EAPSI: Identifying Octocoral-Symbiont Associations in Okinawa, Japan

Buccella Louis A, West Seneca NY

Investigators

Abstract

Okinawa, Japan, is host to many diverse soft corals (octocorals) that by and large rely on symbiotic algae for survival. These algae, known as Symbiodinium, live within the tissue of the host coral. Okinawan octocorals are largely understudied, and in some species, the host coral's associated symbionts have yet to be identified. Corals are threatened by a variety of factors, many of which induce a breakdown of this symbiosis (known as coral bleaching), which can result in the death of the coral. Following the approximate 50% loss of all Indo-Pacific coral cover since the 1980's, there is a greater need to identify Symbiodinium diversity, as not all symbiont types are equally susceptible to environmental threats. This study aims to examine unknown diversity by identifying the Symbiodinium populations associated with these understudied octocorals around Okinawa, a location of particular interest because it is the northernmost distribution limit for many of these species. This work will be done at the Molecular Invertebrate Systematics and Ecology Lab at the University of the Ryukyus in Okinawa, Japan, in collaboration with Dr. James Reimer, whose expertise with both Japanese octocorals and Symbiodinium will be a big asset. With the use of SCUBA and/or snorkeling, octocorals from a range of genera will be identified and sampled from locations surrounding Okinawa, specified by Dr. Reimer and his lab members. The endosymbiont Symbiodinium communities will then be identified using a series of molecular markers, beginning with analyses of the ribosomal internal transcribed spacer regions (ITS2 types), using protocols in which Dr. Reimer helped develop. Since it is predicted that these species will be dominated by Symbiodinium type C1, chloroplast psbAncr and possibly microsatellite flanking regions will then be analyzed to maximize the level of resolution within type C1. This survey will serve as a guide for future research, where it can be used as a baseline for comparisons and could even have the potential to aid in predicting certain species distributions/survivorship under ongoing climate change impacts such as global warming. This award, under the East Asia and Pacific Summer Institutes program ,supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.