摘要:Abstract The eDNA Society was founded in Japan in 2018 to develop eDNA science as a discipline that contributes to the human well‐being and the sustainable use of ecosystems. Since then, the society has expanded attracting a wide variety of people from international universities, research institutes, consultant companies, and local/national governments. Here we report edna2021, the fourth annual meeting of The eDNA Society, which was held mainly online on November 20–21, 2021. We had c.a. 500 participants in total, from at least 15 countries. In the meeting, we discussed not only the technical aspects of environmental DNA but also its potential for various applications including its combinations with environmental RNA, sediment core samples, population genetic analyses, etc.