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

随着全球气候变化的影响越来越大，珊瑚礁是地球上最敏感的生态系统之一。珊瑚礁提供无穷无尽的商品和服务，是海洋生态系统不可分割的一部分。大多数研究都集中在预测气候对未来珊瑚的影响。这个项目将着眼于过去，以日本琉球群岛的珊瑚核为例，深入了解珊瑚如何应对气候的历史性变化。这项研究将与九州大学的Hironobu Kan博士合作进行。菅直人博士将提供必要的分析设备，以及进入将提取岩心的现场。这段4米长的全新世珊瑚礁框架将记录西太平洋几千年来的珊瑚礁发育。该项目的重点将是距今4-2000年前的窗口，当时太平洋其他地区的珊瑚礁增长出现了间歇期。使用一种简单的开桶手动取心方法，将从松散的生物礁中提取4米长的岩芯，并进一步划分为5厘米的间隔。这些间隔将根据物种和割胶条件进行分析，以确定珊瑚礁随时间的生态变化。利用古生态和地球化学技术的结合，将重建全新世琉球群岛珊瑚礁上全新世的海温、盐度、珊瑚沉积和物种优势变化。这些数据将与从太平洋巴拿马和莱恩群岛基里蒂马蒂岛附近提取的岩心收集的数据进行比较。这种比较将使我们更清楚地了解全新世期间太平洋上珊瑚的生长情况。此外，琉球群岛基于珊瑚的详细地球化学重建将深入了解该地点的气候和海洋条件如何随时间变化，以及珊瑚如何对这些变化做出反应。这些反应可能有助于估计珊瑚将如何应对当前的全球气候变化。该NSF EAPSI奖是与日本科学促进会合作资助的。

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.