Benthic macroinvertebrates were used as biological water quality indicators in Wheeling Creek. Macroinvertebrates were chosen because they are more abundant and easier to capture than fish and because they are easier to identify than algae or protozoans.
were collected using a Hess sampler in larger (fifth and sixth-order) streams and a Surber
sampler in smaller streams. Left: Sampling macroinvertebrates. Photo: Dr. Ben Stout
Macroinvertebrates were identified and enumerated, and the number of organisms at each site was estimated from the average of three 0.1 m2 (1.1 ft2) samples. In addition to the total number of organisms, several measures of diversity are described below. Summaries at the taxonomic level of order, for instance the mayflies, stoneflies, beetles, and other organisms, are also described below. Right: Checking rocks for bugs. Photo: Dave Saville
Benthic macroinvertebrate densities were reported as the total number of organisms per square meter of stream bottom. Additionally, the number of mayflies, stoneflies, caddisflies, beetles, midges, crustaceans, worms, and mollusks was reported. The total number of identifiable kinds of organisms was reported as richness. The Shannon index was used as a diversity index. The EPT index, a measure of the "quality" of the invertebrate community, was calculated as the number of mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) divided by the total number of midges.
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