Coral reefs are among the most biologically diverse and complex marine ecosystems on Earth. However, anthropogenic impacts continue to degrade coral reefs worldwide, potentially increasing the ability for localized climatic irregularities or fluctuations to cause rapid changes to habitats over limited spatial scales. Bora-Bora Island was impacted by one such irregularity between 02^th and January 05, 2020, with adjacent reefs subjected to a combination of low tides, high temperature and algal bloom. Our monitoring surveys showed that after only four days of these conditions, live coral cover on some Bora-Bora reefs rapidly declined from 80 ± 7% to 20 ± 7%. In addition, the density of fishes and giant clams also decreased (i.e., respectively, from 3.6 to 6.1 individuals per m² before climatic anomaly to 2.6 and 2.2 individuals after climatic anomaly). This study suggests that, as the mean environmental conditions continue to move towards to abiotic limits on coral reef growth and persistence, even small fluctuations above these limits could have dramatic impacts on the resilience of reef communities.

珊瑚礁是地球上生物多样性最丰富，最复杂的海洋生态系统之一。然而，人为影响继续在全球范围内使珊瑚礁退化，潜在地提高了局部气候不规则或波动的能力，从而在有限的空间尺度上引起了栖息地的快速变化。在2020年2月2^日至1月5日期间，波拉波拉岛受到一个这样的不规则影响，相邻的礁石受到低潮，高温和藻华的综合影响。我们的监测调查显示，仅在这种情况发生四天后，某些波拉波拉岛礁上的活珊瑚覆盖率迅速从80±7％下降至20±7％。此外，鱼类和大蛤的密度也降低了（即分别从每m ² 3.6到6.1个体气候异常之前的2.6和2.2个人）。这项研究表明，随着平均环境条件继续朝着对珊瑚礁生长和持久性的非生物限制的方向发展，即使这些限制之上的微小波动也可能对珊瑚礁群落的复原力产生巨大影响。