Evaluating adequacy of the representative stream reach used in invertebrate monitoring programs
Selection of a representative stream reach is implicitly or explicitly recommended in many biomonitoring protocols using benthic invertebrates. We evaluated the adequacy of sampling a single stream reach selected on the basis of its appearance. We 1st demonstrated the precision of our within-reach sampling. Then we sampled 3 or 4 reaches (each ∼20× mean width) within an 8-16 km segment on each of 8 streams in 3 ecoregions and calculated 4 common metrics: 1) total taxa; 2) Ephemeroptera, Plecoptera, and Trichoptera taxa; 3) biotic index; and 4) Shannon's diversity index. In only 6% of possible cases was the coefficient of variation for any of the metrics reduced >10% by sampling additional reaches. Sampling a 2nd reach on a stream improved the ability to detect impairment by an average of only 9.3%. Sampling a 3rd reach on a stream additionally improved ability to detect impairment by only 4.5%. We concluded that a single well-chosen reach, if adequately sampled, can be representative of an entire stream segment, and sampling additional reaches within a segment may not be cost effective.
Citation Information
Publication Year | 1999 |
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Title | Evaluating adequacy of the representative stream reach used in invertebrate monitoring programs |
DOI | 10.2307/1468466 |
Authors | C.F. Rabeni, N. Wang, R.J. Sarver |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of the North American Benthological Society |
Index ID | 70021525 |
Record Source | USGS Publications Warehouse |