Accretion patterns of Belize barrier and atoll reefs: an archive of environmental change during the Holocene

伯利兹堡礁和环礁的增生模式：全新世环境变化档案

• 批准号: 461264545
• 负责人: Professor Dr. Eberhard Gischler
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/461264545?language=en
• 关键词: Accretion; patterns; Belize; barrier; atoll

The status of tropical coral reefs has been declining due to warming, ocean acidification, pollution, and disease (Pandolfi et al. 2003, 2011; Hughes et al. 2017; Eyre et al. 2018). This is also visible in reefs of the Caribbean realm in that live coral cover has diminished (Gardner et al. 2003), many reefs are no longer dominated by corals but fleshy algae (Hughes 1994), reef-building acroporid and massive faviid corals are reduced in abundance and replaced by weedy, generalistic taxa (Perry et al. 2015; Kuffner and Toth 2016), and reef accretion potential has decreased (Perry et al. 2018). As millions of people are living along tropical coasts and on reef islands and because these people are dependent on coral reefs socio-economically, this issue is not purely scientific. The study of drill core material extracted from modern coral reefs allows detailed reconstructions of environmental conditions during the Holocene based on sedimentological, paleoecological, and geochronological analyses. Based on these data, previous ecological and environmental changes can be reconstructed that may allow to decide whether or not current declines are unprecedented and serve also as basis for future predictions. It is proposed to revisit existing core material from Belize barrier and atoll reefs, the largest reef system in the Atantic, and to perform additional age dating to constrain patterns of reef accretion, date faunal changes, and identify possible reef gaps. This will be achieved by quantitatively analyzing reef composition and by obtaining some 50 new U/Th-dates from corals in 22 drill cores (total Holocene length 213.4 m) and to add these to 58 existing age dates. As a valuable side-effect, the regional Holocene sea-level curve of Belize can be refined based on the new age data.

由于气候变暖、海洋酸化、污染和疾病，热带珊瑚礁的状况一直在下降（Pandolfi等人，2003年，2011年; Hughes等人，2017年; Eyre等人，2018年）。这在加勒比海地区的珊瑚礁中也很明显，活珊瑚覆盖面积已经减少（Gardner等人，2003年），许多珊瑚礁不再由珊瑚而是肉质藻类主导（Hughes 1994），造礁的顶孔珊瑚和巨大的鸟粪珊瑚的数量减少，取而代之的是杂草丛生的一般分类群（佩里等人，2015年; Kuffner和Toth，2016年），并且珊瑚礁增生潜力已经下降（佩里等人，2018年）。由于数百万人生活在沿着热带海岸和珊瑚礁岛上，而且由于这些人在社会经济上依赖珊瑚礁，这个问题不纯粹是科学问题。从现代珊瑚礁中提取的钻芯材料的研究允许在沉积学，古生态学和地质年代学分析的基础上详细重建全新世的环境条件。根据这些数据，可以重建以前的生态和环境变化，从而可以确定当前的下降是否是前所未有的，并作为未来预测的基础。建议重新研究来自伯利兹堡礁和环礁礁（Atantic最大的珊瑚礁系统）的现有核心材料，并进行额外的年龄测定，以限制珊瑚礁增生的模式，确定动物群变化的日期，并确定可能的珊瑚礁缺口。这将通过定量分析珊瑚礁的组成，并通过获得约50个新的U/Th-日期从珊瑚在22个钻芯（全新世总长度213.4米），并将这些添加到58个现有的年龄。作为一个有价值的副作用，伯利兹的区域全新世海平面曲线可以根据新的年龄数据进行细化。