Quantifying rates and trends in endolithic bioerosion on coral reefs

项目背景热带珊瑚礁生态系统不仅维持着高水平的生物多样性，而且提供了许多直接造福社会的生态系统商品和服务。其中一些商品和服务有很好的记录，可以随着可靠性的提高而量化(例如，粮食资源供应、海岸保护)。然而，碳酸盐产砂率的量化要差得多--这一过程受到珊瑚礁生态的强烈影响，因为大多数珊瑚礁沉积物来自珊瑚礁上生活的动植物，例如，作为鹦鹉鱼和海胆觅食的副产品，来自软体动物和有孔虫等骨骼生物，以及来自分泌碳酸盐的藻类，如Halimeda。关于这些生产者在珊瑚礁上产生沉积物的速度的数据一般很少，尤其是与不同类型的珊瑚礁环境有关的数据，因为它们的环境条件和珊瑚礁群落组成不同。这是一个重大的知识差距，因为在礁石上产生的沉积物质的数量和等级(大小)影响珊瑚礁的生长，对近海海滩和岛屿的建造是必不可少的。包括鹦鹉鱼在内的大量珊瑚礁物种在礁石上产生碳酸盐沉积物方面发挥着关键作用。项目目标和方法本项目的目的是对沉积物生成速率进行参数化，然后应用方法来量化沉积物生成速率，特别是西澳大利亚(WA)的偏远礁-礁岛屿系统。该项目将建立在最近的方法的基础上，这些方法已经试行了基于生态普查方法的量化沉积物产生的方法(Perry等人)。2015、2017、2019年)，也开始探索干扰事件对生态驱动的沙子生产的影响(Perry等人)。2020)。学生将首先建立一套经验数据集，以量化一系列产生沉积物的珊瑚礁物种(鹦鹉、海胆、哈利米达、有孔虫)在西澳一系列清水和浑浊珊瑚礁上的生物产沙率(目的是包括埃克斯茅斯湾和宁格鲁珊瑚礁的地点)。该项目的这一阶段将包括测试基于人工智能的工具，以支持对珊瑚礁沉积物的自动分析，以量化底栖有孔虫等常见生产者组的丰度。然后，将使用生成的数据集来量化和绘制这些地点的人口普查数据中的珊瑚礁级别的沙子生成率。已知底栖生态和环境条件(光、浊度、温度、波能)在这些珊瑚礁系统之间存在显著差异，因此，我们假设，珊瑚礁沉积的速率和来源也会有显著差异。因此，该项目将大大增加我们目前对生态驱动的珊瑚礁沉积物生成率的有限了解和量化能力--这是支持加强沿海和礁岛脆弱性建模所需的数据。项目合作伙伴除了美国埃克塞特大学的导师(克里斯·佩里教授和伊内斯·兰格博士)外，学生还将由两个外部学术合作伙伴共同监督。Ken Johnson博士(伦敦自然历史博物馆)过去曾与主管Chris Perry在婆罗洲和东澳大利亚混浊地带珊瑚礁的生态学和沉积学方面进行过广泛的合作。除了他在浑浊珊瑚礁方面的专业知识外，他还将在基于人工智能的沉积物分析方面提供支持。这名学生还将与科廷大学海外导师尼基·布朗博士领导的团队密切合作，该团队已在研究系统的生态方面开展了广泛的工作，并将支持拟议中的西澳实地考察工作。

Project BackgroundTropical coral reef ecosystems sustain not only high levels of biodiversity, but also provide numerous ecosystem goods and services that directly benefit society. Some of these goods and services are well documented and can be quantified with increasing reliability (e.g., food resource provisioning, coastal protection). However, far more poorly quantified are rates of carbonate sand production - a process strongly influenced by reef ecology because most reef sediment derives from the fauna and flora living on reefs e.g., as a by-product of parrotfish and urchin feeding, from skeletal organisms such as molluscs and foraminifera, and from carbonate-secreting algae such as Halimeda. Data on the rates at which these producers generate sediment on reefs is generally sparse, and is especially poorly understood in relation to different types of reef settings that differ in their environmental conditions and reef community composition. This is a major knowledge gap because the quantity and grade (size) of sedimentary material produced on reefs impacts upon reef growth and is essential for proximal beach and island building.Numerous reef species, including parrotfish, play a key role in generatingcarbonate sediment on reefs.Project Aims and MethodsThe aim of this project is to parameterise and then apply methodologies for quantifying sediment generation rates, with a specific focus on remote reef-reef islands systems in Western Australia (WA). The project will build on recent approaches that have piloted methods for quantifying sediment generation based on ecological census approaches (Perry et al. 2015, 2017, 2019), and which have also started to explore the influence of disturbance events on ecologically-driven sand production (Perry et al. 2020). The student will firstly establish a set of empirical datasets to quantify rates of biological sand production for a range of sediment producing reef species (parrotfish, sea urchins, Halimeda, foraminifera) across a range of both clear-water and turbid reefs of WA (the intention being that this will include sites in Exmouth Gulf and on Ningaloo Reef). This phase of the project will include testing of AI-based tools to support auto-analysis of reef sediments for quantifying the abundance of common producers groups such as benthic foraminifera. Resultant datasets will then be used to quantify and map reef-level sand generation rates from census data across these sites. Benthic ecology and environmental conditions (light, turbidity, temperature, wave energy) are known to differ markedly between these reef systems and thus so too, we hypothesise, will rates and sources of reef-derived sediment. This project will thus add significantly to our currently limited understanding of, and capacity to quantify, rates of ecologically-driven reef sediment generation - data that is needed to support enhanced coastal and reef island vulnerability modelling. Project partners In addition to the U. Exeter based supervisors (Prof Chris Perry & Dr Ines Lange) the student will be co-supervised by two external academic partners. Dr Ken Johnson (Natural History Museum, London) has worked extensively in the past with supervisor Chris Perry on the ecology and sedimentology of turbid-zone coral reefs in Borneo and Eastern Australia. In addition to his expertise on turbid reefs he will offer support on the AI-based sediment analysis. The student will also work closely with the team led by overseas supervisor Dr Nikki Browne at Curtin University, whose group have undertaken wide ranging work on the ecology of the study systems and will support the proposed fieldwork in WA.