Using benthic macro invertebrates to assess water quality in 15 watersheds in the pacific northwest, usa

Many government entities have focused on methods to monitor the biological integrity of aquatic ecosystems to address impacts of non-point source pollution. The purpose of this is to determine stream macro invertebrate index (SMI) scores throughout Idaho and to relate these values to observed soil erosion rates and visual estimates of stream water quality. This study took place over a 15-year period. Based on benthic macro invertebrate sampling, water quality ranged from very good to very poor at the 124 sampling sites in 15 Idaho watersheds. Strong, significant relationships were observed between SMI water quality ratings and observed soil erosion rates. Sites with soil erosion rates of