Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China; Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China.
Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou 510301, China.
Sci Total Environ. 2021 Jan 15;752:141866. doi: 10.1016/j.scitotenv.2020.141866. Epub 2020 Aug 21.
Inshore coral habitats are at high risk of loss due to a combination of climate warming and regional-scale human impacts. As a result, they have undergone significant declines. Direct evidence of acute and chronic disturbance on most inshore coral assemblages is limited. Long-term, periodical surveys and historical baseline data essential for effective management are lacking. Using high-precision uranium-thorium (UTh) dating, we reconstruct a ~100-year-long history of extensive coral loss, changes in coral community structure, and a shifting baseline. The data were collected at Weizhou Island, northern South China Sea (SCS), which has highly disturbed inshore coral habitats that are typical globally. According to our UTh dates, major coral mortalities around Weizhou Island have occurred since the 1950s, with increasing frequency and severity since the 1980s. The extensive loss of branching Acropora and collapse of coral communities with peaks around 1960, 1984, and 1998 are accompanied by a shift toward low coral cover and noncoral-dominated assemblages. Prior to this collapse, the local coral community structure sustained remarkable long-term stability over millennia. The timing of the Acropora loss and massive coral mortalities coincides with multiple acute and chronic, natural and anthropogenic disturbance events. We suggest that priority should be given to directly addressing the causes of degradation and effectively controlling chronic disturbances before attempting to restore reef ecosystems. This is probably the only way to solve the "wicked problem" of sustaining the key functions and ecosystem services of inshore coral habitats such as those of Weizhou Island, northern SCS.
由于气候变暖以及区域性人类活动的综合影响，近岸珊瑚生境面临着极高的丧失风险。结果，这些珊瑚生境已经发生了显著的衰退。大多数近岸珊瑚生物群的急性和慢性干扰的直接证据有限。缺乏长期定期调查和历史基线数据，而这些数据对有效管理至关重要。本研究使用高精度铀钍（U-Th）年代测定法，重建了一个长达约 100 年的广泛珊瑚丧失、珊瑚群落结构变化以及基准线转移的历史。这些数据是在南海北部的涠洲岛收集的，该岛拥有高度受干扰的近岸珊瑚生境，这在全球范围内具有典型性。根据我们的 U-Th 年代测定结果，自 20 世纪 50 年代以来，涠洲岛周围发生了多次珊瑚大量死亡事件，自 20 世纪 80 年代以来，其发生频率和严重程度不断增加。广泛的分枝鹿角珊瑚丧失和珊瑚群落的崩溃发生在 1960 年、1984 年和 1998 年左右，同时伴随着珊瑚覆盖率的降低和非珊瑚主导的生物群。在这次崩溃之前，当地珊瑚群落结构在几千年的时间里保持着显著的长期稳定。鹿角珊瑚的丧失和大量珊瑚死亡与多次急性和慢性、自然和人为干扰事件同时发生。我们建议，在试图恢复珊瑚礁生态系统之前，应优先直接解决退化的原因，并有效控制慢性干扰。这可能是解决维持近岸珊瑚生境（如南海北部涠洲岛）关键功能和生态系统服务这一“棘手问题”的唯一途径。
