sampling methods (kick seining, electrofishing, and nest trapping) to collect crayfishes and fishes, simultaneously, in southern Appalachian Mountain streams (Alabama, USA). For crayfishes, kick seining collected the highest species richness and most individuals. However, by combining kick seining and electrofishing collections, we decreased the number of sites needed to accurately assess crayfish richness relative to using one method. For 9 of the 13 species collected, no differences in crayfish sizes or sex ratios were detected between electrofishing and kick seining. In the remaining four species, electrofishing collected larger crayfishes and more females than kick seining. For fishes, electrofishing was most effective at assessing fish species richness. Sampled fish richness was higher when electrofishing in streams with higher water temperatures and width-to-depth ratios, as well as lower conductivities and smaller substrates. Electrofishing was the most effective sampling method for collecting Centrarchids, whereas kick seining was most effective at collecting Cyprinids. Nest traps were the least effective sampling method. We conclude that using a combination of kick seining and electrofishing is best for assessing stream fish and crayfish assemblages, simultaneously, which can improve management, biomonitoring, and understanding of the complex relationships between these faunal groups.