RII Track-4: NSF: Novel target-enriched genomic approaches to assess the diversity of Gorgonian Octocorals on Indo-Pacific Mesophotic Coral Reefs

University Of Hawaii, Honolulu

Investigators

Abstract

This RII Track-4 Research Fellowship will investigate the diversity of gorgonian octocorals from shallow to mesophotic depths of the Indo-Pacific. The coral reefs of the Indo-Pacific are centres of marine biodiversity, yet the natural resilience and biodiversity of these ecosystems are under great threat. Research at deeper depths (mesophotic coral ecosystems - MCEs; 30 to >150 m) reveal an unknown reservoir of biodiversity and natural resilience in the face of steep environmental gradients. Gorgonian octocorals typically dominate these dynamic environments yet are notoriously difficult to identify in the field and from morphological traits alone. Furthermore, molecular phylogenies have been largely unresolved, until the recent pioneering research of the project host at the National Museum of Natural History (NMNH), using target-capture genomics. This research will apply these novel genomic approaches to the PI’s rare and highly unique gorgonian collection from the mesophotic and shallow reefs of the Indo-Pacific that she has assembled over several years. Applying these novel genomic approaches to the PI’s collections will move beyond current analytical limitations and add transformative data and phylogenetic accuracy to the Cnidarian tree of life. This fellowship will assist the PI in building capacity at the University of Hawai‘i at Mānoa by passing on these critical and innovative skills, particularly to underrepresented minority students who are native to the locations of the samples themselves, and are passionate to conserve marine biodiversity of national and international concern. Gorgonian octocorals are an ecologically important, highly diverse yet poorly resolved group, where traditional markers have lacked phylogenetic resolution at the species and higher taxonomic level. Delimiting species and species boundaries across steep environmental clines are critically important in biodiversity assessments for conservation management particularly as the value of mesophotic ecosystems is increasingly recognised. Thus, we test the hypotheses that 1) the gorgonian fauna is distinct and more diverse at mesophotic depths, and 2) that morphotypes within the ubiquitous genus Annella Gray, 1858, are delimited by depth. This will be achieved using the target-capture genomic approach developed by the host, which simultaneously estimates the phylogenetic relationships between taxa over shallow and deep time, population structure within a species, and the delimitation of species boundaries. Using these methods will facilitate the development of a multi-trait (phenotypic and genomic) framework that will 1) assess the phylogenetic and phylogeographic relationships within and between gorgonian taxa from shallow to mesophotic depths, and 2) present an exemplar case study of population structure and species delimitation in the widely distributed genus, Annella Gray, 1858. This work will develop a multi-trait (morphologic and genomic) framework to advance our understanding of a critically important coral group from some of the world’s most biodiverse yet critically endangered hotspots. This research will provide the opportunity for the PI and a female graduate assistant from a Pacific coastal nation, to learn these highly effective genomic techniques that are specific to corals, and disseminate the results formally (e.g., peer-review publication, MCE Gordon Research Conference) and informally (e.g., social media platforms). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.