Collaborative Research: A New Baseline for Antarctic Blue and Fin Whales

蓝鲸和长须鲸是地球上最大的两种动物，也是南大洋中最大的两种磷虾捕食者。南极水域的商业捕鲸始于20世纪初。到20世纪70年代，鲸鱼的数量从数千只减少到只有几百只。在鲸鱼数量大量减少之前，缺乏关于鲸鱼生物学和生态学的数据，这限制了我们对鲸类动物数量更旺盛时生态系统如何运作的理解。然而，最近在史密森尼国家自然历史博物馆重新发现了1946年至1948年间收获的800头南极蓝鲸和长须鲸的须片档案，这将有助于深入了解历史上的鲸鱼生态。随着鲸须的生长，它包含了循环激素和鲸鱼饮食中的化合物，记录了多年来连续的生物和海洋学信息。这个项目将运用一套现代分子技术来研究这些存档的标本，以了解蓝鲸和长须鲸的觅食和繁殖是如何对气候变化、食物网底部的变化和20世纪40年代早期的捕鲸活动做出反应的。通过与更现代的数据集进行比较，这些调查将填补在了解最大的磷虾捕食者、它们对干扰和环境变化的反应以及商业捕鲸对南极海洋生态系统结构和功能的影响方面的主要空白。该项目将与UNCW的海洋探索项目合作，通过为初中和高中女生制定年度计划来改善stem教育。将通过与史密森学会和国际南极旅游运营商协会的合作开展公众宣传，提供有关南极生态系统的新兴研究，并突出博物馆藏品的当代相关性和科学价值。研究过去的条件和极地生物群的适应是预测未来气候变化情景的基础。本研究将使用的鲸须记录为研究自下而上、自上而下和人为对蓝鲸和长须鲸的影响提供了理想的实验平台。这个具有历史意义的鲸须档案包括气候和温度异常强烈的年份，允许气候变化对捕食者和支持它们的生态系统的影响进行研究。此外，商业捕鲸对鲸鱼压力水平的影响将通过将密集捕鲸的年份与二战期间非捕鲸的年份进行比较来调查，这两个年份都是在时间序列中捕获的。这个项目有三种主要的方法。首先，整体稳定同位素分析将用于研究南极蓝鲸和长须鲸的营养动力学。其次，化合物特异性稳定同位素分析（CSIA-AA）将表征南极食物网基地的生物地球化学特征。最后，对鲸须中激素水平的分析将揭示个体压力水平和生殖状态的差异，并为了解鲸类种群生物学提供信息。该项目将产生一个新的公共数据档案，以促进OPP计划各个组成部分的研究机会，所有这些都不受南极实地工作的后勤限制。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。

Blue and fin whales are the two largest animals on the planet, and the two largest krill predators in the Southern Ocean. Commercial whaling in Antarctic waters started in the early 1900?s, and by the 1970's whale populations were reduced from thousands to only a few hundred individuals. The absence of data about whale biology and ecology prior to these large population reductions has limited our understanding of how the ecosystem functioned when cetacean populations were more robust. However, an archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian's National Museum of Natural History that will shed insight into historic whale ecology. As baleen grows, it incorporates circulating hormones, and compounds from the whale's diet, recording continuous biological and oceanographic information across multiple years. This project will apply a suite of modern molecular techniques to these archived specimens to ask how blue and fin whale foraging and reproduction responded to climate variability, changes at the base of the food web, and whaling activities in the early 1940s. By comparison with more modern datasets, these investigations will fill major gaps in understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem. This project will improve stem education through annual programming for middle and high school girls in partnership with UNCW's Marine Quest program. Public outreach will occur through partnerships with the Smithsonian and the International Association of Antarctic Tour Operators to deliver emerging research on Antarctic ecosystems and highlight the contemporary relevance and scientific value of museum collections. Examination of past conditions and adaptations of polar biota is fundamental to predictions of future climate change scenarios. The baleen record that will be used in this study forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. This historic baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of commercial whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. There are three main approaches to this project. First, bulk stable isotope analysis will be used to examine the trophic dynamics of Antarctic blue and fin whales. Second, compound-specific stable isotope analyses (CSIA-AA) will characterize the biogeochemistry of the base of the Antarctic food web. Finally, analyses of hormone levels in baleen will reveal differences in stress levels and reproductive status of individuals, and inform understanding of cetacean population biology. This project will generate a new public data archive to foster research opportunities across various components of the OPP program, all free from the logistical constraints of Antarctic field work.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.