Collaborative Research: Using Multiple Stable Isotopes to Investigate Middle to Late Holocene Ecological Responses by Adelie Penguins in the Ross Sea

南极企鹅（Pygoscelis adeliae）是南极洲数量最多的企鹅，尽管它的数量目前正面临着气候变化、海冰栖息地减少和食物供应的威胁。在罗斯海地区，寒冷干燥的环境使企鹅的骨头、羽毛、蛋壳甚至木乃伊的遗骸得以保存，这些活跃的和废弃的栖息地可以追溯到末次冰期（距今45000多年）之前。4000 - 2000年前的一个变暖时期，被称为企鹅的“最佳时期”，海冰面积减少，使企鹅得以进入罗斯海南部并在那里繁殖。随着海洋环境随着当前的变暖趋势发生变化，这条海岸线可能会在未来被重新占用。该项目将使用保存完好的骨头和其他组织来研究企鹅“最佳”期之前、期间和之后的饮食和觅食行为的生态反应。主要研究人员将收集并分析罗斯海栖息地的骨头、羽毛和蛋壳，以确定千年来种群规模和觅食地点的变化。这些栖息地大多与被海冰包围的开放水域的高产区有关。目前的气候变暖趋势正在引起该物种相对迅速的生态反应，由于海平面上升，罗斯海的一些最大的殖民地可能在未来50年内被遗弃。最近建立的罗斯海海洋保护区旨在保护南极企鹅和它们在该地区的觅食地不受人类的影响，而有关该物种过去如何应对气候变化的知识将有助于实现这一目标。这个项目有利于美国国家科学基金会扩大南极系统、生物群和过程的基础知识的使命。与他们的研究项目相结合，首席研究员将为本科生创造研究驱动课程的机会，将设计K-12课程并评估这些活动的有效性。该项目将支持两名研究生与K-12教师一起更新和完善课程。还包括对1名博士、2名硕士和8名本科生的培训和部分支持。公众将通过社交媒体和YouTube频道制作。一套三种稳定的同位素（碳、氮和硫）将在阿德利企鹅的骨头和羽毛中进行分析，以评估随着时间的推移生态变化。碳和氮的稳定同位素分析（δ13C和δ15N）通常用于研究动物迁徙，觅食地点和饮食，特别是可以长途旅行的海洋物种。硫（δ34S）不常用，但越来越多地用于精炼和确证从碳和氮分析中获得的数据。胶原蛋白是这些分析的最佳组织之一，因为它在骨骼中含量丰富，保存良好，并且可以很容易地提取用于分析。利用胶原蛋白中的这三种同位素，研究人员将对罗斯海南部、中部和北部的古代和现代企鹅群落进行调查，以确定数千年来种群数量和觅食地点的变化。这些栖息地大多与罗斯海的三个冰礁之一有关。这项研究将是同类研究中首次应用多种稳定同位素分析来调查一种海鸟在一个地区存活了几千年的物种。这个项目的结果也将为受气候变化影响的阿德利企鹅保护的最佳实践提供管理信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Adélie penguin (Pygoscelis adeliae) is the most abundant penguin in Antarctica, though its populations are currently facing threats from climate change, loss of sea ice habitat and food supplies. In the Ross Sea region, the cold, dry environment has allowed preservation of Adélie penguin bones, feathers, eggshell and even mummified remains, at active and abandoned colonies that date from before the Last Glacial Maximum (more than 45,000 years ago) to the present. A warming period at 4,000-2,000 years ago, known as the penguin ‘optimum’, reduced sea ice extent and allowed this species to access and reproduce in the southern Ross Sea. This coastline likely will be reoccupied in the future as marine conditions change with current warming trends. This project will investigate ecological responses in diet and foraging behavior of the Adélie penguin using well-preserved bones and other tissues that date from before, during and after the penguin ‘optimum’. The Principal investigators will collect and analyze bones, feathers and eggshells from colonies in the Ross Sea to determine changes in population size and feeding locations over millennia. Most of these colonies are associated with highly productive areas of open water surrounded by sea ice. Current warming trends are causing relatively rapid ecological responses by this species and some of the largest colonies in the Ross Sea are likely to be abandoned in the next 50 years from rising sea level. The recently established Ross Sea Marine Protected Area aims to protect Adélie penguins and their foraging grounds in this region from human impacts and knowledge on how this species has responded to climate change in the past will support this goal. This project benefits NSF’s mission to expand fundamental knowledge of Antarctic systems, biota, and processes. In association with their research program, the Principal Investigators will create undergraduate opportunities for research-driven coursework, will design K-12 curriculum and assess the effectiveness of these activities. Two graduate students will be supported by this project to update and refine the curricula working with K-12 teachers. There is also training and partial support included for one doctorate, two master and eight undergraduate students. General public will be reached through social media and YouTube channel productions.A suite of three stable isotopes (carbon, nitrogen, and sulfur) will be analyzed in Adelie penguin bones and feathers from active and abandoned colonies to assess ecological shifts through time. Stable isotope analyses of carbon and nitrogen (δ13C and δ15N) are commonly used to investigate animal migration, foraging locations and diet, especially in marine species that can travel over great distances. Sulfur (δ34S) is not as commonly used but is increasingly being applied to refine and corroborate data obtained from carbon and nitrogen analyses. Collagen is one of the best tissues for these analyses as it is abundant in bone, preserves well, and can be easily extracted for analysis. Using these three isotopes from collagen, ancient and modern penguin colonies will be investigated in the southern, central and northern Ross Sea to determine changes in populations and foraging locations over millennia. Most of these colonies are associated with one of three polynyas in the Ross Sea. This study will be the first of its kind to apply multiple stable isotope analyses to investigate a living species of seabird over millennia in a region where it still exists today. Results from this project will also inform management on best practices for Adelie penguin conservation affected by climate change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.