Utility of an existing biotic score method in assessing the stream health in Bhutan

In many countries water quality is assessed by using indices derived from the presence of macroinvertebrate species. This study aimed to improve the application of one such index (Hindu-Kush Himalaya based index: HKHbios) to rivers and streams in Bhutan. Sampling in a number of different streams showed that there was a strong influence of the monsoon on stream macroinvertebrates, however the month to month and site to site HKHbios scores showed no consistent patterns. Dry season sampling and increased ecological information on a number of macroinvertebrate taxa were identified as areas where water quality assessment in Bhutanese streams could be improved.