eDNA data set from 63 locations of Okinawa Island

Coral reefs have the highest biodiversity of any marine ecosystem in tropical and subtropical oceans. However, scleractinian corals, keystone organisms of reef productivity, are facing a crisis due to climate change and anthropogenic activities. A broad survey of reef-building corals is essential for world-wide reef preservation. To this end, direct observations made by coral-specialist divers can be supported by a more convenient method. We improved a recently devised environmental DNA (eDNA) metabarcoding method to identify more than 43 scleractinian genera by sampling 2 L of surface seawater above reefs. Together with direct observations by divers, we assessed the utility of eDNA at 63 locations spanning ~250 km near Okinawa Island. Slopes of these islands are populated by diverse coral genera, whereas shallow “moats” sustain fewer and less varied coral taxa. Major genera recorded by divers included Acropora, Pocillopora, Porites, and Montipora, the presence of which was confirmed by..., (a) Sampling
Reef monitoring was conducted at 63 coral reef locations in the latter half of 2021 by simultaneous diving observations of corals and collection of surface seawater above these reefs. Names of monitored locations, survey dates, geomorphic classification, latitude, longitude, types of coral community, and major coral genera observed are summarized in electronic supplementary materials, table S1, figure 1, and figure S1. Most locations were reef slopes, 3–10 m in depth, and some were inner reef edge moats, 1–3 m in depth (figure 1; electronic supplementary material, table S1).
Two experienced coral-reef specialists snorkeled around reefs and recorded coral community types and dominant coral genera (species), according to the conventional Monitoring Sites 1000 Project conducted annually by the Ministry of the Environment of Japan (https://www.biodic.go.jp/moni1000/manual/spot-check_ver5.pdf). Types of coral community included “multi-species mixed”, “specific species”, and “no...,