Abstract
Freshwater ecosystems in the Indo-Burma biodiversity hotspot face immediate threats through habitat loss and species extinction. Systems to monitor ecological status and trends in biodiversity are therefore crucially needed. Myanmar is part of Indo-Burma but with no past experience of biomonitoring in freshwaters. In this study, we aimed to assess the ecological and biodiversity status of a lowland river network in south-central Myanmar by identifying and quantifying pressures using macroinvertebrates as bioindicators. Novel data on water quality (nutrients, sediments and metals), hydromorphology (Morphological Quality Index; MQI), habitat quality (Litter-Siltation Index; LSI), land use, and macroinvertebrates were collected from 25 river sites. The dominant pressures on rivers were urban land use, inputs of untreated sewage, in-stream and riparian garbage littering, run-off from agricultural fields and plantations, as well as physical habitat degradation. Water chemistry data indicated inputs of sediments and nutrients to degraded streams, but no obvious metal pollution. The LSI and MQI indices indicated high perturbation in agricultural and urban areas, respectively. Ecological status was assessed using a first version of a modified Average Score per Taxon index (ASPT), while biodiversity was assessed by family richness within the orders Ephemeroptera, Plecoptera, Trichoptera, Coleoptera and Odonata (EPTCO), which was tested against the pressure gradient by principal component regressions. ASPT had high diagnostic capabilities (R2 = 0.68, p < 0.001) and showed that the index can be used to evaluate ecological water quality in this region. Biodiversity, expressed as family richness, also declined along the gradient (R2 = 0.59, p = 0.041), giving support to the fact that current land-use practices in this area are unsustainable.
Highlights
Southeast Asia is known for an exceptionally high rate of biodiversity and endemism but is one of the most biologically threatened regions worldwide (Brooks et al, 2002; Hughes, 2017; Myers et al, 2000)
Ecological status was assessed using a first version of a modified Average Score per Taxon index (ASPT), while biodiversity was assessed by family richness within the orders Ephemeroptera, Plecoptera, Trichoptera, Coleoptera and Odonata (EPTCO), which was tested against the pressure gradient by principal component regressions
Apart from some biomonitoring initiated by the Mekong River Commission in the lower Mekong River and its tributaries, including Cambodia, Lao PDR, Thailand and Vietnam, there is to our knowledge no biomonitoring programs for rivers in Indo-Burma
Summary
Southeast Asia is known for an exceptionally high rate of biodiversity and endemism but is one of the most biologically threatened regions worldwide (Brooks et al, 2002; Hughes, 2017; Myers et al, 2000). We explore threats to freshwaters and management options in a river network in Myanmar, a part of the Indo-Burma biodiversity hotspot (Myers et al, 2000) with no history of biomonitoring, and where the ecological and biodiversity status of surface waters is largely unknown. Ecological sta tus evaluations, per the EU WFD, are primarily based on bioindicators (biological quality elements; BQE), such as fish, algae, macrophytes and macroinvertebrates, which are supported by physical and chemical pa rameters. The use of these parameters is desirable in the management strategies for Myanmar, but with little previous experience in biomonitoring, it is necessary to develop the appropriate tools. Apart from some biomonitoring initiated by the Mekong River Commission in the lower Mekong River and its tributaries, including Cambodia, Lao PDR, Thailand and Vietnam, there is to our knowledge no biomonitoring programs for rivers in Indo-Burma
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
