Evaluation of Four Wetland Aquatic Invertebrate Samplers and Four Sample Sorting Methods

ABSTRACT Four sampling devices commonly used to collect aquatic invertebrates in wetlands were evaluated for their for their ability to capture a sample representative of the community. We also evaluated four benthic macroinvertebrate sorting techniques for their efficiency in separating organisms from samples. Of the four sampling gears evaluated, two were considered active (Gerking and core samplers) and two were passive samplers (activity trap and artificial substrate). Sampling gear evaluations were based on the number and diversity of aquatic invertebrates captured. The Gerking sampler captured significantly (P = <0.0001) greater densities of aquatic invertebrates than core or artificial substrate samplers and slightly (P = 0.056) greater densities than activity traps. Fewer taxa (P < 0.0001) were recorded in core samples than in other sampling gears. Sorting techniques included two types of dye, an elutriator device, and a behavioral extraction device. Dyes were evaluated on the basis of time taken ...