Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators

南极海洋生态系统的生产力很高，支持各种具有生态和商业重要性的物种。 这个生态系统中的一个关键物种是南极磷虾，除了被商业捕捞外，它还是包括企鹅、海豹和鲸鱼在内的各种海洋生物的主要猎物。 这项研究的目的是利用企鹅和其他磷虾捕食者作为敏感指标，反映气候变化和人类历史上对海豹和鲸鱼的捕捞造成的南极海洋食物网过去的变化。具体来说，这项研究将恢复和分析现代（20岁），历史（20-200岁）和古代（200- 10，000岁）企鹅和其他磷虾捕食者组织，以跟踪他们过去的饮食和人口移动相对于气候变化和南极磷虾的可用性。了解磷虾捕食者过去如何受到这些因素的影响，将使我们更好地了解这些捕食者，它们所依赖的磷虾以及整个南极海洋生态系统将如何应对当前的挑战，例如全球气候变化和南极磷虾商业渔业的扩大。 该项目将进一步推动NSF培养新一代科学家和向公众提供科学发现的目标。该项目将支持对本科生和研究生进行生态学和地球化学领域高级分析技术的跨机构培训。 此外，该项目还包括旨在鼓励参与科学事业的教育推广活动，让K-12学生参与与南极洲、企鹅、海洋生态、海洋地球化学、和全球气候变化。这项研究将有助于通过检查十年和千年来将南大洋最近的生态变化置于更大的历史背景中-南极磷虾捕食者（企鹅、海豹和鱿鱼）的饮食和种群移动的规模变化与气候变化和商业捕捞相一致。 这将通过耦合先进的稳定和放射性同位素技术，特别是化合物特定的稳定同位素分析，与前所未有的访问现代，历史和保存完好的古档案南极捕食者组织约会整个全新世。 这种方法将使该项目能够凭经验测试，如果观察到的变化在南极捕食者散装组织稳定同位素值在过去的千年是由气候驱动的变化在食物网的基础上，除了，而不是，捕食者饮食的变化，由于竞争性释放后，历史性的收获磷虾吃鲸鱼和海豹。此外，该项目还将跟踪南极洲周围企鹅群因过去几千年来气候和海冰状况的变化而被大规模遗弃和重新占据的情况。这些综合的实地研究和实验室分析将为影响企鹅等魅力磷虾捕食者过去饮食和人口流动变化的潜在机制提供新的见解。这将有助于更好地预测未来气候变化对生态系统的影响以及南极洲可能影响南极磷虾供应的人为捕捞情景。

The Antarctic marine ecosystem is highly productive and supports a diverse range of ecologically and commercially important species. A key species in this ecosystem is Antarctic krill, which in addition to being commercially harvested, is the principle prey of a wide range of marine organisms including penguins, seals and whales. The aim of this study is to use penguins and other krill predators as sensitive indicators of past changes in the Antarctic marine food web resulting from climate variability and the historic harvesting of seals and whales by humans. Specifically this study will recover and analyze modern (20 year old), historic (20-200 year old) and ancient (200-10,000 year old) penguin and other krill predator tissues to track their past diets and population movements relative to shifts in climate and the availability of Antarctic krill. Understanding how krill predators were affected by these factors in the past will allow us to better understand how these predators, the krill they depend on, and the Antarctic marine ecosystem as a whole will respond to current challenges such as global climate change and an expanding commercial fishery for Antarctic krill. The project will further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This project will support the cross-institutional training of undergraduate and graduate students in advanced analytical techniques in the fields of ecology and biogeochemistry. In addition, this project includes educational outreach aimed encouraging participation in science careers by engaging K-12 students in scientific issues related to Antarctica, penguins, marine ecology, biogeochemistry, and global climate change.This research will help place recent ecological changes in the Southern Ocean into a larger historical context by examining decadal and millennial-scale shifts in the diets and population movements of Antarctic krill predators (penguins, seals, and squid) in concert with climate variability and commercial harvesting. This will be achieved by coupling advanced stable and radio isotope techniques, particularly compound-specific stable isotope analysis, with unprecedented access to modern, historical, and well-preserved paleo-archives of Antarctic predator tissues dating throughout the Holocene. This approach will allow the project to empirically test if observed shifts in Antarctic predator bulk tissue stable isotope values over the past millennia were caused by climate-driven shifts at the base of the food web in addition to, or rather than, shifts in predator diets due to a competitive release following the historic harvesting of krill eating whale and seals. In addition, this project will track the large-scale abandonment and reoccupation of penguin colonies around Antarctica in response to changes in climate and sea ice conditions over the past several millennia. These integrated field studies and laboratory analyses will provide new insights into the underlying mechanisms that influenced past shifts in the diets and population movements of charismatic krill predators such as penguins. This will allow for improved projections of the ecosystem consequences of future climate change and anthropogenic harvesting scenarios in the Antarctica that are likely to affect the availability of Antarctic krill.