Land Use and Water Quality in Bangladesh and Bhutan

The freshwater systems of Bhutan and Bangladesh offer marked contrasts in anthropogenic disturbance, surrounding land uses, watershed population density, and benthic macroinvertebrate ecology. However, they share a lack of published research on water quality monitoring, specifically in regard to biological monitoring with benthic macroinvertebrates. With their high diversity, high abundance, and spectrum of pollution tolerances, benthic macroinvertebrates are an inexpensive yet powerful tool for monitoring freshwater health. In November of 2015, the Stroud Water Research Center performed physical, chemical, microbiological, and macroinvertebrate sampling at 18 stream sites in western Bhutan, with sites representing a variety of surrounding land uses and disturbance levels. In August of 2016, the author and fellow Penn MES student Naimul Islam performed a second round of sampling at fourteen sites in Bhutan, and a first round of sampling at ten sites in Bangladesh, using both quantitative collection techniques as well as less technical citizen-science techniques. After extraction and identification to the taxonomic level of family, macroinvertebrate taxa were compared across land uses and in relation to collected physico-chemical and microbiological metrics. In Bhutan, significant changes in macroinvertebrate taxa were correlated with changes in upstream versus downstream condition, as well as with monsoon versus postmonsoon sampling times. In Bangladesh, the citizen-science collection technique of leaf packs selected overwhelmingly for Chironomidae and thus could not distinguish between upstream and downstream conditions, necessitating an in-field or lab modification of the technique for future use. Given each country's direct interests in maintaining clean, functioning freshwater systems, both Bangladesh and Bhutan – and much of South Asia – are ripe for the implementation of both citizen-science and technical biomonitoring techniques that connect communities and public officials to measures of water quality and stream condition.