EVALUATION OF 4 WETLAND AQUATIC INVERTEBRATE SAMPLERS AND 4 SAMPLE SORTING METHODS

Four sampling devices commonly used to collect aquatic invertebrates i n wetlands were evaluated for their for their ability to capture a sam ple representative of the community. We also evaluated four benthic ma croinvertebrate 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 sa mplers (activity trap and artificial substrate). Sampling gear evaluat ions were based on the number and diversity of aquatic invertebrates c aptured. The Gerking sampler captured significantly (P = <0.0001) grea ter densities of aquatic invertebrates than core or artificial substra te samplers and slightly (P = 0.056) greater densities than activity t raps. Fewer taxa (P < 0.0001) were recorded in core samples than in ot her sampling gears. Sorting techniques included two types of dye, an e lutriator device, and a behavioral extraction device. Dyes were evalua ted on the basis of time taken to sort samples. More time (P < 0.0001) was required to sort organisms from Gerking samples than from cores o r activity traps, regardless of whether samples were stained with Rhod amine B or Congo Red dyes. Efficiency of extracting organisms from sam ples was highly variable for elutriation and behavioral extraction.