Globally, many coral reefs have fallen into negative carbonate budget states, where biological erosion exceeds carbonate production. The compounding effects of urbanization and climate change have caused reductions in coral cover and shifts in community composition that may limit the ability of reefs to maintain rates of vertical accretion in line with rising sea levels. Here we report on coral reef carbonate budget surveys across seven coral reefs in Singapore, which persist under chronic turbidity and in highly disturbed environmental conditions, with less than 20% light penetration to 2 m depth. Results show that mean net carbonate budgets across Singapore’s reefs were relatively low, at 0.63 ± 0.27 kg CaCO 3 m −2 yr −1 (mean ± 1 SE) with a range from − 1.56 to 1.97, compared with the mean carbonate budgets across the Indo-Pacific of 1.4 ± 0.15 kg CaCO 3 m −2 yr −1 , and isolated Indian Ocean reefs pre-2016 bleaching (~ 3.7 kg CaCO 3 m −2 yr −1 ). Of the seven reefs surveyed, only one reef had a net negative, or erosional budget, due to near total loss of coral cover (< 5% remaining coral). Mean gross carbonate production on Singapore’s reefs was dominated by stress-tolerant and generalist species, with low-profile morphologies, and was ~ 3 kg m −2 yr −1 lower than on reefs with equivalent coral cover elsewhere in the Indo-Pacific. While overall these reefs are maintaining and adding carbonate structure, their mean vertical accretion potential is below both current rates of sea level rise (1993–2010), and future predictions under RCP 4.5 and RCP 8.5 scenarios. This is likely to result in an increase of 0.2–0.6 m of water above Singapore’s reefs in the next 80 yr, further narrowing the depth range over which these reefs can persist.

中文翻译：

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在高度城市化的环境中增加珊瑚礁

在全球范围内，许多珊瑚礁已陷入碳酸盐负预算状态，生物侵蚀超过碳酸盐产量。城市化和气候变化的复合效应导致珊瑚覆盖范围减少和群落组成发生变化，这可能会限制珊瑚礁在海平面上升时保持垂直增长速度的能力。在这里，我们报告了新加坡七个珊瑚礁的珊瑚礁碳酸盐预算调查，这些珊瑚礁在长期混浊和高度干扰的环境条件下持续存在，2 m 深度的光穿透率低于 20%。结果表明，与整个新加坡珊瑚礁的平均碳酸盐预算相比，新加坡珊瑚礁的平均净碳酸盐预算相对较低，为 0.63 ± 0.27 kg CaCO 3 m -2 yr -1（平均值 ± 1 SE），范围从 - 1.56 到 1.97印太 1.4±0。15 kg CaCO 3 m -2 yr -1 ，以及 2016 年之前孤立的印度洋珊瑚礁白化（~ 3.7 kg CaCO 3 m -2 yr -1 ）。在调查的七个珊瑚礁中，由于珊瑚覆盖几乎完全丧失（剩余珊瑚少于 5%），只有一个珊瑚礁出现净负或侵蚀预算。新加坡珊瑚礁的平均碳酸盐总产量主要由具有低剖面形态的耐压和多面性物种主导，并且比印度-太平洋其他地方具有同等珊瑚覆盖的珊瑚礁低约 3 kg m -2 yr -1 。虽然总体上这些珊瑚礁正在维持和增加碳酸盐结构，但它们的平均垂直增生潜力低于当前海平面上升速率（1993-2010）以及 RCP 4.5 和 RCP 8.5 情景下的未来预测。这很可能导致未来 80 年新加坡珊瑚礁上方的水位增加 0.2-0.6 m，