Effects of biotic assemblage, classification, and assessment method on bioassessment performance

• DOI: 10.1139/f05-222
• Publication Date: 2006-01-23T15:21:17Z
• Authors: Raphael D Mazor; Trefor B Reynoldson; David M Rosenberg; Vincent H Resh
• Keywords: Periphyton; Ecoregion; Biotic index; Benthos

Biomonitoring requires thorough evaluation of methods used to detect impairment. Using a data set 202 reference sites and 66 test from the Fraser River, British Columbia, Canada, we analyzed effects assemblage (benthic macroinvertebrates periphyton) site classification (ecoregion, stream order, null models, biotic groups) on two bioassessment (BEAST (BEnthic Assessment SedimenT) RIVPACS (River InVertebrate Prediction And Classification Scheme)). Although largely undisturbed, River is affected in some areas by logging, mining, agriculture, pulp mill effluent, urban land use. Overall performance was evaluated using harmonic mean precision, accuracy, measures sensitivity. Invertebrates periphyton were equally accurate precise, but invertebrates more sensitive. Biotic groups least precise classification, also most sensitive had greatest overall performance. BEAST slightly less than RIVPACS, simulated disturbance, real disturbance. Assessments with higher sensitivity frequently lower indicating possible trade-off among these aspects