Short?term temporal variation of coastal marine eDNA

Temporal variation in eDNA signals is increasingly explored for understanding community ecology aquatic habitats. Seasonal changes have been addressed using sampling, but very little known regarding short-term temporal that spans hours to days. To address this, we filtered marine water samples from a single coastal site Denmark every hour 32 h. We used metabarcoding target both fish and broader eukaryote diversity evaluated this community. Results revealed species richness (15–27) class (35–64) across the h of further sampling efforts needed reach different levels saturation. Relative read frequency data eukaryotes indicated clear diel change composition, with communities detected during daylight versus dark hours. The abundance our reflected biological rather than stochastic variation, since replicates taken at same were more similar each other those Our compositional results dynamic community, static pool eDNA—even few showed daily pattern relative abundances, uncoupling suggest profiles day can provide valuable information reflecting changes, least highly mobile organism groups. However, also point several pitfalls current experimental design, which are over large areas without time-consistency or replication. findings shed new light on wide implications study design incorporating temporality into project conceptualization future biodiversity monitoring.