DEVELOPMENT, CALIBRATION AND VALIDATION OF AN INDEX OF BIOTIC INTEGRITY FOR THE WABASH RIVER

摘要: Fish assemblage data were collected using daytime electrofishing during 1993-2001 from 275 river reaches found throughout the Interior River Lowland and Eastern Corn Belt Plain ecoregions to construct, test, apply an index of biotic integrity (IBI). The was developed a rapid as- sessment procedure that used assess environmental quality large great ecosystems in state. reference condition based on sites representative Wabash River, but not pristine or least-impacted. These randomly chosen, met specific least- impacted criteria develop IBI. We another 36 exposed point-source discharges test index. Prior sampling, classified as "least-impacted" affected by point source pollution industrial discharges. Of 24 potential IBI metrics considered, 12 chosen statistical relevance for rivers. For subset, least-impacted had significantly higher mean scores lower temporal variation than site classification, showing they possessed best ecosystem quality. Point-source lowest means most variable scores, signifying degraded Least-impacted highest variability, while typical agricultural land uses slightly worse scores. Regional estimates stream conditions showed 42% ecoregion fish assemblages poor fair ecological condition, large-river 36% 23% good.