Ocean Acidification: Seasonal and Ontogenetic Effects of Ocean Acidication on Pteropods in the Gulf of Maine

过量的人为CO2溶解到海洋中导致海洋环境pH值下降。这种“海洋酸化”预计将威胁到各种海洋生物，特别是钙化动物，如尾壳（即，带壳的）翼足类动物。这些远洋腹足类形成文石壳，是一些商业上重要的鱼类的猎物，是碳地球化学的重要贡献者。其生态系统的重要性，丰富性和溶解的敏感性使其成为调查酸化影响的重要群体。然而，我们对高CO2对翼足类动物和远洋生态系统的影响的理解主要限于极地生态系统中成年钙化和呼吸反应的短期研究。目前还没有季节性的敏感性研究和我们的理解的影响，二氧化碳对翼足类动物的早期生命阶段是有限的。Limacina retroversa是北大西洋特别丰富的一种带体翼足类动物，在那里它是许多渔业物种和其他顶级捕食者的猎物。该物种也是缅因州（GoM）海湾最常见的翼足类动物，全年都有。L.因此，鉴于其生态重要性及其在容易进入的沃茨中的丰富性，retroversa提供了一个有用的模式翼足类物种的前景。调查人员将进行一系列的短途航行，对L.从墨西哥湾靠近科德角的当地沃茨季节性地反向排放。墨西哥湾的碳酸盐化学随季节波动，为他们提供了评估野生捕获的翼足类动物对二氧化碳自然变化的反应的机会。通过表征水柱的碳酸盐化学，并测量全年翼足类动物的代谢率、外壳质量和基因表达，研究人员将获得翼足类动物对CO2敏感性的时间序列。随后，使用实验操作，研究人员将探讨季节性驯化对翼足类动物对短期和中期暴露于增强的CO2的反应的影响。翼足类动物经常在人工饲养中产卵，WHOI有专门的机构在实验室中维持这些个体。在这些优势的基础上，研究人员还将研究二氧化碳对L.反转海洋钙化物的这些最早的生命阶段被认为是特别敏感的，因为最初的壳沉淀和高能量的生长和发育过程受到CO2暴露的阻碍。他们还将记录死亡率，壳生产，异常，和翼足类胚胎离合器暴露于增加CO2的发育率。智力优点：Thecosome翼足类动物是一个丰富的组钙化动物，一直长期研究不足，特别是在温带地区。由于其可达性和生态重要性，L。retroversa可以被开发为有价值的模型，作为在商业上重要的墨西哥湾地区的优势翼足类动物和在北大西洋的温带沃茨的丰富翼足类动物都是令人感兴趣的。本研究的目的是增加我们对L分布的了解。逆，以了解其对CO2自然变化的季节敏感性，并了解这种暴露如何影响对短期和中期CO2暴露的反应。利用强大的转录组学技术，这项研究将通过调查L。相反，季节性和不同的持续时间和酸化强度，由生态系统和生物体水平的指标。此外，该研究还将首次研究二氧化碳对翼足类动物卵的影响，深入了解它们对酸化环境的敏感性。更广泛的影响：海洋酸化日益被视为一个紧迫的社会问题。这些小体在海洋地球化学循环中非常重要，并且是各种商业鱼类的主要猎物，因此，我们对翼足类动物生态学的更好理解将对我们理解海洋酸化对海洋资源的影响具有重要意义。该项目将以多种方式将研究与教育相结合，包括本科生的培训以及作为博士后（和共同PI）博士职业发展的开创性经验。此外，利用这些迷人的微型动物的美学吸引力，研究人员将与记者，艺术家和摄影师合作，继续开发旨在提高公众对海洋酸化影响的认识的图像和展览。

Dissolution of excess anthropogenic CO2 into the ocean is causing the marine environment to decrease in pH. This "ocean acidification" is predicted to threaten a broad variety of marine organisms, particularly calcifying animals such as the thecosome (i.e., shelled) pteropods. These pelagic gastropods form an aragonite shell, are prey for a number of commercially important fish, and are significant contributors to carbon biogeochemistry. Their ecosystem importance, abundance, and sensitivity to dissolution position them as an important group for investigating the impacts of acidification. Our understanding of the effect of high CO2 on pteropods and the pelagic ecosystem, however, is limited primarily to short-term studies of adult calcification and respiration response in the polar ecosystems. There have been no seasonal studies of sensitivity and our understanding of the effect of CO2 on pteropod early life stages is limited. Limacina retroversa is a particularly abundant thecosome pteropod in the North Atlantic, where it is prey for a number of fisheries species and other top predators. This species is also the most common pteropod in the Gulf of Maine (GoM) where it is present year round. L. retroversa thus offers the prospect of a useful model pteropod species, given both its ecological importance and its abundance in readily accessible waters. The investigators will conduct a series of short cruises to sample L. retroversa on a seasonal basis from local waters of the GoM near Cape Cod. The carbonate chemistry of the GoM fluctuates seasonally, proving them with the opportunity to assess the response of wild caught pteropods to natural changes in CO2. By characterizing the carbonate chemistry of the water column and measuring the metabolic rate, shell quality, and gene expression of pteropods throughout the year, the researchers will achieve a time series of pteropod sensitivity to CO2. Subsequently, using experimental manipulations the investigators will explore the effect of seasonal acclimation on pteropod response to short- and medium-term exposure to enhanced CO2. Pteropods frequently lay eggs in captivity, and at WHOI there is institutional expertise in maintaining these individuals in the laboratory. Building on these strengths, the researchers will also study the effect of CO2 on embryonic and larval development in L. retroversa. These earliest life-stages of marine calcifiers are thought to be especially sensitive since initial shell precipitation and the highly energetic processes of growth and development are impeded by CO2 exposure. They will also document mortality, shell production, abnormality, and developmental rate of clutches of pteropod embryos exposed to increased CO2.Intellectual Merit: Thecosome pteropods are an abundant group of calcifying zooplankters that have been chronically understudied, particularly in temperate regions. Due to its accessibility and ecological importance, L. retroversa can be developed as a valuable model, interesting both as the dominant pteropod in the commercially-important GoM region and also an abundant pteropod in the temperate waters of the North Atlantic. The goal of this research is to augment our knowledge of the distribution of L. retroversa, to attain an understanding of their seasonal sensitivity to natural variability in CO2, and to see how this exposure impacts responses to both short- and medium-term CO2 exposure. Using powerful transcriptomic technologies, the research will transform our understanding of this group by investigating the molecular mechanisms of response in L. retroversa to both seasonality and varying durations and intensities of acidification, contextualized by ecosystem- and organism-level metrics. Furthermore the study will examine the effect of CO2 on the eggs of pteropods for the first time, providing insight into their sensitivity to an acidifying environment.Broader Impacts: Ocean acidification is increasingly appreciated as an urgent societal concern. Thecosomes are important in biogeochemical cycles and as key prey for a variety of commercial fish and as such, the improved understanding we seek of pteropod ecology will have important implications for our understanding of the effects of ocean acidification on marine resources. The project will integrate research with education in a number of ways, including the training of undergraduate students as well as serving as a seminal experience in the career development of postdoc (and co-PI) Dr. Maas. Furthermore, taking advantage of the aesthetic appeal of these charismatic microfauna, the researchers will pair with journalists, artists, and photographers to continue to develop images and exhibitions aimed at increasing public awareness of the impacts of ocean acidification.