King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal, 23955-6900, Saudi Arabia.
The Red Sea Development Company, 5th Floor, MU04 Tower, ITCC Complex, AlRaidah Digital City, Al Nakhil District 3807, Riyadh, 12382-6726, Saudi Arabia.
Sci Rep. 2022 Oct 9;12(1):16944. doi: 10.1038/s41598-022-21304-2.
The combination of molecular tools, standard surveying techniques, and long-term monitoring programs are relevant to understanding environmental and ecological changes in coral reef communities. Here we studied temporal variability in cryptobenthic coral reef communities across the continental shelf in the central Red Sea spanning 6 years (three sampling periods: 2013-2019) and including the 2015 mass bleaching event. We used a combination of molecular tools (barcoding and metabarcoding) to assess communities on Autonomous Reef Monitoring Structures (ARMS) as a standardized sampling approach. Community composition associated with ARMS for both methodologies (barcoding and metabarcoding) was statistically different across reefs (shelf position) and time periods. The partition of beta diversity showed a higher turnover and lower nestedness between pre-bleaching and post-bleaching samples than between the two post-bleaching periods, revealing a community shift from the bleaching event. However, a slight return to the pre-bleaching community composition was observed in 2019 suggesting a recovery trajectory. Given the predictions of decreasing time between bleaching events, it is concerning that cryptobenthic communities may not fully recover and communities with new characteristics will emerge. We observed a high turnover among reefs for all time periods, implying a homogenization of the cryptobiome did not occur across the cross shelf following the 2015 bleaching event. It is possible that dispersal limitations and the distinct environmental and benthic structures present across the shelf maintained the heterogeneity in communities among reefs. This study has to the best of our knowledge presented for the first time a temporal aspect into the analysis of ARMS cryptobenthic coral reef communities and encompasses a bleaching event. We show that these structures can detect cryptic changes associated with reef degradation and provides support for these being used as long-term monitoring tools.
分子工具、标准测量技术和长期监测计划的结合对于了解珊瑚礁群落的环境和生态变化是相关的。在这里，我们研究了 6 年间（三个采样期：2013-2019 年）红海中部大陆架上的隐生珊瑚礁群落的时间变化，包括 2015 年的大规模白化事件。我们使用分子工具（条形码和代谢组学）组合来评估自治式珊瑚礁监测结构（ARMS）上的群落，作为标准化采样方法。两种方法（条形码和代谢组学）的 ARMS 相关群落组成在不同的珊瑚礁（大陆架位置）和时间段上存在统计学差异。β多样性的划分显示，在白化前后的样本之间，周转率较高，嵌套性较低，而在两个白化后时期之间，周转率较低，嵌套性较高，这表明群落从白化事件中发生了转移。然而，2019 年观察到了向白化前群落组成的轻微回归，表明存在恢复轨迹。考虑到白化事件之间时间间隔减少的预测，隐生生物群落可能无法完全恢复，而具有新特征的群落将会出现，这令人担忧。我们观察到所有时间段内的群落周转率都很高，这意味着在 2015 年白化事件后，隐生生物群并没有在整个大陆架范围内发生同质化。可能是由于扩散限制以及大陆架上存在的独特环境和底栖结构，维持了各珊瑚礁之间的群落异质性。据我们所知，本研究首次从时间角度分析了 ARMS 隐生珊瑚礁群落，并涵盖了白化事件。我们表明，这些结构可以检测到与珊瑚礁退化相关的隐式变化，并为将其用作长期监测工具提供了支持。
