Coral reef ecosystems protect coastlines, sequester carbon, and provide food by supporting extensive fisheries, that produce distinct molecules for human medicine. Despite their importance, the organisms largely responsible for these ecosystem services have remained undetected due to weaknesses in conventional biodiversity census methods. This study estimated the biodiversity of these cryptic coral reef taxa using a passive and standardized sampling tool called autonomous reef monitoring structures or ARMS. In doing so, we mapped the diversity of eukaryotes, bacteria, and chemicals over more than seven thousand miles of the Indo-Pacific, spanning an area known as the Coral Triangle, which is home to the highest diversity of conspicuous taxa on Earth. Amplicon-based gene sequencing of the organisms that colonized ARMS identified ~83-87% of known marine phyla and discovered thousands of novel taxa. These results dramatically expand the known biodiversity of coral reefs and reveal that much reef biodiversity remains to be explored. Similarly, only 0.6% of the chemical compounds detected on ARMS could be identified, less than the 1.8% average identification rate of hundreds of thousands of natural samples, showing that the dearth of knowledge about chemical diversity in nature is particularly great on coral reefs. Most chemical compounds were only produced in a single location, revealing an unexpected biochemical value (e.g., novel pharmaceutical discovery) of both high and low biodiversity coral reefs. This project generated substantial value for academic research by providing standardized guidelines for applying ARMS and demonstrating the effectiveness of this technology as a census tool. This product is particularly timely given that ARMS are now being implemented by researchers worldwide, including outside of coral reefs. The ability of ARMS to capture most known and substantial amounts of unknown coral reef biodiversity suggests they may provide a powerful tool for reef conservation. Given these results, this tool is now being used as a way to seed degraded coral reefs with beneficial fauna. This project taught fundamental science and cutting-edge laboratory techniques (e.g., next generation genetic sequencing) to nearly one hundred underrepresented minority undergraduates in the United States and a similar number of international student collaborators (e.g., Indonesia, the Philippines). These educational efforts were carried out via field research in tropical locations and laboratory research at multiple American universities and spanned multiple summer months. Ten postdoctoral researchers and 20 graduate students received training as part of this project.

Last Modified: 02/04/2020
Modified by: Forest Rohwer