Collaborative Research Ocean Acidification: Establishing the links between offshore biogeochemistry, coral reef metabolism and acidification

合作研究海洋酸化：建立近海生物地球化学、珊瑚礁代谢和酸化之间的联系

• 批准号: 1416518
• 负责人: Andreas Andersson
• 金额: $ 42.95万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1416518&HistoricalAwards=false
• 关键词: Collaborative; Research; Ocean; Acidification; Establishing

Time-series observations from the Atlantic and Pacific Oceans have revealed indisputable evidence of long-term acidification of open-ocean surface seawater due to uptake of anthropogenic carbon dioxide from the atmosphere. Concurrent evidence of negative effects of acidification on the production and preservation of calcium carbonate have fueled concern about the potential consequences to coral reefs. Although long-term acidification in coral reef environments in general has not been observed, seawater acidification rates on the Bermuda coral reef platform between 2007-2012 have been found to be three times faster than the long-term (1983-2012) acidification rate observed at a nearby offshore open-ocean time-series station. The investigators on this project believe that they now understand how this happens and have designed a study to confirm or refute their ideas. Specifically they believe that the observed changes in 2007-2012 are attributable to a recent shift in reef metabolic processes associated with an increase in net reef calcification and heterotrophy. The evidence they have in-hand suggests that these changes have been fueled by an increase in food supply to the reef as a result of increased offshore primary production seemingly linked to the state of the North Atlantic Oscillation (NAO), a periodic back-and-forth shifting of atmospheric pressure differences between the subpolar and the subtropical North Atlantic. In this project, by collecting an extensive set of physical, chemical, and biological data extending from the reef platform at Bermuda to the offshore open-water time-series station, they will explore this idea. The primary scientific and societal broader impacts of this project will be its relevance to advancing current understanding of the effects of ocean acidification on coral reefs. Robust prediction of future effects on this ecosystem requires knowledge of the main drivers of reef biogeochemical processes and of local seawater acidification. Secondly, the project will support the education and research activities of both graduate and undergraduate students working as members of the research team, and foster community educational outreach through the Ocean Discovery Institute in San Diego and the Ocean Academy in Bermuda to engage students from underrepresented minorities. The central hypothesis of this research is that during years of negative winter NAO, intensified mixing and increased nutrient supply enhance offshore production leading to coral reef calcification and reef heterotrophy, thus intensifying the local seawater acidification on the reef. To address this hypothesis, the team will measure and characterize inshore seawater biogeochemical properties (temperature, salinity, dissolved inorganic carbon, total alkalinity, calcium, partial pressure of carbon dioxide, inorganic nutrients, particulate organic carbon and nitrogen, total organic carbon and nitrogen, phytoplankton pigments, and bacterial abundance) on a monthly interval across the Bermuda coral reef. These data will be evaluated in concert with data collected as part of the Bermuda-Atlantic Time-Series and Hydrostation S programs and along inshore-offshore transects. It is expected that this approach will further the understanding of how seawater biogeochemical properties, including seawater carbonate chemistry, vary over time and space on the Bermuda coral reef, and identify the main drivers of these variations. It will specifically address the coupling between offshore and inshore biogeochemical processes and how they are linked to larger-scale oceanographic and climatic forcings, such as the NAO. It also addresses how reef biogeochemical processes may alleviate or exacerbate ocean acidification, and whether these changes are important to reef metabolism in the context of other forcings such as light, nutrients, and food availability.

对大西洋和太平洋的时间序列观测显示，无可争议的证据表明，由于从大气中吸收人为二氧化碳，公海表层海水长期酸化。同时，酸化对碳酸钙的生产和保存产生负面影响的证据引发了对珊瑚礁潜在后果的担忧。 虽然尚未观察到珊瑚礁环境总体上的长期酸化，但已发现2007-2012年期间百慕大珊瑚礁平台上的海水酸化速度比在附近一个离岸公海时间序列站观察到的长期（1983-2012年）酸化速度快三倍。 该项目的研究人员认为，他们现在了解了这种情况是如何发生的，并设计了一项研究来证实或反驳他们的想法。 具体而言，他们认为，2007-2012年观察到的变化可归因于最近与净珊瑚礁钙化和异养增加相关的珊瑚礁代谢过程的转变。 他们手头的证据表明，这些变化是由于珊瑚礁食物供应的增加而推动的，这是由于离岸初级生产的增加似乎与北大西洋涛动（NAO）的状态有关，这是一种周期性的来回移动。在这个项目中，通过收集从百慕大的珊瑚礁平台到近海开放水域时间序列站的大量物理、化学和生物数据，他们将探索这一想法。 这一项目的主要科学和社会影响将是其与促进目前对海洋酸化对珊瑚礁影响的认识的相关性。要对这一生态系统的未来影响进行可靠的预测，就需要了解珊瑚礁生物地球化学过程和当地海水酸化的主要驱动因素。第二，该项目将支持研究生和本科生作为研究小组成员开展教育和研究活动，并通过圣地亚哥海洋发现研究所和百慕大海洋学院促进社区教育外联活动，让代表人数不足的少数群体的学生参与。 本研究的中心假设是，在冬季NAO为负的年份，加强混合和增加营养物质供应增强了近海生产，导致珊瑚礁钙化和礁异养，从而加剧了当地海水酸化的珊瑚礁。为了解决这一假设，该小组将每月一次测量和确定百慕大珊瑚礁沿岸海水生物地球化学特性（温度、盐度、溶解无机碳、总碱度、钙、二氧化碳分压、无机营养物、颗粒有机碳和氮、总有机碳和氮、浮游植物色素和细菌丰度）。 这些数据将与作为大西洋-大西洋时间序列和水电站S方案的一部分收集的数据以及沿着近海-近海断面收集的数据一起进行评价。 预计这一方法将进一步了解百慕大珊瑚礁的海水生物地球化学性质，包括海水碳酸盐化学性质如何随时间和空间变化，并确定这些变化的主要驱动因素。它将专门讨论近海和近海生物地球化学过程之间的耦合，以及它们如何与更大规模的海洋和气候强迫（如NAO）联系起来。它还讨论了珊瑚礁生物地球化学过程如何缓解或加剧海洋酸化，以及这些变化是否对珊瑚礁在其他强迫因素（如光、营养物质和食物供应）的背景下的新陈代谢很重要。

项目成果

Lateral, Vertical, and Temporal Variability of Seawater Carbonate Chemistry at Hog Reef, Bermuda

百慕大猪礁海水碳酸盐化学的横向、垂直和时间变化

• DOI: 10.3389/fmars.2021.562267
• 发表时间: 2021
• 期刊: Frontiers in Marine Science
• 影响因子: 3.7
• 作者: Pezner, Ariel K.;Courtney, Travis A.;Page, Heather N.;Giddings, Sarah N.;Beatty, Cory M.;DeGrandpre, Michael D.;Andersson, Andreas J.
• 通讯作者: Andersson, Andreas J.