“HKH screening”: a field bio-assessment to evaluate the ecological status of streams in the Hindu Kush-Himalayan region

A macro-invertebrate-based field screening method for assessing the ecological status of rivers in the Hindu Kush-Himalayan Region is presented herein. The method was developed within an EU-funded project called “Development of an Assessment System to Evaluate the Ecological Status of Rivers in the Hindu Kush-Himalayan Region (ASSESS-HKH)”. The data originate from five countries: Bangladesh, Bhutan, India, Nepal, and Pakistan. The main instrumental method used was a screening protocol based on the Austrian method for screening the ecological quality of rivers and streams. The conception of the method, its adoption to the conditions in the Hindu Kush-Himalayan Region, and the application of the protocol are described comprehensively. The assessment procedure was based on sensory criteria and biota that can be identified in the field, with a special focus on benthic macro-invertebrates. The basic principles of benthic bio-indicators’ assortment are described. The determination of individual bio-indicative values is demonstrated for selected examples. An NMS analysis was performed to describe the intra- and inter-similarities of benthic invertebrate assemblages in streams of different eco-regions. As a result, two different HKH screening protocols are provided: one for rivers in mountainous regions and one for lowland rivers. The performance of the screening method in the region and its validation as a rapid, cost-effective, and scientifically based tool for river quality assessment is discussed.