Collaborative Research: Modeling organismal responses to changing ecological regimes via investigation of stress, growth and reproduction in the longest-lived mammal

这个项目使用新技术来分析历史博物馆的鲸须标本（从鲸鱼上颚缓慢生长的角蛋白长条），以研究环境变化如何影响长寿动物。环境变化会对野生动物产生巨大影响，但这些影响往往需要多年才能缓慢显现，这对科学家在足够长的时间内收集数据的能力提出了挑战。最近发现，鲸须中含有随着鲸须生长而沉积的激素，因此，一块鲸须中包含了几十年来单个鲸的生殖史、压力和总体健康状况的详细记录。鲸须还含有碳和氮的特征，可以重建鲸鱼的饮食和迁徙历史。该项目将使用这些新技术来分析从19世纪到20世纪80年代从博物馆收集的可活200年的弓头鲸（Balaena mysticetus）的须鲸，以调查长期的，多年的环境变化对长寿哺乳动物的压力，生长和繁殖的影响。统计建模将把结果置于更广泛的背景下，阐明鲸鱼以及其他长寿哺乳动物如何随着时间的推移对环境变化做出反应。该项目将招募约40名本科生参与史密森尼的研究，培训一名博士后和博士生，在参与的博物馆进行大量公开演讲，涉及阿拉斯加原住民社区，他们的祖先最初收集了标本，并在科学会议和同行评审的出版物中发布结果，从而促进更广泛的社会影响。环境变化对长寿物种造成的生理影响可能持续数年，但缺乏在必要的十年时间尺度上量化这种影响及其对种群的影响的方法。该项目采用最近开发的鲸须分析技术来解决这一数据缺口，测试海洋条件的突然变化对个体的压力、生长和繁殖造成随后多年影响的假设，并且这些信息可用于模拟种群水平对当前和预测的环境变化的反应。该项目利用了博物馆中保存的弓头鲸（Balaena mysticetus）的须鲸标本，选择这些标本的原因是它们的须鲸生长缓慢，寿命特别长（200年），范围大，以及它们在北太平洋冬季和北冰洋夏季栖息地的环境变化。从1859年至1989年收集的56个须鲸标本将以2厘米的间隔采样稳定同位素，以4厘米的间隔采样肾上腺、甲状腺和生殖激素，从而能够以大约每月的分辨率重建几十年来的个体历史。具体目标包括：(1)利用四种激素评估应激生理，确定1977年北太平洋生态体制转变前后幼鱼的一生内分泌史；(2)评估这种压力对幼鱼生长速率的潜在影响；(3)在以不同人为和环境影响为特征的时代，扩展成人压力和繁殖的历史模式的长期数据集；(4)利用扰动的种群后果框架，利用所得数据建立生态变化、个体生理和潜在种群影响之间的联系模型。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。

This project uses new techniques to analyze historical museum specimens of whale baleen (long vertical strips of keratin that grow slowly from a whale's upper jaw) to investigate how environmental change affects long-lived animals. Environmental change can have dramatic effects on wildlife, but these effects often unfold slowly across many years, challenging scientists' ability to gather data across sufficient stretches of time. It has recently been discovered that baleen contains hormones that are deposited as the baleen grows, such that one piece of baleen contains a detailed record of individual whales’ reproductive history, stress and general health across decades. Baleen also contains carbon and nitrogen signatures that enable reconstruction of the whale's diet as well as its migration history. This project will use these new techniques to analyze museum baleen collected from the 1800s to the 1980s from bowhead whales (Balaena mysticetus), which can live 200 years, to investigate long-term, multi-year impacts of environmental change on stress, growth and reproduction in a long-lived mammal. Statistical modeling will put results into a broader context, illuminating how whales, and by extension other long-lived mammals, respond to environmental change over time. The project will engage ~40 undergraduates in Smithsonian-based research, train a postdoc and PhD student, result in numerous public talks at participating museums, involve Native Alaskan communities whose ancestors originally collected the specimens, and distribute results at scientific conferences and in peer-reviewed publications, thus contributing to broader societal impacts.Environmental change causes physiological impacts that can last years in long-lived species, yet there is a dearth of methods for quantifying such impacts and their population effects across the necessary decadal timescales. This project employs recently developed analytic techniques for whale baleen to address this data gap, testing the hypothesis that sudden changes in marine conditions cause subsequent multi-year impacts on stress, growth and reproduction of individuals, and that this information can be used to model population-level responses to current and predicted environmental change. The project utilizes archived museum specimens of baleen from bowhead whales (Balaena mysticetus), selected due to their slow-growing baleen, exceptionally long lifespan (200 years), large range, and well-documented environmental shifts in their North Pacific winter and Arctic Ocean summer habitats. Fifty-six specimens of baleen collected from 1859-1989 will be sampled at 2-cm intervals for stable isotopes and 4-cm intervals for adrenal, thyroid and reproductive hormones, enabling reconstruction of individual histories across decades with approximately monthly resolution. Specific objectives include: (1) Determine lifetime endocrine history of juveniles before and after a well-documented 1977 North Pacific ecological regime shift, using a panel of four hormones to assess stress physiology; (2) Assess potential impacts of such stress on juvenile growth rate; (3) Expand a long-term dataset on historic patterns of stress and reproduction in adults in eras characterized by varying anthropogenic and environmental impacts; (4) Use the resulting data to model linkages between ecological change, individual physiology, and potential population impacts, using the Population Consequences of Disturbance framework.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.