CAREER: "The Omnivore's Dilemma": The Effect of Autumn Diet on Winter Physiology and Condition of Juvenile Antarctic Krill

南极磷虾对南大洋至关重要，因为它们为大量的海洋哺乳动物、海鸟和鱼类提供了食物，其中一些几乎完全以磷虾为食。南极磷虾也是南大洋工业渔业的目标物种。南极磷虾种群的成功很大程度上取决于它们的后代能否在食物极度匮乏的漫长、黑暗的冬季生存下来。为了度过漫长黑暗的冬天，年轻的南极磷虾在秋天必须有高质量的饮食。然而，南极洲某些地区的变暖正在改变极地食物网的动态和质量，导致年轻磷虾在秋季可获得的食物类型发生变化。目前还不清楚这些动态变化是如何影响磷虾过冬的能力的。该项目旨在填补目前对南极磷虾生命周期中一个未被充分研究的阶段的重要知识空白，即1岁的幼虾。从这项工作中得到的结果将有助于改进生物能量、种群和生态系统模型的发展，并将促进目前对这一关键南极物种的科学认识。这个CAREER项目的核心教育和推广目标是加强STEM领域的教育和增加多样性。将开设一门整合本科研究和写作的本科课程，以促进学生对原始研究数据的真实科学探究和分析，并提高他们的沟通技巧。将开设一门研究生课程，以提高学生向非科学听众传达自己研究成果的技能。研究生将通过拟议的研究得到支持，并将获得宝贵的研究经验。传统上得不到充分服务的本科生将被招募在更大项目的框架下进行独立研究。在每个实地考察季，研究小组将维持一个每周的博客，其中包括突出研究的短视频、照片和文字，以及他们在南极洲生活和工作的经历。这个博客的目的是让公众参与进来，提高对南极生态系统和变暖影响的认识和理解，以及对科学研究和发现过程的认识和理解。在这个为期5年的CAREER项目中，研究者将采用实证和理论相结合的方法来评估秋冬季节饲料对1岁龄磷虾的影响。本研究围绕四个假设展开：（H1）秋季饵料影响1岁龄磷虾入冬时的生理状态；（H2）不同冬季摄食条件下，秋饲对1龄磷虾冬季生理状况的影响；（H3） 1年龄磷虾从秋至冬的生理状况变化率取决于秋季饵料；（H4） 1岁磷虾的冬季能量收支在不同年份之间存在差异，且取决于秋季饲料。长期饲养试验和现场取样将用于测量磷虾的生理和状况变化与它们的饮食和饲养环境的关系。经验导出的数据将用于建立生长率和能量预算的理论模型，以确定饮食如何影响1岁磷虾的越冬存活率。该研究将与一项教育和推广计划相结合，以(1)开发引人入胜的本科和研究生课程，(2)培养和发展从事极地研究的年轻科学家，以及(3)吸引公众并提高他们的认识和理解。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。

Antarctic krill are essential in the Southern Ocean as they support vast numbers of marine mammals, seabirds and fishes, some of which feed almost exclusively on krill. Antarctic krill also constitute a target species for industrial fisheries in the Southern Ocean. The success of Antarctic krill populations is largely determined by the ability of their young to survive the long, dark winter, where food is extremely scarce. To survive the long-dark winter, young Antarctic krill must have a high-quality diet in autumn. However, warming in certain parts of Antarctica is changing the dynamics and quality of the polar food web, resulting in a shift in the type of food available to young krill in autumn. It is not yet clear how these dynamic changes are affecting the ability of krill to survive the winter. This project aims to fill an important gap in current knowledge on an understudied stage of the Antarctic krill life cycle, the 1-year old juveniles. The results derived from this work will contribute to the development of improved bioenergetic, population and ecosystem models, and will advance current scientific understanding of this critical Antarctic species. This CAREER project's core education and outreach objectives seek to enhance education and increase diversity within STEM fields. An undergraduate course will be developed that will integrate undergraduate research and writing in way that promotes authentic scientific inquiry and analysis of original research data by the students, and that enhances their communication skills. A graduate course will be developed that will promote students' skills in communicating their own research to a non-scientific audience. Graduate students will be supported through the proposed study and will gain valuable research experience. Traditionally underserved undergraduate students will be recruited to conduct independent research under the umbrella of the larger project. Throughout each field season, the research team will maintain a weekly blog that will include short videos, photographs and text highlighting the research, as well as their experiences living and working in Antarctica. The aim of the blog will be to engage the public and increase awareness and understanding of Antarctic ecosystems and the impact of warming, and of the scientific process of research and discovery.In this 5-year CAREER project, the investigator will use a combination of empirical and theoretical techniques to assess the effects of diet on 1-year old krill in autumn-winter. The research is centered on four hypotheses: (H1) autumn diet affects 1-year old krill physiology and condition at the onset of winter; (H2) autumn diet has an effect on winter physiology and condition of 1-year old krill under variable winter food conditions; (H3) the rate of change in physiology and condition of 1-year old krill from autumn to winter is dependent on autumn diet; and (H4) the winter energy budget of 1-year old krill will vary between years and will be dependent on autumn diet. Long-term feeding experiments and in situ sampling will be used to measure changes in the physiology and condition of krill in relation to their diet and feeding environment. Empirically-derived data will be used to develop theoretical models of growth rates and energy budgets to determine how diet will influence the overwinter survival of 1-year old krill. The research will be integrated with an education and outreach plan to (1) develop engaging undergraduate and graduate courses, (2) train and develop young scientists for careers in polar research, and (3) engage the public and increase their awareness and understanding.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.