Horizontal and Vertical Distribution of Thecosome Pteropods in Relation to Carbonate Chemistry in the Northwest Atlantic and Northeast Pacific

海洋酸化对海洋生态系统的影响是海洋科学家和海洋资源管理者面临的一个重要问题。翼足类是广泛分布于世界各大洋沿岸和开阔洋远洋生态系统中的一类钙质浮游软体动物。这些动物分泌一种文石壳，因此对海洋酸化高度敏感，这是由于水柱的碳酸盐化学变化，特别是文石补偿深度变浅，海水对文石产生腐蚀性。然而，在许多地区，人们对翼足类的丰度、分布、垂直迁移行为和生态重要性知之甚少。评估海洋酸化导致的翼足类动力学变化可能对生态系统造成的后果，需要详细了解翼足类的分布和丰度与水体中文石饱和度变化的关系。本项目的主要目标是量化西北大西洋和东北太平洋的海洋翼足类的分布、丰度、物种组成、外壳条件和垂直迁移行为。并将这些量与水文地理学和碳酸盐化学的同时测量相关联，包括文石饱和度的垂直和水平分布。特别是，该项目将利用当今的变化，在深度分布的文石饱和度水平之间的大西洋和太平洋作为一个“自然实验”，以解决的假设，翼足类垂直分布，物种组成和丰度变化的补偿深度变浅。第二个目标是为翼足类动物丰度的远程量化制定声学协议，以便将来纳入海洋酸化监测网络，并描述两个海洋环流实验/气候变化和应急响应重复水文剖面（大西洋A20和太平洋P17 N）沿着部分碳酸盐化学和营养物的特征，以确定碳酸盐系统的十年尺度变化。这些假设和目标将通过沿西北大西洋和东北太平洋北纬35度至50度之间沿着的两个调查样带进行的两次航行加以解决，其中包括台站工作和正在进行的测量，以及一系列综合仪器，包括声学、光学、网络、水文和碳酸盐化学传感器。这是一个高度跨学科的项目，结合浮游动物生态学，声学和海洋化学的专业知识。这种合作以及同时在现场部署新的生物和化学传感器是研究海洋酸化及其影响的关键下一步，因为以前对海洋酸化的生物影响进行的观测研究很少。拟议的工作将导致详细的基线了解的水平和垂直分布的变化，以及物种组成，thecosome翼足类动物在西北大西洋和东北太平洋，使浮游动物生态学的关键贡献。此外，通过量化对大西洋和太平洋内部和之间当前空间变异的反应，该项目将提供关于翼足类动物分布对文石饱和度垂直分布未来变化的可能反应的重要信息，文石饱和度是模拟海洋酸化对海洋生态系统功能、服务和资源影响的必要组成部分。海洋酸化日益被视为一个紧迫的社会问题。Thecosome pteropods是关键的猎物，各种商业开发的鱼类，和更好的理解的PI寻求的pteropods分布和可能的响应不断变化的水柱碳酸盐化学将有重要的影响，我们的理解海洋酸化对海洋资源的潜在影响。该项目还将以多种方式将研究与教育结合起来，包括对本科生和研究生进行跨学科培训，并将数据和调查结果纳入课程教学。将通过各种门户网站传播对这项工作、其调查结果和对生态/养护的影响的说明，使之成为海洋酸化对生态影响的典型代表。

The impact of ocean acidification on marine ecosystems represents a vital question facing both marine scientists and managers of ocean resources. Thecosome pteropods are a group of calcareous planktonic molluscs widely distributed in coastal and open ocean pelagic ecosystems of the world¡¦s oceans. These animals secrete an aragonite shell, and thus are highly sensitive to ocean acidification due to the water column's changing carbonate chemistry, and particularly the shoaling of the aragonite compensation depth at which seawater becomes corrosive to aragonite. In many regions, however, relatively little is known about the abundance, distribution, vertical migratory behavior, and ecological importance of pteropods. Assessing the likely ecosystem consequences of changes in pteropod dynamics resulting from ocean acidification will require a detailed understanding of pteropod distribution and abundance relative to changing aragonite saturation in the water column.The primary objective of this project is to quantify the distribution, abundance, species composition, shell condition, and vertical migratory behavior of oceanic thecosome pteropods in the northwest Atlantic and northeast Pacific, and correlate these quantities to hydrography and concurrent measurements of carbonate chemistry, including vertical and horizontal distributions of aragonite saturation. In particular, the project will capitalize on present-day variability in the depth distribution of aragonite saturation levels within and between the Atlantic and Pacific Oceans as a "natural experiment" to address the hypotheses that pteropod vertical distribution, species composition, and abundance vary as the compensation depth becomes shallower. Secondary objectives are to develop acoustic protocols for the remote quantification of pteropod abundance for future integration into ocean acidification monitoring networks, and to characterize carbonate chemistry and nutrients along portions of two WOCE/CLIVAR Repeat Hydrography transects (A20 in the Atlantic and P17N in the Pacific) to identify decadal-scale changes in the carbonate system. These hypotheses and objectives will be addressed through two cruises along survey transects between 35 and 50 degrees N in the northwest Atlantic and northeast Pacific involving a combination of station-work and underway measurements, and a comprehensive array of instruments, including acoustic, optical, net, hydrographic, and carbonate chemistry sensors.Intellectual Merit: This is a highly inter-disciplinary project, combining expertise in zooplankton ecology, acoustics, and marine chemistry. Such collaboration and the concurrent in situ deployment of newly-available biological and chemical sensors represent critical next steps in the study of ocean acidification and its impacts, since previous observational studies of the biological impact of ocean acidification have been few. The proposed work will result in a detailed baseline understanding of variability in the horizontal and vertical distribution, as well as species composition, of thecosome pteropods in the northwest Atlantic and northeast Pacific, making a key contribution to zooplankton ecology generally. In addition, by quantifying the response to current spatial variability within and between the Atlantic and Pacific Oceans, the project will provide important information on the likely response of pteropod distribution to future changes in the vertical distribution of aragonite saturation levels, a necessary component in modeling the impacts of ocean acidification on marine ecosystem function, services, and resources.Broader Impacts: Ocean acidification is increasingly appreciated as an urgent societal concern. Thecosome pteropods are key prey for a variety of commercially-exploited fish species, and the improved understanding the PIs seek of pteropod distribution and likely response to changing water column carbonate chemistry will have important implications for our understanding of potential effects of ocean acidification on marine resources. The project will also integrate research with education in a number of ways, including the inter-disciplinary training of undergraduate and graduate students and incorporation of the data and findings into course-based teaching. Descriptions of the work, its findings, and ecological/conservation implications intelligible to a lay audience will be disseminated via a combination of web portals, advancing "pelagic snails" as a poster child of the planktonic impacts of ocean acidification.