Postdoctoral Fellowship: OCE-PRF: Quantifying the effects of ocean alkalinity enhancement on costal ecosystems and atmospheric carbon dioxide

过去两年，科技行业对二氧化碳去除技术的投资迅速增加，加速了海洋碱度增强（OAE）公司的成立，这些公司已经在自然生态系统中发挥作用。然而，我们对橄榄石溶解对大气二氧化碳（CO2）的认识仍处于起步阶段。此外，没有研究量化橄榄石诱发的OAE对OAE试验点底栖珊瑚礁群落的影响。本提案的目标是描述OAE对珊瑚礁底栖生物和水中微生物群落功能的影响，以设计一个测量、报告和核查的框架。该提案将通过恒化实验、天然橄榄石海滩实地调查和生物地球化学模型来评估对环境和大气二氧化碳的潜在影响。可控的恒化实验将能够直接测量橄榄石溶解产物，包括次生矿物沉淀及其对珊瑚礁群落动态的影响。提出的研究将有助于理解：1)量化橄榄石在生态相关海水系统中的溶解速率；2)大气CO2通量和速率对橄榄石OAE的响应；4)对珊瑚礁群落功能的影响。尽管多项研究已经确定了可能的脱靶效应，例如产生有毒镍以及改变颗粒相关的微生物群落组成。在创建更多的OAE公司并开始影响这些重要的珊瑚礁生态系统之前，必须对这些不确定性和生态系统的影响进行量化。本研究旨在：1)表征OAE对主要底栖生物、相关微生物群落和溶解有机质循环的影响；2)量化珊瑚礁生态系统中橄榄石的溶解速率和由此导致的大气CO2的减少；3)建立生物地球化学-水动力耦合模型，预测开放海洋系统中橄榄石OAE的效果，量化区域尺度上的大气CO2去除；4)为OAE的测量、验证和报告制定新的方法和标准。这项工作有可能在OAE领域取得变革性进展，并指导这一新兴行业的规模扩展，使其能够在不影响其他重要生态系统的情况下捕获最多的大气二氧化碳。该项目解决了美国国家科学院、工程院和医学院面临的挑战：开发OAE的经验框架，评估方法与环境影响之间的关系，开发稳健的测量、报告和验证策略。由于有效实施AOE迫切需要数据和准确的模型，所有数据、实地研究和模型将在任何数据可用之前通过github存储库随时可用。本项目由GEO/OCE博士后奖学金计划和EPSCoR （Established Program to incentive Competitive Research）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Rapidly increasing investment over the past two years into carbon dioxide removal technologies from the tech industry has accelerated the creation of ocean alkalinity enhancement (OAE) companies which are already acting in natural ecosystems. However, our understanding of olivine dissolution on atmospheric carbon dioxide (CO2) is still in its infancy. Moreover, no studies have quantified the impact of olivine induced OAE on the benthic reef communities which populate the OAE test sites. The goal of this proposal is to characterize the effects of OAE on the functioning of the coral reef benthos and water microbial community to design a framework for measurement, reporting and verification. This proposal will evaluate the potential impacts on both the environment and atmospheric CO2, through chemostat experiments, field surveys of natural olivine beaches and biogeochemical modeling. Controlled chemostat experiments will enable direct measurement of the olivine dissolution products including secondary mineral precipitation and their effect on reef community dynamics. The proposed research will contribute novel, fundamental knowledge to understand: 1) quantification of the dissolution rate of olivine in an ecologically relevant seawater system; 2) flux and rate of atmospheric CO2 in response to olivine OAE; 4) impact on coral reef community function. Although multiple studies have identified plausible off-target effects such as the creation of toxic nickel as well as shifting the particle-associated microbial community composition. Before more OAE companies are created and begin impacting these vital reef ecosystems, these uncertainties and ecosystem impacts must be quantified. This proposal aims to: 1) characterize the impact of OAE on dominant reef benthic primary producers, their associated microbial communities, and dissolved organic matter cycling; 2) quantify olivine dissolution rate in reef ecosystems and the resultant drawdown of atmospheric CO2; 3) develop a biogeochemical-hydrodynamic coupled model to predict the efficacy of olivine OAE in open-ocean systems and quantify atmospheric CO2 removal on a regional scale; 4) develop new methodologies and criteria for measurement, verification and reporting for OAE. This work has the potential to make transformative advances in OAE and guide the scaling of this new industry to systems which are best equipped to capture the most atmospheric CO2 without impacting other vital ecosystems. This project addresses challenges addressed in the National Academies of Sciences, Engineering, and Medicine: Development of an empirical framework for OAE, Assessment of the relationship between approach and environmental impact development of robust measurement, reporting, and verification strategies. Due to the immediate need of data and accurate models for effective implementation of AOE, all data, field studies, and models will be readily available through a github repository as soon as any data becomes available, prior to publication.This project is jointly funded by GEO/OCE Postdoctoral Fellowships Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.