ORCC: Collaborative Research: Mechanisms underpinning the unusual, high CO2 sensitivity of sand lances, key forage fishes on the Northwest Atlantic Shelf

海洋变暖和酸化是人为气候变化的直接、可预测的后果，可能对海洋生物造成巨大但尚未充分了解的后果。到目前为止，大多数测试的鱼类对海洋酸化只表现出轻度敏感，但沙矛鱼是个例外。沙矛鱼是一种小型的、类似鳗鱼的鱼群，在温带到极地的生态系统中作为海鸟和哺乳动物的食物具有巨大的重要性。最近的研究结论性地表明，许多沙矛胚胎在预测的未来海洋条件下难以发育和孵化。该项目使用现代实验和分子工具来准确理解为什么沙矛胚胎如此异常敏感，以及哪些基因和酶对此负责。基因还将揭示某些特定的基因型是否对变暖和酸化不太敏感，然后可以用来预测物种是否会随着时间的推移而进化得更耐受。另一个重要的目标是测试一个密切相关的沙矛物种，以找出是否高气候敏感性可能是普遍关注的这一重要群体的饲料鱼。该项目结合了创新的生态，进化和基因组研究，以帮助社会预测即将到来的海洋生态系统的变化在21世纪世纪，同时装备下一代科学家所需的工具和专业知识，在未来的挑战取得成功。该项目还为来自康涅狄格州贫困学校的高中生创造了机会，让他们陪同团队前往Stellwagen Bank国家海洋保护区进行砂枪采样。最近的两项研究北方沙矛（Ammodytes lance），一个关键的饲料鱼在近海沙洲横跨西北大西洋大陆架，已经有力地证明，预测未来的二氧化碳条件诱导一些最严重的减少胚胎存活率和孵化成功率测试的鱼类。该项目有四个目标，揭示这种不寻常的高二氧化碳敏感性的机制，以及这种现象的普遍性和遗传基础。[1]第一次，我们将饲养A。在析因CO2 ×温度条件下，从野生产卵到晚期幼虫阶段产生的沙矛鱼后代，以测试沙矛鱼幼虫是否像胚胎一样对CO2敏感。[2]我们将首次使用转录组学工具（RNAseq，RT-qPCR）来阐明导致“CO2受损孵化”的机制，特别关注孵化酶，以更好地了解新发现的鱼类高CO2死亡机制。[3]现代基因组学方法（低覆盖率全基因组测序;等位基因频率变化，相关性分析）将揭示高CO2敏感性是否具有砂枪的遗传基础，因此可以进化。[4]并首次将CO_2 ×温度实验扩展到一个同类--美国砂枪（A. americanus），这提供了一个重要的科学对比近岸与近海物种的二氧化碳敏感性，并将产生关键的见解是否高二氧化碳敏感性是一个更广泛的关注在砂矛家庭。 该奖项由BIO/IOS生物应对气候变化计划和GEO/OCE生物海洋学计划共同资助。该奖项反映了NSF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。

Ocean warming and acidification are direct, predictable consequences of anthropogenic climate change with likely vast but still insufficiently understood consequences for marine life. So far, most tested fish species appear only mildly sensitive to ocean acidification, but sand lances are an exception. Sand lances are small, eel-like, schooling fishes of enormous importance as food for seabirds and mammals in temperate to polar ecosystems. Recent research conclusively demonstrated that many sand lance embryos have trouble developing and hatching under predicted future ocean conditions. This project uses modern experimental and molecular tools to understand exactly WHY sand lance embryos are so unusually sensitive and which genes and enzymes are responsible for this. Genes will also reveal whether some specific genotypes are less sensitive to warming and acidification, which can then be used to predict whether the species could evolve to be more tolerant over time. Another important objective is to test a closely related sand lance species to find out whether the high climate sensitivity might be of general concern in this important group of forage fishes. This project combines innovative ecological, evolutionary, and genomic research to help society anticipate looming marine ecosystem changes in the 21st century, while equipping the next generation of scientists with the needed tools and expertise to succeed in the challenges ahead. The project also creates opportunities for high school students from underprivileged Connecticut schools to accompany the team on sand lance sampling trips to Stellwagen Bank National Marine Sanctuary. Two recent studies on Northern sand lance (Ammodytes dubius), a key forage fish on offshore sand banks across the Northwest Atlantic shelf, have robustly demonstrated that predicted future CO2 conditions induce some of the most severe reductions in embryo survival and hatching success seen yet among tested fish species. This project has four objectives for revealing the mechanisms underpinning this unusual, high CO2-sensitivity as well as the ubiquity and genetic basis of this phenomenon. [1] For the first time, we will rear A. dubius offspring produced from wild spawners to late larval stages at factorial CO2 × temperature conditions to test whether sand lance larvae are as CO2-sensitive as embryos. [2] For the first time, we will use transcriptomic tools (RNAseq, RT-qPCR) to elucidate mechanisms causing ‘CO2-impaired hatching’, focusing specifically on hatching enzymes, to better understand a newly discovered mortality mechanism due to high CO2 in fishes. [3] Modern genomic approaches (low-coverage whole genome sequencing; allele frequency shifts, relatedness analyses) will reveal whether high CO2-sensitivity has a genetic basis in sand lance and could therefore evolve. [4] And for the first time, we will extend CO2 × temperature experiments to a congener, the American sand lance (A. americanus), which provides an important scientific contrast between nearshore vs. offshore species CO2-sensitivities and will yield critical insights whether high CO2-sensitivity is a wider concern within the sand lance family. This award was co-funded through the BIO/IOS Organismal Responses to Climate Change Program and the GEO/OCE Biological Oceanography Program.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.