EXPLORATION OF FILTERING AND CONCENTRATION METHODS TOWARDS APPLICATIONS OF ENVIRONMENTAL DNA TO TURBID WATER

Abstract

 Environmental DNA (eDNA) method, a novel technique for precise and expeditious biological surveillance, has been widely used for monitoring population dynamics and safeguarding wild animals such as rare species. However, eDNA has rarely been applied to turbid water environments, and thus, surveillance method for turbid water has not been established. In this study, we explored applicability of environmental DNA method to rivers under various turbid conditions targeting Cyprinus carpio. Turbid water collected from the three rivers bearing different land-use in the catchments was processed based on the two different filtering methods either using a grass fiber filter (pore size = 0.7 µm) or prefilteration (20 µm) before processing with the grass fiber filter. Under highly turbid conditions, conventional grass fiber-based filtering method could not process 1 L even using two filter papers for many samples while it exhibited greater concentration of eDNA than the prefilteration method. None of suspended solids or ash free dry mass was associated with eDNA concentration.