Collaborative Research: Zooplankton restarts in a high-latitude marine ecosystem: species-specific recruitment and development in early spring

合作研究：浮游动物在高纬度海洋生态系统中重新启动：早春物种特异性的补充和发育

• 批准号: 2222592
• 负责人: Russell Hopcroft
• 金额: $ 33.59万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2222592&HistoricalAwards=false
• 关键词: Collaborative; Research; Zooplankton; restarts; latitude

Global climate change and associated extreme weather events are increasingly impacting marine communities at all trophic levels and leading to shifts in the timing of life history events. This project is investigating the annual restart of the spring zooplankton community in the Gulf of Alaska in order to determine the timing of species-specific recruitment and growth. Zooplankton are small pelagic animals that are a critical link between microalgae and protozoans and higher levels in the food web including economically important fishes, birds and marine mammals. While their abundances and species composition have been documented over part of the annual cycle between late spring and fall, this project focuses on winter and early spring. The project integrates traditional methods with modern molecular approaches to characterize the diversity, development, feeding and physiology of zooplankton, especially the early developmental stages of copepods (small crustaceans). The goal is to determine which species are there, how many are present and where they are in the water column, and to reveal indicators of their health. Broader impacts include research training for three graduate students and at least four undergraduates in biological oceanography and physiological ecology. Outreach activities are focusing on broadening the public’s understanding of plankton ecology. An illustrated zooplankton guide for the Gulf of Alaska and plankton module for school teachers and students is being produced in collaboration with the Center for Alaskan Coastal Studies. Other plans include sponsorship of nature-drawing workshops on zooplankton and the production of an Art & Science traveling exhibit. This project is tracking zooplankton population abundances, species composition and developmental stages through the spring restart in a high-latitude fjord in the northern Gulf of Alaska. While the entire zooplankton community is being characterized, the main focus is on the difficult-to-assess early developmental stages of copepods, which dominate the late spring biomass in the region. Three central hypotheses guide the research: 1) high abundances of copepod nauplii are present before any measurable increases in food in surface waters; 2) species diversity increases between winter and spring, with nauplii from large lipid-rich capital-breeding species appearing first, followed by those from income- and hybrid-strategy species and finally nauplii that emerge from dormant eggs; 3) prior to the appearance of food resources, nauplii from capital-breeding species conserve resources by delaying development and entering a state of dormancy in the second and third naupliar stages. The project entails intensive depth-stratified field sampling to characterize the wild community, in combination with laboratory experiments on nauplii to determine their responsiveness to food. The prey are being characterized by measuring chlorophyll a, dietary and prey community DNA sequencing and flow cytometry to establish diversity and abundances. Size-fractionated zooplankton samples are being analyzed using microscopy and community DNA sequencing to ascertain species diversity, developmental stage distribution and abundances. Feeding activity is being measured using dietary DNA sequencing of nauplii followed by comparisons with the prey field. Dormancy in nauplii is being determined by differential gene expression of target genes (RT-qPCR) and high-throughput sequencing of mRNA of individuals (transcriptomics) and community samples (meta-transcriptomics). Short-term and long-term effects of food availability on dormancy, development and growth are being quantified in laboratory experiments. Broader impacts are focused on training of students in interdisciplinary research and state-of-art techniques, and public outreach to introduce plankton ecology to broader audiences.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.

全球气候变化和相关的极端天气事件正在日益影响所有营养级别的海洋群落，并导致生活史事件的时间发生变化。该项目正在调查阿拉斯加湾春季浮游动物群落的年度重新启动情况，以确定特定物种的补充和增长的时间。浮游动物是小型远洋动物，是微藻和原生动物之间的关键纽带，也是食物链中水平较高的生物，包括经济上重要的鱼类、鸟类和海洋哺乳动物。虽然它们的丰度和物种组成已在春末和秋之间的年度周期的一部分被记录在案，但该项目侧重于冬季和早春。该项目将传统方法与现代分子方法相结合，以表征浮游动物的多样性、发育、摄食和生理学，特别是桡足类(小型甲壳类)的早期发育阶段。目标是确定那里有哪些物种，存在多少物种，以及它们在水柱中的位置，并揭示它们的健康指标。更广泛的影响包括对三名研究生和至少四名本科生进行生物海洋学和生理生态学方面的研究培训。外展活动的重点是扩大公众对浮游生物生态的了解。与阿拉斯加海岸研究中心合作，正在为学校教师和学生制作阿拉斯加湾浮游动物图解指南和浮游生物模块。其他计划包括赞助关于浮游动物的自然绘画工作坊，以及制作艺术与科学巡回展览。该项目正在阿拉斯加湾北部高纬度峡湾的春季重启期间跟踪浮游动物种群的丰度、物种组成和发育阶段。虽然正在对整个浮游动物群落进行描述，但主要关注的是难以评估的桡足类早期发育阶段，这些阶段主导着该地区晚春的生物量。这项研究以三个中心假设为指导：1)在表层水域的食物出现任何可测量的增加之前，桡足类无节幼体的丰度就已经存在；2)物种多样性在冬季和春季之间增加，首先出现来自大型富含脂肪的资本繁殖物种的无节幼体，其次是来自收入策略物种和杂交策略物种的无节幼体，最后是从休眠卵子中出现的无节幼体；3)在出现食物资源之前，来自资本繁育物种的无节幼体通过延迟发育并在第二和第三无节幼体阶段进入休眠状态来保护资源。该项目需要密集的深度分层野外采样，以确定野生群落的特征，并结合实验室对无节幼体的实验，以确定它们对食物的反应。通过测量叶绿素a、食物和猎物群落DNA测序和流式细胞术来确定多样性和丰度，以确定猎物的特征。正在使用显微镜和群落DNA测序对不同大小的浮游动物样本进行分析，以确定物种多样性、发育阶段分布和丰度。正在使用无节幼体的食物DNA测序来衡量摄食活动，然后与猎物领域进行比较。无节幼体的休眠是通过靶基因的差异基因表达(RT-qPCR)和对个体(转录组)和群落样本(元转录组)的高通量mRNA测序来确定的。实验室实验正在量化食物供应对休眠、发育和生长的短期和长期影响。更广泛的影响集中在对学生进行跨学科研究和最新技术方面的培训，以及向更广泛的受众介绍浮游生物生态学的公共宣传。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。