An eDNA metabarcoding of brittle stars: Examples from the Seto Inland Sea, a semi-closed marine area

Abstract

Marine ecosystem are facing a crisis due to climate change and anthropogenic activities, and many marine organisms are threatened by declining biodiversity. Regular and extensive surveys of these organisms are necessary to conserve the biodiversity. Conventional methods, however, rely on direct observation and collection of specimens by experts with identification and sampling skills. Using environmental DNA (eDNA) metabarcoding methods, we detected a total of 15 brittle star species at two sites in the Seto Inland Sea, a semi-enclosed marine area in Japan. This study showed that brittle stars are useful environmental indicator organisms, and that the eDNA metabarcoding method specific to brittle star is expected to be a useful tool for a wide-ranging and simple investigation method for marine ecosystems. Further investigations will need to verify whether species detected by metabarcoding without being confirmed by direct observations are due to false positives and whether this is due to the semi-enclosed character of the area.