Cooperative Institute for Marine and Atmospheric Research, University of Hawai'i, Honolulu, Hawai'i, United States of America.
Pacific Islands Fisheries Science Center, National Marine Fisheries Service, Honolulu, Hawai'i, United States of America.
PLoS One. 2022 Sep 1;17(9):e0269068. doi: 10.1371/journal.pone.0269068. eCollection 2022.
The Hawaiian Archipelago experienced a moderate bleaching event in 2019-the third major bleaching event over a 6-year period to impact the islands. In response, the Hawai'i Coral Bleaching Collaborative (HCBC) conducted 2,177 coral bleaching surveys across the Hawaiian Archipelago. The HCBC was established to coordinate bleaching monitoring efforts across the state between academic institutions, non-governmental organizations, and governmental agencies to facilitate data sharing and provide management recommendations. In 2019, the goals of this unique partnership were to: 1) assess the spatial and temporal patterns of thermal stress; 2) examine taxa-level patterns in bleaching susceptibility; 3) quantify spatial variation in bleaching extent; 4) compare 2019 patterns to those of prior bleaching events; 5) identify predictors of bleaching in 2019; and 6) explore site-specific management strategies to mitigate future bleaching events. Both acute thermal stress and bleaching in 2019 were less severe overall compared to the last major marine heatwave events in 2014 and 2015. Bleaching observed was highly site- and taxon-specific, driven by the susceptibility of remaining coral assemblages whose structure was likely shaped by previous bleaching and subsequent mortality. A suite of environmental and anthropogenic predictors was significantly correlated with observed bleaching in 2019. Acute environmental stressors, such as temperature and surface light, were equally important as previous conditions (e.g. historical thermal stress and historical bleaching) in accounting for variation in bleaching during the 2019 event. We found little evidence for acclimation by reefs to thermal stress in the main Hawaiian Islands. Moreover, our findings illustrate how detrimental effects of local anthropogenic stressors, such as tourism and urban run-off, may be exacerbated under high thermal stress. In light of the forecasted increase in severity and frequency of bleaching events, future mitigation of both local and global stressors is a high priority for the future of corals in Hawai'i.
夏威夷群岛在 2019 年经历了一次中度白化事件——这是在 6 年内第三次对这些岛屿造成重大影响的白化事件。为应对这一情况，夏威夷珊瑚白化合作组织（HCBC）在整个夏威夷群岛进行了 2177 次珊瑚白化调查。HCBC 的成立旨在协调州内各学术机构、非政府组织和政府机构之间的白化监测工作，以促进数据共享并提供管理建议。在 2019 年，该独特合作组织的目标是：1）评估热胁迫的时空模式；2）研究白化易感性的分类群水平模式；3）量化白化程度的空间变化；4）将 2019 年的模式与之前的白化事件进行比较；5）确定 2019 年白化的预测因子；6）探索特定地点的管理策略，以减轻未来的白化事件。与 2014 年和 2015 年的最后两次重大海洋热浪事件相比，2019 年的急性热胁迫和白化总体上较为温和。观察到的白化现象高度依赖于特定地点和分类群，这是由剩余珊瑚群的易感性驱动的，而这些珊瑚群的结构可能受到之前的白化和随后的死亡的影响。一系列环境和人为预测因子与 2019 年观察到的白化现象显著相关。急性环境胁迫因素，如温度和表面光照，与之前的条件（如历史热胁迫和历史白化）同样重要，它们共同解释了 2019 年事件中白化的变化。我们几乎没有发现夏威夷主要岛屿的珊瑚对热胁迫产生适应的证据。此外，我们的研究结果表明，在高温胁迫下，当地人为胁迫因素（如旅游业和城市径流）的不利影响可能会加剧。鉴于预测的白化事件严重程度和频率的增加，减轻当地和全球胁迫因素是保护夏威夷珊瑚的未来的首要任务。
