Historical timescale records of coral growth and skeletal carbonate deposition under conditions of high turbidity and terrigenous sediment influence

高浊度和陆源沉积物影响条件下珊瑚生长和骨骼碳酸盐沉积的历史时间尺度记录

• 批准号: NE/F01077X/1
• 负责人: Christopher Perry
• 金额: $ 8.17万
• 依托单位: Manchester Metropolitan University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF01077X%2F1
• 关键词: Historical; timescale; records; coral; growth

There is a general perception that corals (and coral reefs) are highly susceptible to riverine inputs of terrigenous sediment, and that high rates of such inputs will negatively impact reef health and vitality (usually evidenced by low coral cover and/or high partial mortality rates). In coral reef settings where such inputs have been limited in the past and where corals are not adapted to deal with frequent sediment loading and reduced light penetration, this perception is likely to have considerable validity and may lead, over time, to shifts in coral community structure. However, there is an increasing body of sedimentological, geomorphological and palaeoecological data demonstrating not only long-term (>1,000 year) persistence of coral communities under conditions of high terrigenous sediment input and high turbidity, but also clear evidence of active and rapid reef-accretion. Under these conditions corals seem to be sufficiently adapted to these environmental conditions that coral cover is often high and well-developed reef structures can form. This has been demonstrated at sites in Thailand, Indonesia, Mozambique and at a range of sites along the nearshore (innermost shelf) areas of the Great Barrier Reef (GBR), Australia. An apparent paradox thus exists between the perceived negative effects of high turbidity and terrigenous sediment inputs on coral communities (which are widely referred to in the scientific literature) and the increasing sedimentary and palaeoecological evidence for historical timescale persistence of corals and of reef-building in these settings. This raises an intriguing question about coral carbonate production in these environments and about the nature of skeletal carbonate deposition. Are these coral communities able to produce reef structures, despite high terrigenoclastic sediment input and high turbidity regimes, because of particularly high coral growth and calcification rates? Little data exists from nearshore reefs of this type and there has been no attempt to quantify and compare these processes over temporal and spatial scales. This project thus aims to quantify coral extension (growth) and calcification rates, and to quantify the microskeletal characteristics (i.e., the size and density of key skeletal elements in the coral skeleton) from two of the dominant coral species associated with reef-building within nearshore, turbid-zone settings along the central GBR coastline. The focus for the research will be the two best-studied turbid-zone reefs in the region; Paluma Shoals and Lugger Shoal. Extensive datasets are available on the sedimentary environments, hydrodynamic conditions and contemporary community structures in each locality. In addition, radiocarbon (14C) date-constrained growth models exist for each site that allow data to be placed in a reliable chronological framework. Specifically, we will gather data on a massive coral species (Porites lobata) that makes a major contribution to contemporary reef-flat coral communities in both settings, and a branching coral species (Acropora pulchra) which previous research has demonstrated to have been a major framework contributor throughout the growth history of these reefs. The research will utilise novel Computerised (Axial) Tomography (CT) scanning and established Scanning Electron Microscopy (SEM) approaches to quantify coral growth rates and styles of coral skeletal deposition in these samples. Between-site comparisons will be made against data collected from the same species of Porites and Acropora that were collected from clear water sites at Low Isles during the 1928-1929 Great Barrier Reef Expedition. This extensive and well-catalogued coral repository is stored at the NHM and CT methodologies will allow us to examine the skeletal structures of these corals using non-destructive techniques.

人们普遍认为，珊瑚（和珊瑚礁）高度容易受到陆质沉积物的河流投入的影响，并且这种投入的高率将对珊瑚礁的健康和活力产生负面影响（通常由低珊瑚覆盖率和/或高部分死亡率证明）。在过去的珊瑚礁环境中，这些投入过去曾受到限制，而珊瑚不适合处理频繁的沉积物负荷和降低光穿透性，这种看法可能具有相当大的有效性，并且随着时间的流逝可能导致珊瑚群落结构的转变。然而，在高陆地沉积物输入和高浊度的条件下，珊瑚社区的长期（> 1,000年）的持久性不仅表明了越来越多的沉积学，地貌和古生态数据，而且还表明了活跃和快速礁石的持久性。在这些条件下，珊瑚似乎足以适应这些环境条件，即珊瑚覆盖通常是高且发达的珊瑚礁结构可以形成的。这在泰国，莫桑比克的泰国，澳大利亚大堡礁（GBR）的近岸（最内向的货架）地区的各个地点都证明了这一点。因此，高浊度和陆源沉积物投入对珊瑚社区的负面影响（在科学文献中广泛提及）与在这些情况下珊瑚的历史时间表持久性以及在这些情况下的珊瑚礁建造的历史时间表持续性之间存在明显的悖论。这就提出了一个关于这些环境中碳酸盐产生以及骨骼碳酸盐沉积的性质的有趣问题。尽管珊瑚碎裂的输入高和高浊度，但这些珊瑚群落是否能够产生珊瑚礁结构，因为珊瑚的增长和钙化率特别高？这种类型的近海礁很少存在，并且没有尝试在时间和空间尺度上量化和比较这些过程。因此，该项目旨在量化珊瑚扩展（生长）和钙化速率，并量化来自两个主要的珊瑚种类的微型骨骼特征（即珊瑚骨骼中关键骨骼骨骼中关键的骨骼骨骼的大小和密度），与近岸境内的珊瑚礁建造相关，沿GBR沿着中央GBR海岸线沿着中央的浊度设置。该研究的重点将是该地区的两个最佳的浑浊区珊瑚礁。 Paluma浅滩和Lugger浅滩。在每个地方的沉积环境，流体动力学条件和当代社区结构上都有广泛的数据集。此外，每个站点都存在放射性碳（14C）约会约束的生长模型，允许将数据放置在可靠的年代框架中。具体而言，我们将收集有关大型珊瑚物种（Porites lobata）的数据，该数据在两种环境中对当代珊瑚礁 - 弗拉特珊瑚群落和分支珊瑚种类（Acropora pulchra）做出了重大贡献，而先前的研究已证明在这些礁石的整个生长历史中都证明是主要框架的主要框架。该研究将利用新型的计算机化（轴向）层析成像（CT）扫描，并建立的扫描电子显微镜（SEM）方法来量化这些样品中珊瑚生长速率和珊瑚骨骼沉积样式。将在1928 - 1929年在大岛大岛的大​​岛大岛礁探险期间从相同物种的孔子和Acropora收集的数据进行比较。这个广泛且良好的珊瑚储存库存储在NHM，CT方法论将使我们能够使用非破坏性技术检查这些珊瑚的骨骼结构。

项目成果

Mid-Holocene sea surface conditions and riverine influence on the inshore Great Barrier Reef

• DOI: 10.1177/0959683614534739
• 发表时间: 2014-06
• 期刊: The Holocene
• 作者: R. Roche;C. Perry;S. Smithers;M. Leng;C. Grove;H. Sloane;Catherine Unsworth

Recurrent patterns of coral community and sediment facies development through successive phases of Holocene inner-shelf reef growth and decline

全新世内陆架礁生长和衰退的连续阶段中珊瑚群落和沉积相发育的循环模式

• DOI: 10.1016/j.margeo.2011.09.012
• 发表时间: 2011
• 期刊: Marine Geology
• 影响因子: 2.9
• 作者: Perry C

Evidence for the episodic "turn on" and "turn off" of turbid-zone coral reefs during the late Holocene sea-level highstand

全新世晚期海平面高位期间浑浊带珊瑚礁间歇性“开启”和“关闭”的证据

• DOI: 10.1130/g30444.1
• 发表时间: 2010
• 期刊: Geology
• 影响因子: 5.8
• 作者: Perry C

Spatial variation in porosity and skeletal element characteristics in apical tips of the branching coral Acropora pulchra (Brook 1891)

分支珊瑚 Acropora pulchra 顶端孔隙度和骨骼元素特征的空间变化（Brook 1891）

• DOI: 10.1007/s00338-010-0679-1
• 发表时间: 2010
• 期刊: Coral Reefs
• 影响因子: 3.5
• 作者: Roche R