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

南极磷虾在南大洋是必不可少的，因为它们养活了大量的海洋哺乳动物、海鸟和鱼类，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在很大程度上取决于它们的后代能否在漫长而黑暗的冬季生存下来，那里的食物极其稀缺。为了度过漫长而黑暗的冬天，南极磷虾幼体必须在秋季有高质量的食物。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，导致秋季幼虾可获得的食物类型发生变化。目前尚不清楚这些动态变化如何影响磷虾越冬的能力。该项目旨在填补目前关于南极磷虾生命周期中一个未被充分研究的阶段--1岁幼虾--知识的一个重要空白。这项工作的结果将有助于开发改进的生物能量学、种群和生态系统模型，并将促进目前对这一关键南极物种的科学理解。这一职业项目的核心教育和外展目标旨在加强教育，增加STEM领域的多样性。将开发一门本科课程，将本科生的研究和写作结合起来，促进学生对原始研究数据进行真实的科学探究和分析，并提高他们的沟通能力。将开发一门研究生课程，促进学生向非科学受众交流他们自己的研究的技能。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。传统上服务不足的本科生将被招募到这个更大的项目的保护伞下进行独立研究。在整个考察季节，研究团队将保持每周一次的博客，其中将包括短视频、照片和文字，重点介绍研究以及他们在南极洲生活和工作的经历。该博客的目的将是让公众参与进来，提高对南极生态系统、变暖的影响以及研究和发现的科学过程的认识和理解。在这个为期5年的职业项目中，研究人员将使用经验和理论技术相结合的方法来评估秋冬季饮食对一岁磷虾的影响。这项研究围绕四个假设展开：(H1)秋季饮食影响一岁磷虾在入冬时的生理和状况；(H2)秋季饮食对一岁磷虾在不同冬季食物条件下的冬季生理和状况有影响；(H3)一岁磷虾从秋季到冬季的生理和状况变化速度取决于秋季饮食；以及(H4)一岁磷虾的冬季能量收支将在不同年份之间变化，并将取决于秋季饮食。长期饲养实验和现场采样将被用来测量磷虾的生理和条件的变化，与它们的饮食和摄食环境有关。来自经验的数据将被用来开发生长率和能量预算的理论模型，以确定饮食将如何影响一岁磷虾的越冬存活。这项研究将与教育和推广计划相结合，以(1)开发吸引人的本科生和研究生课程，(2)培养和发展从事极地研究职业的年轻科学家，以及(3)吸引公众并提高他们的意识和理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力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.