eDNA metabarcoding of coral spawning slicks

Quantifying the community composition of coral spawning slicks is challenging, with current methods being resource-intensive and limited in scope. Here, we tested the performance of two coral ITS primer sets, CoralITS2 and CoralITS2_acro, on mock communities to evaluate their ability to capture genera composition and relative abundances. Both primer sets demonstrated high accuracy in detecting and quantifying coral taxa in mock community samples. Subsequently, these primers were applied to wild-collected spawning slicks from the Great Barrier Reef, revealing variation in their community composition. Our findings underscore the potential of eDNA-based assays as a scalable, non-invasive tool to confirm the presence and relative abundance of diverse coral assemblages in natural slicks, informing restoration and monitoring efforts.