Marine Ecology Department, Faculty of Biology and Chemistry, University of Bremen, Leobener Straße 6, 28359, Bremen, Germany.
Institute for Ecology, Faculty of Biology and Chemistry, University of Bremen, Leobener Straße 5, 28359, Bremen, Germany.
Sci Rep. 2020 Oct 12;10(1):17034. doi: 10.1038/s41598-020-74077-x.
Documenting post-bleaching trajectories of coral reef communities is crucial to understand their resilience to climate change. We investigated reef community changes following the 2015/16 bleaching event at Aldabra Atoll, where direct human impact is minimal. We combined benthic data collected pre- (2014) and post-bleaching (2016-2019) at 12 sites across three locations (lagoon, 2 m depth; seaward west and east, 5 and 15 m depth) with water temperature measurements. While seaward reefs experienced relative hard coral reductions of 51-62%, lagoonal coral loss was lower (- 34%), probably due to three-fold higher daily water temperature variability there. Between 2016 and 2019, hard coral cover did not change on deep reefs which remained dominated by turf algae and Halimeda, but absolute cover on shallow reefs increased annually by 1.3% (east), 2.3% (west) and 3.0% (lagoon), reaching, respectively, 54%, 68% and 93% of the pre-bleaching cover in 2019. Full recovery at the shallow seaward locations may take at least five more years, but remains uncertain for the deeper reefs. The expected increase in frequency and severity of coral bleaching events is likely to make even rapid recovery as observed in Aldabra's lagoon too slow to prevent long-term reef degradation, even at remote sites.
记录珊瑚礁群落的去白化轨迹对于了解它们对气候变化的恢复能力至关重要。我们调查了阿尔达布拉环礁在 2015/16 年白化事件后的珊瑚群落变化，该地区受直接人为影响较小。我们结合了在三个地点（泻湖，2 米深；西部和东部海域，5 米和 15 米深）的 12 个地点在白化前（2014 年）和白化后（2016-2019 年）收集的底栖数据，以及水温测量数据。虽然向海的珊瑚礁经历了相对硬珊瑚减少 51-62%，但泻湖的珊瑚礁损失较低（-34%），这可能是由于那里的日水温变化率高出三倍。在 2016 年至 2019 年期间，深礁上的硬珊瑚覆盖面积没有变化，这些深礁仍然以草坪藻类和 Halimeda 为主，但浅礁上的硬珊瑚绝对覆盖面积每年增加 1.3%（东部）、2.3%（西部）和 3.0%（泻湖），分别在 2019 年达到白化前覆盖面积的 54%、68%和 93%。在浅向海地区，完全恢复可能至少还需要五年时间，但深层珊瑚礁的恢复情况仍不确定。珊瑚白化事件的频率和严重程度预计会增加，即使像在阿尔达布拉泻湖那样快速的恢复速度也可能太慢，无法防止长期的珊瑚礁退化，即使是在偏远地区。
