Ocean Acidification Category 1: A mechanistic understanding of the impacts of ocean acidification on the early life stages of marine bivalves

智力优势：由于直接人为增加二氧化碳和气候驱动的循环变化，海洋沃茨碳酸盐化学性质发生变化，对许多生物构成威胁。 大量文献表明，碳酸水平的增加和碳酸盐的减少将对许多海洋生物产生有害影响;然而，人们对水化学中这些变化的作用方式知之甚少。 许多海洋生物，特别是双壳类，严重依赖于碳酸钙矿物的生产，这种材料在酸性条件下变得不稳定。 然而，实际的矿物沉淀发生在生物膜间歇性地与周围海水隔开的间隙体积内。 因此，固相矿物和海水热力学之间的非生物关系是海水化学，双壳类生理学和壳生长过程之间复杂相互作用的过于简化的表示。 这个综合性的多学科项目将开发和应用新的实验方法，以阐明与海洋酸化相关的海水化学变化的基本生理反应。 PI将：1）开发一种新的实验方法和系统，能够独特地组合pCO2、pH和矿物饱和状态，2）进行短期探索性实验，以确定双壳类对不同碳酸盐系统变量的反应，3）对双壳类早期生活史中不同碳酸盐系统变量的综合影响进行长期定向研究，（4）比较了一组壳矿物学和原生性不同的双壳类物种对北美太平洋西北海岸周期性酸化上升流区的生物反应。 将对具有本地和非本地物种对的三个主要分类群（牡蛎、贻贝、蛤）进行广泛的实验室实验：牡蛎Ostrea lurida和Crassostrea gigas;贻贝Mytilus califonianus和Mytilus galloprovincialis;蛤Macoma nasuta和菲律宾蛤仔Ruditapes philippinarum。 高精度pCO2和溶解无机碳（DIC）仪器将用于实验，以控制和适当约束碳酸盐化学。 将在这些物种的早期生命阶段测量响应变量的补充，包括组织酸碱平衡，外壳矿物学和化学，呼吸率和行为。 此外，重点将放在观察的发展，增长和壳结构，同时直接连接观测数据与其他测量的响应数据。 短期实验将确定碳酸盐系统中最显着的变量，以便在长期研究中进行操纵。 这种方法还将允许评估急性效应，模拟沿海地区经常发现的碳酸盐变量的日变化，以及模拟大气CO2上升导致的更渐进的酸化的综合慢性效应。 目前，在迄今为止的所有海洋酸化实验中，pCO2，pH值和Omega的混淆效应使得阐明生物体对海洋酸化反应的潜在生理机制变得非常困难。 将这一方法应用于一组具有不同外壳结构和出生时间的相关双壳类动物，以应对周期性酸化的环境，将回答脆弱物种将如何受到海洋酸化影响的基本问题。在实验系统开发完成后，预计将与其他海洋酸化研究小组开展重要的交叉合作，因为仪器和控制电路是紧凑的并且是高度便携的。该项目的主要研究人员已经并将继续与包括水产养殖业、政府官员、学生团体和公众在内的广泛用户群体讨论海洋酸化问题。该项目的主要参与者将开发一个网页，以提供一种既可理解又科学的方式处理海洋酸化问题，特别是沿海海洋和河口的酸化问题。 Waldbusser还与水产养殖倡导团体就编写宣传材料进行了沟通。 此外，将在四年项目期间支助和培训三名研究生。

Intellectual Merit: The shift in the carbonate chemistry of marine waters, as a result of direct anthropogenic CO2 addition and climate-driven changes in circulation, poses a threat to many organisms. A rapidly expanding body of literature has shown that increasing levels of carbonic acid and decreasing carbonate will have deleterious effects on many marine organisms; however little is known about the mode of action of these changes in water chemistry. Many marine organisms, particularly bivalves, depend critically on the production of calcium carbonate mineral, and this material becomes thermodynamically unstable under more acidic conditions. The actual mineral precipitation, however, takes place within interstitial volumes intermittently separated from ambient seawater by biological membranes. Therefore, abiotic relationships between solid phase minerals and seawater thermodynamics are oversimplified representations of the complex interplay among seawater chemistry, bivalve physiology, and shell growth processes. This integrative, multi-disciplinary project will develop and apply novel experimental approaches to elucidate fundamental physiological responses to changes in seawater chemistry associated with ocean acidification. The PIs will: 1) develop a novel experimental approach and system capable of unique combinations of pCO2, pH, and mineral saturation state, 2) conduct short-term exploratory experiments to determine bivalve responses to different carbonate system variables, 3) conduct longer-term directed studies of the integrated effects of different carbonate system variables over early life history of bivalves, and 4) compare these biological responses among a group of bivalve species that differ in shell mineralogy and nativity to the periodically acidified upwelling region of the Pacific Northwest coast of North America. Extensive laboratory experiments will be carried out on three primary taxa (oyster, mussel, clam) having native and non-native species pairs: oysters Ostrea lurida and Crassostrea gigas; mussels Mytilus califonianus and Mytilus galloprovincialis; and clams Macoma nasuta and Ruditapes philippinarum. High precision pCO2 and dissolved inorganic carbon (DIC) instruments will be used in experiments to control and properly constrain the carbonate chemistry. A compliment of response variables will be measured across the early life stages of these species that include tissue acid-base balance, shell mineralogy and chemistry, respiration rate, and behavior. Additionally, an emphasis will be placed on observation of development, growth, and shell structure while directly linking observational data with other measured response data. Short-term experiments will determine the most salient variables in the carbonate system to manipulate in longer-term studies. This approach will also allow the evaluation of acute effects, mimicking diurnal changes to carbonate variables often found in coastal areas, and integrated chronic effects mimicking a more gradual acidification due to the rise in atmospheric CO2.An experimental approach will be developed that will significantly advance understanding of biological responses to ocean acidification. Currently, the confounding effects of pCO2, pH, and Omega in all ocean acidification experiments to date make it extremely difficult to illuminate the underlying physiological mechanisms of organism responses to ocean acidification. Applying this approach across a group of related bivalves with differences in shell structure and nativity to a periodically acidified environment will answer fundamental questions of how vulnerable species will be affected by ocean acidification.Broader Impacts: A significant cross-collaboration can be anticipated with other ocean acidification research groups after the development of the experimental system, as the instrumentation and control circuits are compact and will be highly portable. The principle investigators on this project have and continue to discuss ocean acidification with a broad base of user groups including the aquaculture industry, government officials, student groups, and the general public. The PIs on this project will develop a webpage to provide an approachable yet scientific treatment of ocean acidification, particularly with respect to the coastal oceans and estuaries. Waldbusser has also been corresponding with aquaculture advocacy groups with regard to developing outreach materials. In addition, three graduate students will be supported and trained over the four-year project period.