Coral reefs on the tin island of Belitung: ‘reefs of hope’ threatened by pollution and runoff (TINBELT)

印度尼西亚是世界上最大的群岛国家，拥有世界上约18%的珊瑚礁。人类对珊瑚礁生态系统服务的依赖是世界上最高的。然而，印度尼西亚是一个快速发展的国家，珊瑚礁受到陆地污染的影响，影响到其珊瑚礁的多样性和珊瑚覆盖。此外，印度尼西亚的珊瑚礁受到全球海洋表面温度上升的威胁，这是由人为造成的大气二氧化碳上升造成的。异常高的海表温度造成热应力事件，导致珊瑚漂白和死亡，在不久的将来会越来越频繁。关于珊瑚礁衰退的最大科学不确定性之一是当地人类的影响，如沿海污染，如何与全球气候变化相互作用。传统观点认为，原始的珊瑚礁更容易受到珊瑚白化的影响。然而，这一点最近受到了挑战，因为沿海污染有利于珊瑚，而珊瑚对水温升高也更敏感。勿里洞岛（印度尼西亚）是检验这两个假设的理想地点。该岛是东南亚锡矿带的一部分，自19世纪60年代以来一直在开采锡。沿海径流和污染长期影响着勿里洞的珊瑚礁。近岸珊瑚礁生长在浑浊的水中，以大型圆顶状的滨珊瑚为主，它们比分支珊瑚更能承受径流、污染和热应力。TINBELT的目标是：（I）在受采矿活动影响的两个地点，沿沿着到前礁断面监测珊瑚覆盖和海水化学;（II）利用长寿的滨珊瑚监测近岸和外礁环境的水质（河川径流：Ba/Ca;无机地球化学：采矿活动）;（III）重建加速上升的海表温度自1970年以来，在珊瑚礁规模使用珊瑚Sr/Ca比和（IV）调查珊瑚最近的热应力事件，使用CT图像和微量元素签名的反应。历史和全新世珊瑚样本被用来确定自然变异的基线。该项目的一部分将致力于为新型LA-ICP-OES和LASS-ICP-OES/ICP-MS分流模式制定分析协议，这将大大推进对珊瑚礁污染和温度相关压力的研究。TINBELT解决了SPP 2299（主题B）的一个主要目标：随着时间的推移，温度上升和海洋酸化等大规模压力源如何与当地压力源（河流径流，营养负荷，污染）相互作用？

Indonesia is the largest archipelagic nation in the world and harbors approximately 18 percent of the world’s coral reefs. Human dependence on coral reef ecosystem services is highest in the world. However, Indonesia is a rapidly developing country and reefs are impacted by land-based pollution which affects the diversity and coral cover of its coral reefs. In addition, Indonesia’s coral reefs are threatened by the global rise in sea surface temperatures (SSTs) driven by the anthropogenic rise in atmospheric CO2. Anomalously high SSTs cause thermal stress events leading to coral bleaching and mortality with increasing frequency in the near future. One of the greatest scientific uncertainties concerning the decline of coral reefs is how local human impacts, such as coastal pollution, interact with global climate change. The conventional view is that pristine coral reefs are more robust to coral bleaching. However, this has been challenged recently based on the observation that coastal pollution favors corals that are also more robust to elevated water temperatures. Belitung Island (Indonesia) is an ideal site to test these two hypotheses. The island is part of the SE Asian tin belt, and tin has been mined since the 1860s. Coastal runoff and pollution has affected Belitung’s coral reefs over long periods of time. Near-shore coral reefs grow in turbid water and are dominated by large, dome-shaped Porites corals, which are more robust to runoff, pollution and thermal stress than branching corals. TINBELT aims to (I) monitor coral cover and seawater chemistry along near-shore to fore-reef transects at two sites impacted by mining activities; (II) use long-lived Porites corals to monitor water quality in inshore and outer reef settings over time (river runoff: Ba/Ca; inorganic geochemistry: mining activities); (III) reconstruct the accelerated rise of SSTs since 1970 at the reef-scale using coral Sr/Ca ratios and (IV) investigate the corals response to recent thermal stress events using CT images and trace element signatures. Historical and Holocene coral samples are used to establish baselines of natural variability. Part of the project will be dedicated to the development of analytical protocols for the novel LA-ICP-OES and the LASS-ICP-OES/ICP-MS in split-stream mode, which should significantly advance studies on pollution and temperature-related stress in coral reefs. TINBELT addresses a major goal the SPP 2299 (Topic B): How do large-scale stressors such as rising temperatures and ocean acidification interact with local stressors (river runoff, nutrient loads, pollution) over time?