Water Quality Indicator for Adaptability to Global Climate Change in Andean Highland Ecosystems

In the face of ongoing anthropogenic climate change, river water quality assessment has become increasingly important for maintaining ecological balance and supporting local and downstream livelihoods. This research aims to create a new water quality index (WQI) to assess water quality in the Andean highlands (>2000 m.a.s.l.) for climate change adaptation and mitigation. We examined water physicochemical and bacteriological parameters and the benthic macroinvertebrate (BM) community in three micro-watersheds in Achupallas, Ecuador, to achieve our goal. We analyzed water quality at 41 sampling points, and samples (replicates) were taken for nine consecutive months. In addition, we evaluated the accuracy of the WQI developed by the U.S. National Sanitation Foundation (NSF) in 1970 (WQI_NSF). The BM community in the Andes highlands was used to develop and calibrate a new WQI, the Andean Biotic Index* (ABI*). We calibrated the ABI* taxon score in the area where the WQI_NSF made the most accurate water quality measurements. Our results show that the sigma value framework quantifies WQI_NSF accuracy. Therefore, a higher sigma value means we measured water quality more accurately. There was no correlation between the WQI_NSF and the Andean Biotic Index (ABI). The ABI* considers the presence of BMs and their sensitivity to pollution to measure water quality. The results also show a strong statistical link between the ABI* and the WQI_NSF. The ABI* can aid mountain communities in adjusting to climate change. Mountain dwellers can monitor a stream’s water quality by observing the BM communities. However, the ABI* is not a substitute for the WQI_NSF or biological studies.