Drivers of Antarctic Krill Reproductive Output

南极半岛北部的变暖正在引起海洋生态系统的根本变化。南极磷虾是一种类似虾的小动物，在该地区数量最多。它们也是南极洲周围水域海洋食物网的重要组成部分。与此同时，磷虾的国际渔业发展迅速。因此，了解磷虾种群的变化对渔业管理和科学家预测南极海洋生态系统变化的能力都至关重要。该项目将产生两大社会影响。首先，该项目将支持培养从事海洋学工作的学生。这些学生将从代表性不足的群体中招募，以增加STEM的多样性、公平性和包容性。第二，该项目的结果将发展改进的种群模型，这对有效管理南极磷虾渔业至关重要。研究人员将与南极海洋生物资源保护委员会的美国代表合作，编写一份报告，概述这项研究的主要发现。有效的种群建模依赖于对环境如何驱动磷虾繁殖的经验和理论理解。南极磷虾有两个关键的卵发育阶段影响种群的增长。它们是早期卵发育和晚期卵发育/产卵。早期卵发育的时间和持续时间决定了产卵的数量和雌性可以经历的季节性产卵事件的数量。研究小组将使用过去30年来在冬末/早春、夏季和初秋收集的南极磷虾样本。将对这些样本中单个雌性的生殖发育阶段进行评估。这些数据将根据气候学和海洋学数据进行建模，以检验三个假设。首先，它们将测试较冷的冬季条件是否适合提前为产卵做准备。其次，他们将测试有利的冬夏条件是否会增加早期产卵。最后，它们将测试有利的冬夏条件是否会延长产卵期。该研究将促进目前对促进南极磷虾种群增长的环境条件的认识，并将填补目前对南极磷虾生殖发育和产量的认识的重要空白。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。

Warming at the northern Antarctic Peninsula is causing fundamental changes in the marine ecosystem. Antarctic krill are small shrimp-like animals that are most abundant in that area. They are also an essential part of the marine food web of the waters surrounding Antarctica. Meanwhile, a rapidly growing international fishery has developed for krill. Understanding changes in krill populations is therefore critical both to the management of the fishery and the ability of scientists to predict changes in the Antarctic marine ecosystem. This project will have two broader societal impacts. First, the project will support the training of students for careers in oceanography. The students will be recruited from underrepresented groups in an effort to increase diversity, equity and inclusion in STEM. Second, results from this project will develop improved population models, which are essential for the effective management of the Antarctic krill fishery. In collaboration with US delegates on the Commission for the Conservation of Antarctic Marine Living Resources, the researchers will produce a report outlining the key findings from the study.Effective population modeling relies on empirical and theoretical understanding of how environment drives krill reproduction. There are two critical egg development stages in Antarctic krill that impact population growth. They are early egg development, and advanced egg development/spawning. The timing and duration of early egg development determines the number of eggs produced and the number of seasonal spawning events a female can undergo. The research team will use samples of Antarctic krill collected over the last 30 years in late winter/early spring, summer and early fall. The reproductive development stages of individual females in these samples will be assessed. These data will be modeled against climatological and oceanographic data to test three hypotheses. First, they will test if colder winter conditions correspond to early preparation for spawning. Second, they will test if favorable winter-summer conditions increase early spawning. Finally, they will test if favorable winter-summer conditions lengthen the spawning season. The study will advance current understanding of the environmental conditions that promote population increases in Antarctic krill and will fill an important gap in current knowledge of the reproductive development and output of Antarctic krill.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.