Bivalve shell-based, high-resolution multi-proxy reconstruction of marine primary production – Pecten maximus, Bay of Brest

基于双壳类贝壳的高分辨率多代理海洋初级生产重建 - 大扇贝，布雷斯特湾

• 批准号: 406350147
• 负责人: Professor Dr. Bernd R. Schöne
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/406350147?language=en
• 关键词: Bivalve; shell; based; resolution; multi

Primary producers form the basis of marine food webs, control population sizes at higher trophic levels and fish stock recruitment. Marine photoautotrophic organisms are also responsible for nearly half of the global net primary production, i.e., they replenish the ocean (and atmosphere) with oxygen and fix substantial amounts of carbon. Despite its outstanding relevance for the functioning of marine ecosystems and global climate, past primary production dynamics and mechanisms controlling them are not well characterized. This is particularly true for nearshore coastal environments and for times prior to significant human perturbation of biogeochemical cycles. Available data sources for changes in marine primary production (i) do not provide the necessary temporal resolution to resolve short-lived and spatially restricted phytoplankton blooms, specifically in shallow waters, (ii) are too short to distinguish trends from low-frequency cycles of primary production and (iii) do not cover the entirety of photoautotroph taxa which include more than just phytoplankton and cyanobacteria, i.e. microphytobenthos and macroalgae. Therefore, this project will develop an innovative technique that can provide reliable, temporally well-constrained, seasonally to inter-annually resolved data on past primary production dynamics in coastal nearshore environments based on shells of bivalve mollusks. For this purpose, we will test and refine existing proxies (surrogates) for primary production, and develop new proxies and integrate them in a multiproxy approach. In order to obtain a mechanistic understanding of how information on the species composition and number of marine photoautotrophs is recorded in chemical properties (Ba/Ca, Mo/Ca, Li/Ca, stable isotopes of carbon and nitrogen, triple isotope composition of oxygen, pigments) and color (hue and saturation index) of the shells, field and tank experiments will be conducted during which environmental variables can be closely monitored and manipulated. Since the study involves experiments with living bivalves we chose the fast-growing species, Pecten maximus, and an ecosystem that has been studied in great detail, the Bay of Brest, France.The multiproxy approach will subsequently by applied to subfossil shells collected from an archaeological site to determine the human impact on primary production dynamics of the Bay of Brest including (i) the seasonal occurrence of photoautotrophs as well as the intensity, frequency and seasonal timing of phytoplankton blooms, (ii) shifts in species composition and biomass through time and (iii) changes in the link between organisms inhabiting the sea floor and those living near sea surface. Results of this study will significantly advance marine sciences including paleoecology, paleoclimatology and fisheries sciences.

初级生产者构成海洋食物网的基础，控制较高营养水平的种群规模和鱼类资源补充。海洋光自养生物还负责全球近一半的净初级产量，即它们向海洋（和大气）补充氧气并固定大量碳。尽管它与海洋生态系统和全球气候的功能具有突出的相关性，但过去的初级生产动态和控制它们的机制并没有很好地表征。对于近岸海岸环境和在人类对生物地球化学循环进行重大干扰之前的时代尤其如此。关于海洋初级生产变化的现有数据来源(i)没有提供必要的时间分辨率，以解决浮游植物的短期和空间限制的繁殖问题，特别是在浅水区；（ii）太短，无法区分初级生产的低频周期趋势；（iii）没有涵盖整个光自养分类群，其中不仅包括浮游植物和蓝藻，即微型底栖植物和大型藻类。因此，该项目将开发一种创新技术，该技术可以提供可靠的、时间约束良好的、季节性到年际的、基于双壳类软体动物壳的沿海近岸环境中过去初级生产动态的解决数据。为此，我们将测试和改进用于初级生产的现有代理（代理），并开发新的代理并将它们集成到多代理方法中。为了从机制上了解海洋光自养生物的种类组成和数量信息是如何记录在贝壳的化学性质（Ba/Ca、Mo/Ca、Li/Ca、碳和氮的稳定同位素、氧的三重同位素组成、颜料）和颜色（色调和饱和度指数）上的，将进行现场和水族箱实验，在此期间可以密切监测和操纵环境变量。由于这项研究涉及到活体双壳类动物的实验，我们选择了快速生长的物种，Pecten maximus，以及一个已经被详细研究过的生态系统，法国布雷斯特湾。多代理方法随后将应用于从考古遗址收集的亚化石壳，以确定人类对布列斯特湾初级生产动态的影响，包括(i)光自养生物的季节性发生以及浮游植物繁殖的强度、频率和季节时间；（ii）物种组成和生物量随时间的变化；（iii）生活在海底的生物与生活在海面附近的生物之间联系的变化。这一研究成果将对包括古生态学、古气候学和渔业科学在内的海洋科学产生重大的推动作用。