Ocean Acidification - Effects of ocean acidification on Emiliania huxleyi and Calanus finmarchicus; insights into the oceanic alkalinity and biological carbon pumps

海洋酸化是我们这个时代最紧迫的海洋科学问题之一，潜在的生物影响横跨所有海洋门，潜在的社会影响影响人类与海洋的关系。大气中二氧化碳水平的上升正在增加世界海洋的酸度。一般认为，相对于工业化前的水平，表层海洋的平均pH值已经下降了0.1个pH值单位(Orr等人，2005年)，预计到本世纪末将下降0.3至0.46个单位，这取决于二氧化碳排放情景(Caldeira和Wickett，2005年)。这项研究的总体目标是对二氧化碳水平的变化如何改变世界海洋的生物和碱度泵进行参数化。具体而言，海洋酸化的直接和间接影响将在一个简单的、受控的捕食者/猎物系统中进行研究，该系统包含一个被捕食的浮游植物物种(球石浮游动物Emily huxleyi)和一个捕食者(海洋后生动物食草动物Calanus finmarchicus)。这些实验旨在阐明直接影响(即海洋酸化仅对单个生物体的影响)和交互影响(即对捕食者/猎物组合系统的影响)。与浮游植物猎物和浮游动物捕食者的互动实验是预测海洋酸化对海洋生态系统的整体影响的关键起点。为了实现这些目标，将建造一个最先进的设施，配备经过校准的生长室，并具有高度可控的pH值和碱度水平。这种方法的优势在于将进行细致的校准和多余的测量，以确保室内条件得到很好的描述，并对DIC水平进行严密监测。将测量球石生物的生长和钙化速度以及对桡足类动物的发育速度、形态和行为的影响。将监测藻类和排泄物颗粒中的PIC和POC的变化，以了解PIC/POC比率的变化，这是模拟二氧化碳水平上升反馈机制的关键参数。此外，还计划进行14C实验，以测量球石生物体的钙化率和放牧造成的溶解速度。这些关键的实验将验证PIC在质量平衡中的闭合，从而能够确定PIC在桡足类谷物肠道内的实际溶解速度。参与这项工作的科学家团队贡献了在尺足类生态学、生物地理学和生理学(Balch)和桡足类生态和生理学(Fields)方面的专业知识。他们将与一名博士后研究员和一名能力很强的技术人员一起提供必要的支持，以培养和监测实验期间的文化。六名受指导的本科生将有与这项工作相关的项目。碳酸盐化学方面的专业知识将由N·贝茨博士提供(顾问，见支持函)。除了海洋酸化对科学和社会产生了许多更广泛的影响外，这项工作还产生了重大的教育影响。这个项目有许多独立的子项目，将为有动力的本科生提供特殊的机会，让他们获得实践研究经验，学习复杂的培养技术，光学和显微摄像的基础知识。六名受指导的本科生将有与这项工作相关的项目。学生将被要求每周见面，并就他们各自的项目举行一次比奇罗研讨会。将鼓励和支持参加国家会议。鲍尔奇和菲尔兹过去在本科生中取得了巨大的成功，有几个人在收录了他们的工作的出版物上获得了作者资格。他们还将邀请几名高中生进入实验室，协助该项目的基本方面。菲尔兹参与了COSEE项目(旨在将海洋科学带到农村地区)和“Keller Bloom”项目，该项目为来自缅因州农村的天才高中生提供为期一周的科学沉浸式课程。该项目的成果还将有助于其他BLOS教育和外展计划的发展，最著名的是每周一次的夏季研讨会系列向公众开放，夏季REU计划和毕格罗实验室新的科尔比大学学期计划。这项提案的资金将用于建设一个最先进的设施，用于创建、维护和监测二氧化碳浓度。

Ocean acidification is one of the most pressing marine science issues of our time, with potential biological impacts spanning all marine phyla and potential societal impacts affecting man's relationship to the sea. Rising levels of atmospheric pCO2 are increasing the acidity of the world oceans. It is generally held that average surface ocean pH has already declined by 0.1 pH units relative to the pre-industrial level (Orr et al., 2005), and is projected to decrease 0.3 to 0.46 units by the end of this century, depending on CO2 emission scenarios (Caldeira and Wickett, 2005). The overall goal of this research is to parameterize how changes in pCO2 levels could alter the biological and alkalinity pumps of the world ocean. Specifically, the direct and indirect effects of ocean acidification will be examined within a simple, controlled predator/prey system containing a single prey phytoplankton species (the coccolithophore, Emiliania huxleyi) and a single predator (the oceanic metazoan grazer, Calanus finmarchicus). The experiments are designed to elucidate both direct effects (i.e. effects of ocean acidification on the individual organisms only) and interactive effects (i.e. effects on the combined predator/prey system). Interactive experiments with phytoplankton prey and zooplankton predator are a critical starting point for predicting the overall impact of ocean acidification in marine ecosystems. To meet these goals, a state-of-the-art facility will be constructed with growth chambers that are calibrated and have highly-controlled pH and alkalinity levels. The strength of this approach lies in meticulous calibration and redundant measurements that will be made to ensure that conditions within the chambers are well described and tightly monitored for DIC levels. Growth and calcification rates in coccolithophores and the developmental rates, morphological and behavioral effects on copepods will be measured. The PIC and POC in the algae and the excreted fecal pellets will be monitored for changes in the PIC/POC ratio, a key parameter for modeling feedback mechanisms for rising pCO2 levels. In addition, 14C experiments are planned to measure calcification rates in coccolithophores and dissolution rates as a result of grazing. These key experiments will verify closure in the mass balance of PIC, allowing the determination of actualdissolution rates of PIC within the guts of copepod grazers.The team of scientists in this work contributes expertise in coccolithophore ecology, biogeography and physiology (Balch) and copepod ecology and physiology (Fields). They will be joined by a post-doctoral fellow and a highly capable technical staff to provide the necessary support to cultivate and monitor cultures during experiments. Six supervised undergraduate students will have projects associated with this work. Expertise in carbonate chemistry will be provided by Dr. N. Bates (consultant, see letter of support).Broader Impact. Along with the numerous scientific and societal broader impacts of ocean acidification, there are also significant educational impacts associated with this work. This project has numerous self-contained sub-projects that will provide exceptional opportunities for motivated undergraduate students to receive hands-on research experience, learning sophisticated culturing techniques, the fundamentals of optics and micro-videography. Six supervised undergraduate students will have projects associated with this work. Students will be required to meet weekly and to give a Bigelow seminar on their respective projects. Participation at national meetings will be encouraged and supported. Balch and Fields have had great success with undergraduate students in the past with several receiving authorship on publications that incorporated their work. They will also invite several high school students into the lab to assist with basic aspects of the project. Fields is involved in the COSEE program (designed to bring ocean science to rural areas) and the "Keller Bloom" project, which provides a week-long science immersion course to gifted high school students from rural Maine. Results of the project will also contribute to the development of other BLOS educational and outreach programs, most notably weekly summer seminar series open to the public, the summer REU program and a new Colby College semester program at Bigelow Laboratory. Funds from this proposal will be used to build a state-of- the-art facility for creating, maintaining and monitoring pCO2 concentrations.