Planktonic interactions in a changing ocean: Biological responses of Emiliania huxleyi to elevated pCO2 and their effects on microzooplankton

钙化的Haptophyte Emiliania huxleyi似乎对海洋pCO 2浓度的上升非常敏感。E.记录的响应。huxleyi对pCO 2升高的影响包括其钙化率和细胞大小的改变、球结肠畸形、生长率升高、有机碳产量增加、PIC：POC比率降低以及活性气候气体DMS产量升高。这些参数的变化是引起微型浮游动物（海洋中占主导地位的食草动物功能群）食草行为改变的已知机制。研究人员假设，钙化和非钙化Haptophyte Emiliania huxleyi的生理和生物化学的变化，以应对pCO 2升高将沉淀改变微型浮游动物放牧动态。为了验证这一假设，他们将进行受控的实验室实验，其中几种菌株的E。huxleyi在几种CO2浓度下生长。在仔细表征了E. huxleyi菌株升高pCO 2，他们将提供这些菌株作为食物的几个生态重要的微型浮游动物和文件放牧动态。E. huxleyi是研究浮游植物和微型浮游动物对人为CO2上升的反应的理想生物，其在海洋环境中的影响被称为海洋酸化; huxleyi是生态地球化学重要的，是很好的研究，许多菌株是在文化中表现出上述参数的变化，他们很容易喂养的生态重要的微型浮游动物。智力MeritThe影响的变化，微型浮游动物放牧碳循环，特别是碳酸钙出口，DMS生产，营养再生在表面沃茨，和碳转移之间的营养水平是深刻的，因为这种放牧，在很大程度上，它控制着所有这些过程。E. huxleyi是一种模式猎物生物，因为它是地球化学最具影响力的全球浮游植物之一。它形成大规模的季节性水华，对海洋无机和有机碳循环作出重大贡献，是气候活性气体二甲基硫的主要生产者，也是其本身之上和之下营养级有机物质的来源。计划中的对照研究将增加我们对驱动营养水平之间变化模式的机制的了解，从而提供更广泛的工具，以了解海洋酸化实地研究的复杂性，其中相互竞争的变量可能会混淆精确的解释。本科生的参与将主要来自SPMCs长期的两个居民计划：屡获殊荣的海洋科学多元文化倡议：本科生参与（MIMORM）和本科生研究经验（REU）。该计划的使命声明是通过课程和研究增加下一代海洋科学家的多样性。学生参加MIMONUS进行独立的研究项目，目前在国家和国际会议，并进行社区推广。REU计划为我们的研究提供了一个面向全国观众的门户网站;就在去年，SPMC收到了代表90所不同大学的118份REU申请。来自WWU生物学和环境科学系的本科生也将通过项目PI教授的课程参与这项研究。最后，SPMC已收到资金，聘请K-12外联协调员谁将开发一系列的研讨会，公开讲座和演讲，并贡献K-12课程。这项研究的结果将纳入所有这些外联工作。

The calcifying Haptophyte Emiliania huxleyi appears to be acutely sensitive to the rising concentration of ocean pCO2. Documented responses by E. huxleyi to elevated pCO2 include modifications to their calcification rate and cell size, malformation of coccoliths, elevated growth rates, increased organic carbon production, lowering of PIC:POC ratios, and elevated production of the active climate gas DMS. Changes in these parameters are mechanisms known to elicit alterations in grazing behavior by microzooplankton, the oceans dominant grazer functional group. The investigators hypothesize that modifications to the physiology and biochemistry of calcifying and non-calcifying Haptophyte Emiliania huxleyi in response to elevated pCO2 will precipitate alterations in microzooplankton grazing dynamics. To test this hypothesis, they will conduct controlled laboratory experiments where several strains of E. huxleyi are grown at several CO2 concentrations. After careful characterization of the biochemical and physiological responses of the E. huxleyi strains to elevated pCO2, they will provide these strains as food to several ecologically-important microzooplankton and document grazing dynamics. E. huxleyi is an ideal organism for the study of phytoplankton and microzooplankton responses to rising anthropogenic CO2, the effects of which in the marine environment are called ocean acidification; E. huxleyi is biogeochemically important, is well studied, numerous strains are in culture that exhibit variation in the parameters described above, and they are readily fed upon by ecologically important microzooplankton.Intellectual MeritThe implications of changes in microzooplankton grazing for carbon cycling, specifically CaCO3 export, DMS production, nutrient regeneration in surface waters, and carbon transfer between trophic levels are profound, as this grazing, to a large degree, regulates all these processes. E. huxleyi is a model prey organism because it is one of the most biogeochemically influential global phytoplankton. It forms massive seasonal blooms, contributes significantly to marine inorganic and organic carbon cycles, is a large producer of the climatically active gas DMS, and is a source of organic matter for trophic levels both above and below itself. The planned controlled study will increase our knowledge of the mechanisms that drive patterns of change between trophic levels, thus providing a wider array of tools necessary to understand the complex nature of ocean acidification field studies, where competing variables can confound precise interpretation.Broader ImpactsThis research project will provide support for two early-career scientists, a graduate student, and numerous undergraduate students. Undergraduate student involvement will come largely from SPMCs long-standing two resident programs: the award-winning Multicultural Initiative in the Marine Sciences: Undergraduate Participation (MIMSUP) and Research Experience for Undergraduates (REU). The mission statement of the MIMSUP program is to increase diversity within the next generation of marine scientists through coursework and research. Students participating in MIMSUP conduct independent research projects, present at national and international meetings, and conduct community outreach. The REU program provides the portal for our research to reach a nation-wide audience;just last year SPMC received 118 REU applications representing 90 different universities. Undergraduates from WWUs Biology and Environmental Science departments will also participate in this research through courses taught by the project PIs. Finally, SPMC has received funding to hire a K-12 outreach coordinator who will develop a series of workshops, public lectures and presentations, and contributions to K-12 curriculum. Findings from this research will be incorporated into all of these outreach efforts.