EAPSI: Understanding How Coral Reefs in the Ryukyu Islands, Western Pacific Adapted to Changes in the Past Using Paleoecological Analysis

Kovalik Christopher M, Melbourne FL

Investigators

Abstract

With the increasing impacts of global climate change, coral reefs are among the most sensitive ecosystems on the planet. Providing endless goods and services, coral reefs are an integral part of marine ecosystems. Most studies focus on predicting how climate will affect corals in the future. This project will look to the past for insight on how corals handled historic changes in climate by taking coral cores in the Ryukyu Islands of Japan. This research will be conducted in collaboration with Dr. Hironobu Kan at Kyushu University. Dr. Kan will provide necessary equipment for analyses as well as access to the field where cores will be extracted. These 4-m sections of the Holocene reef framework will give a multi-millennial record of reef development in the Western Pacific. The focus of this project will be the window from 4-2 thousand years before present, when a hiatus in reef accretion occurred in others areas of the Pacific. Using a simple, open-barrel, hand-operated coring method, 4-meter cores will be extracted from unconsolidated reefs and further divided into 5 cm intervals. These intervals will be analyzed by species and taphonomic condition to determine the ecological changes on the reef through time. Using a combination of paleoecological and geochemical techniques, a reconstruction of Holocene sea temperature, salinity, coral accretion, and changes in species dominance on the reefs of the Ryukyu Islands during the Holocene will be created. These data will be compared to data collected from cores extracted off Pacific Panama and Kiritimati Island of the Line Islands. This comparison will provide a much clearer understanding of coral growth across the Pacific during the Holocene. Furthermore, this detailed coral-based geochemical reconstruction from the Ryukyu Islands will give insights into how climatic and oceanographic conditions varied through time at this location and how corals have reacted to those changes. These reactions may help estimate how corals will respond to the current global climate changes. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.