Will high CO2 conditions affect production, partitioning and fate of organic matter?

高二氧化碳条件会影响有机物的产生、分配和归宿吗？

• 批准号: 1041038
• 负责人: Uta D Passow
• 金额: $ 97.15万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2016-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1041038&HistoricalAwards=false
• 关键词: Will; CO2; conditions; affect; production

Coastal waters are already experiencing episodic exposure to carbonate conditions that were not expected until the end of the century making understanding the response to these episodic events as important as understanding the long-term mean response. Among the most striking examples are those associated with coastal upwelling along the west coast of the US, where the pH of surface waters may drop to 7.6 and pCO2 can reach 1100 uatm. Upwelling systems are responsible for a significant fraction of global carbon export making them prime targets for investigations on how ocean acidification is already affecting the biological pump today. In this study, researchers at the University of California at Santa Barbara will investigate the potential effects of ocean acidification on the strength of the biological pump under the transient increases in CO2 experienced due to upwelling. Increases in CO2 are expected to alter the path and processing of carbon through marine food webs thereby strengthening the biological pump. Increases in inorganic carbon without proportional increases in nutrients result in carbon over-consumption by phytoplankton. How carbon over-consumption affects the strength of the biological pump will depend on the fate of the extra carbon that is either incorporated into phytoplankton cells forming particulate organic matter (POM), or is excreted as dissolved organic matter (DOM). Results from mesocosm experiments demonstrate that the mechanisms controlling the partitioning of fixed carbon between the particulate and dissolved phases, and the processing of those materials, are obscured when both processes operate simultaneously under natural or semi-natural conditions. Here, POM and DOM production and the heterotrophic processing of these materials will be separated experimentally across a range of CO2 concentrations by conducting basic laboratory culture experiments. In this way the mechanisms whereby elevated CO2 alters the flow of carbon along these paths can be elucidated and better understood for use in mechanistic forecasting models. Broader Impacts- The need to understand the effects of ocean acidification for the future of society is clear. In addition to research education, both formal and informal, will be important for informing the public. Within this project 1-2 graduate students and 2-3 minority students will be recruited as interns from the CAMP program (California Alliance for Minority Participation). Within the 'Ocean to Classrooms' program run by outreach personnel from UCSB's Marine Science Institute an educational unit for K-12 students will be developed. Advice and support is also given to the Education Coordinator of NOAA, Channel Islands National Marine Sanctuary for the development of an education unit on ocean acidification.

沿海水域已经经历了到本世纪末才预料到的碳酸盐条件的周期性暴露，因此了解对这些突发事件的反应与了解长期平均反应一样重要。其中最引人注目的例子是与美国西海岸沿岸上升流有关的海流，那里的地表水PH值可能降至7.6，二氧化碳分压可达1100微瓦特。上升流系统占全球碳出口的很大一部分，这使它们成为研究海洋酸化如何影响今天的生物泵的主要目标。在这项研究中，加州大学圣巴巴拉分校的研究人员将调查在上升流导致二氧化碳瞬时增加的情况下，海洋酸化对生物泵强度的潜在影响。二氧化碳的增加预计将改变通过海洋食物网的碳的路径和处理，从而加强生物泵。无机碳的增加而不是营养物质的比例增加会导致浮游植物过度消耗碳。碳的过度消耗如何影响生物泵的强度，将取决于额外碳的命运，这些碳要么被并入浮游植物细胞，形成颗粒有机物(POM)，要么作为溶解有机物(DOM)排出体外。中游实验的结果表明，当两个过程在自然或半自然条件下同时运行时，控制固定碳在颗粒相和溶解相之间的分配以及这些材料的加工的机制是模糊的。在这里，POM和DOM的生产以及这些材料的异养加工将通过进行基本的实验室培养实验，在一定的二氧化碳浓度范围内进行实验分离。通过这种方式，可以阐明和更好地理解二氧化碳升高改变这些路径上的碳流动的机制，以便在机械预测模型中使用。更广泛的影响--显然有必要了解海洋酸化对社会未来的影响。除了研究教育，正式的和非正式的教育对于告知公众也将是重要的。在该项目中，将招募1-2名研究生和2-3名少数族裔学生作为夏令营方案(加州少数族裔参与联盟)的实习生。在由UCSB海洋科学研究所外展人员开展的“从海洋到教室”项目中，将建立一个面向K-12学生的教育单元。还向海峡群岛国家海洋保护区国家海洋和大气局教育协调员提供咨询和支助，以建立一个关于海洋酸化的教育单位。