Australian Institute of Marine Science, Townsville MC, QLD, Australia.
Glob Chang Biol. 2017 Sep;23(9):3869-3881. doi: 10.1111/gcb.13707. Epub 2017 May 9.
Climate change threatens coral reefs across the world. Intense bleaching has caused dramatic coral mortality in many tropical regions in recent decades, but less obvious chronic effects of temperature and other stressors can be equally threatening to the long-term persistence of diverse coral-dominated reef systems. Coral reefs persist if coral recovery rates equal or exceed average rates of mortality. While mortality from acute destructive events is often obvious and easy to measure, estimating recovery rates and investigating the factors that influence them requires long-term commitment. Coastal development is increasing in many regions, and sea surface temperatures are also rising. The resulting chronic stresses have predictable, adverse effects on coral recovery, but the lack of consistent long-term data sets has prevented measurement of how much coral recovery rates are actually changing. Using long-term monitoring data from 47 reefs spread over 10 degrees of latitude on Australia's Great Barrier Reef (GBR), we used a modified Gompertz equation to estimate coral recovery rates following disturbance. We compared coral recovery rates in two periods: 7 years before and 7 years after an acute and widespread heat stress event on the GBR in 2002. From 2003 to 2009, there were few acute disturbances in the region, allowing us to attribute the observed shortfall in coral recovery rates to residual effects of acute heat stress plus other chronic stressors. Compared with the period before 2002, the recovery of fast-growing Acroporidae and of "Other" slower growing hard corals slowed after 2002, doubling the time taken for modest levels of recovery. If this persists, recovery times will be increasing at a time when acute disturbances are predicted to become more frequent and intense. Our study supports the need for management actions to protect reefs from locally generated stresses, as well as urgent global action to mitigate climate change.
气候变化威胁着世界各地的珊瑚礁。近几十年来，强烈的白化现象导致许多热带地区的珊瑚大量死亡，但温度和其他压力源的不那么明显的慢性影响同样对多样化的珊瑚礁系统的长期生存构成威胁。如果珊瑚的恢复速度等于或超过平均死亡率，珊瑚礁就可以持续存在。虽然急性破坏性事件造成的死亡率通常显而易见且易于测量，但估计恢复速度并调查影响恢复速度的因素需要长期承诺。在许多地区，沿海地区的发展正在增加，海水表面温度也在上升。由此产生的慢性压力对珊瑚的恢复产生了可预测的不利影响，但缺乏一致的长期数据集使得难以衡量珊瑚的实际恢复速度发生了多大变化。我们使用澳大利亚大堡礁（GBR）上 10 个纬度跨度的 47 个珊瑚礁的长期监测数据，使用修正后的 Gompertz 方程来估计干扰后的珊瑚恢复速度。我们在两个时期比较了珊瑚的恢复速度：2002 年大堡礁发生广泛的急性热应激事件之前的 7 年和之后的 7 年。从 2003 年到 2009 年，该地区几乎没有发生急性干扰事件，这使我们可以将观察到的珊瑚恢复速度下降归因于急性热应激加上其他慢性压力源的残留影响。与 2002 年之前的时期相比，快速生长的鹿角珊瑚科和“其他”生长较慢的硬珊瑚的恢复速度在 2002 年之后放缓，恢复到适度水平所需的时间增加了一倍。如果这种情况持续下去，那么在急性干扰预计变得更加频繁和强烈的时候，恢复时间将越来越长。我们的研究支持采取管理行动保护珊瑚礁免受本地产生的压力的必要性，以及采取紧急的全球行动缓解气候变化的必要性。
