Monitoring natural ecological communities is often time-, labour-, and money-consuming work. DNAs that are derived from organisms and remain in natural environments (environmental DNA eDNA) have been used to detect presence/absence of organisms and to estimate abundance/biomass of target organisms. To facilitate the use of eDNA as a tool to monitor ecological communities, further developments of eDNA techniques are necessary. To archive this goal, this project aims to improve and develop techniques for DNA extractions, amplifications and sequencing.