Center for Environment & Water, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
Center for Environment & Water, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
Sci Total Environ. 2021 Jan 1;750:142254. doi: 10.1016/j.scitotenv.2020.142254. Epub 2020 Sep 15.
The Arabian Gulf is a natural laboratory for examining the consequences of large-scale disturbances due to global warming on coral reef ecosystems because of its extreme temperature regime. Using a coral reef monitoring time series extending from 1985 to 2015, we examined the long-term ecological changes in fish and macro-invertebrate communities as these habitats suffered heat shocks. We used a GLMM modelling framework to obtain clean annual signals in community indicators from noisy data. We also visualized temporal change in the taxonomic composition of fishes and macro-invertebrates. A phase shift from predominantly reef-building corals to barren grounds occurred between 1996 and 2000. Macro-invertebrates responded rapidly, and most of associated indicators recovered to pre-shift levels in 15 years. Fishes generally had lagged responses to the phase shift and had shifted to a new state with lower abundance, as well as different species composition. Increased levels of herbivory first by macro-invertebrates, mostly sea urchins, and then fishes, could have suppressed macro-algae expansion and consequently led to the dominance of barren ground. When the phase shift occurred, most of the 14 fish families declined in abundance while macro-invertebrate groups increased. Fish families able to utilize non-coral habitats appeared more resilient to the disturbances and subsequent coral degradation. Unlike other regions, we observed high resilience of the coral-dependent butterflyfishes to coral loss, possibly due to local migration from other less-impacted coral reefs. We hypothesized a top-down control mechanism mediated by predation by fishes has contributed to shaping the temporal and spatial patterns of the macro-invertebrates. Our results also revealed differences in spatial preferences among fishes and macro-invertebrate groups, which could be used to set priorities and develop effective conservation and management strategies.
阿拉伯海湾是一个天然实验室，可以研究由于全球变暖导致的大规模干扰对珊瑚礁生态系统的影响，因为该地区的极端温度对珊瑚礁的影响很大。我们利用从 1985 年到 2015 年的珊瑚礁监测时间序列，研究了这些生境遭受热冲击时鱼类和大型无脊椎动物群落的长期生态变化。我们使用 GLMM 建模框架从嘈杂的数据中获得群落指标的清晰年度信号。我们还可视化了鱼类和大型无脊椎动物的分类组成的时间变化。从 1996 年到 2000 年，主要由造礁珊瑚组成的生境发生了从珊瑚礁到荒地的相位转变。大型无脊椎动物反应迅速，大多数相关指标在 15 年内恢复到转变前的水平。鱼类对相位转变的反应通常滞后，并通过新的状态转移到一个生物量较低的状态，以及不同的物种组成。首先是大型无脊椎动物（主要是海胆），然后是鱼类，增加了食草性，这可能抑制了大型藻类的扩张，从而导致了荒地的主导地位。当相位转变发生时，大多数鱼类家庭的丰度下降，而大型无脊椎动物群体增加。能够利用非珊瑚生境的鱼类家庭似乎对干扰和随后的珊瑚退化更具弹性。与其他地区不同，我们观察到依赖珊瑚的蝴蝶鱼对珊瑚丧失具有很高的恢复力，这可能是由于从其他受影响较小的珊瑚礁本地迁移而来。我们假设一种由鱼类捕食介导的自上而下的控制机制促成了大型无脊椎动物的时空模式。我们的研究结果还揭示了鱼类和大型无脊椎动物群体之间的空间偏好差异，这可以用来确定优先事项，并制定有效的保护和管理策略。
