Abstract Scattered evidence indicates the occurrence of coral thermal bleaching events during the mid-Holocene. However, information on such occurrences is still very rare. Ten Porites coral cores were drilled from the Wenchang fringing reef of Hainan Island, northern South China Sea. These cores contain mortality surfaces and/or growth discontinuities dating from the mid-late Holocene between 3.4 and 5.7 thousand years ago (ka, before 1950 AD). Monthly Sr/Ca, δ18O and δ13C were analyzed to reconstruct sea-surface temperature (SST), sea-surface salinity (SSS), and photosynthesis intensity during the events. Results show that the mortality surfaces and growth discontinuities of five corals are associated with high SST of 30.3 °C–33.6 °C and high SSS of 34.3–38.3. The abrupt concurrent negative shifts of 1.8‰ or more in δ13C indicate a decrease in the photosynthesis intensity, most likely attributable to the loss of zooxanthellae. These lines of evidence imply that the mortality surfaces and growth discontinuities were the consequence of coral bleaching under abnormally high temperature. The observed recovery directly after bleaching events indicates that corals in the South China Sea are capable of rehabilitation after experiencing severe environmental stresses.

中文翻译：

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南海北部全新世中晚期 Porites 珊瑚周期性白化和恢复的新证据

摘要 零星的证据表明在全新世中期发生了珊瑚热漂白事件。然而，关于此类事件的信息仍然非常罕见。在南海北部海南岛文昌岛礁上钻探了 10 个 Porites 珊瑚核。这些核心包含死亡面和/或生长不连续性，其历史可以追溯到 3.4 至 5700 年前（公元 1950 年之前）的全新世中晚期。每月分析 Sr/Ca、δ18O 和 δ13C，以重建事件期间的海面温度 (SST)、海面盐度 (SSS) 和光合作用强度。结果表明，5 种珊瑚的死亡面和生长不连续性与 30.3°C-33.6°C 的高 SST 和 34.3-38.3 的高 SSS 相关。1 的突然并发负偏移。δ13​​C 大于或等于 8‰表明光合作用强度下降，很可能是由于虫黄藻的损失。这些证据表明，死亡表面和生长不连续是异常高温下珊瑚白化的结果。在漂白事件后直接观察到的恢复表明，南海的珊瑚在经历严重的环境压力后能够恢复。