RII Track-4: Using Otolith Geochemistry to Understand the Ocean Ecology of a Changing Alaskan Salmon System

全球海洋的高纬度区域正在对大气和其他环境变化作出迅速反应。因此，这些生态系统是了解环境驱动因素和生态系统响应关系的重要模型，为更好地预测全球海洋其他区域如何应对未来的环境变化提供了一个框架。特别令人关切的是海洋生态系统的迅速变化对渔业的影响。海鲜在满足全球人口的粮食安全需求方面发挥着关键作用，是美国许多区域经济的重要基础，特别是对于阿拉斯加等偏远州。2014-2016年间，包括阿拉斯加湾（果阿）在内的北太平洋东部地区经历了有史以来最大的海洋热浪之一。太平洋鲑鱼（Oncorhynchus spp.）对海洋气候变异性和其他环境变化的反应一般没有很好的了解。本研究的目的是通过利用鲑鱼的完整生活史记录，通过水温，代谢活动和饮食的自然标志物捕获的优势，促进对鲑鱼海洋生态学的理解，这些自然标志物基于成年红鲑耳骨或耳石中的氧和碳同位素值。返回阿拉斯加州的铜河。这项研究对于提高高纬度海洋生态系统对快速和前所未有的环境变化的反应的一般知识，以及开发为这一关键的阿拉斯加鲑鱼系统的长期可持续管理提供信息所需的科学信息非常重要。包括阿拉斯加湾（果阿）在内的北太平洋东部经历了有史以来最大的海洋热浪之一。阿拉斯加中南部鲑鱼种群对果阿这些异常海洋气候条件的反应，以及与大量孵化场粉红鲑鱼释放到果阿果阿有关的其他密度依赖性环境变化，变化很大，从威廉王子湾粉红鲑鱼的创纪录回报到（Oncorhynchus gorbuscha）在2015年运行失败的这些相同的股票在2016年，以及运行失败的红鲑鱼（O。2018年12月，在日本东京都新宿区的新宿区。因此，太平洋鲑鱼的果阿似乎是最近，高度异常的环境变化，但是，环境驱动程序和鲑鱼的反应关系尚未正式化。本文所述的研究将填补这一知识空白。这个EPSCoR奖学金项目的目标是在15年的时间里，将返回阿拉斯加铜河的成年红鲑在海洋中的居住期间的耳石和同位素变化联系起来（2004-2018年）与一套环境变量相联系，这些变量捕捉在北太平洋运作的海洋气候和密度相关因素的信号，以及红眼的群体性能特征，包括成年体型和身体状况。时间序列分析将用于正式确定环境驱动因素与铜河红眼的反应之间的关系，以增进高纬度海洋生态系统对迅速和前所未有的环境变化的反应的一般知识，以及所需的科学信息，该奖项反映了NSF的法定使命，并已被认为是值得通过评估使用的支持，基金会的学术价值和更广泛的影响评审标准。

High latitude regions of the global ocean are responding rapidly to atmospheric and other environmental changes. Thus, these ecosystems are important models for understanding environmental driver and ecosystem response relationships, providing a framework for better predicting how other regions of the global ocean might respond to future environmental changes. Of particular concern are the impacts of rapid marine ecosystem changes to fisheries. Seafood plays a key role in meeting the food security needs of global human populations and is a critical foundation of many regional economies in the United States, particularly for remote states such as Alaska. Between 2014-2016, the eastern sector of the North Pacific Ocean including the Gulf of Alaska (GOA) experienced one of the largest marine heatwaves ever recorded. How the ocean ecology of Pacific salmon (Oncorhynchus spp.) responds to ocean-climate variability and other environmental changes is generally not well understood. The purpose of this study is to advance an understanding of the ocean ecology of salmon by taking advantage of the complete life history record captured by natural markers of water temperature, metabolic activity, and diet based on oxygen and carbon isotope values in the ear bones, or otoliths, of adult sockeye salmon (O. nerka) returning to the Copper River, Alaska. This research is important for advancing the general knowledge of high latitude marine ecosystem response to rapid and unprecedented levels of environmental change, as well as developing the scientific information needed to inform the long-term sustainable management of this key Alaskan salmon system.Between 2014-2016, the eastern sector of the North Pacific Ocean including the Gulf of Alaska (GOA) experienced one of the largest marine heatwaves ever recorded. Responses by southcentral Alaskan salmon stocks to these anomalous ocean-climate conditions in the GOA, and other density-dependent environmental changes related to the release of significant numbers of hatchery pink salmon to the GOA, have been highly variable and range from record returns by Prince William Sound pink salmon (Oncorhynchus gorbuscha) in 2015 to run failures by these same stocks in 2016, as well as run failures by sockeye salmon (O. nerka) returning to the nearby Copper River system in 2018. Thus, Pacific salmon of the GOA appear to be responding to recent, highly anomalous environmental changes, however, environmental driver and salmon response relationships have not been formalized. The research described here will fill this knowledge gap. The goal of this EPSCoR Fellowship project is to relate otolith and isotope variability during ocean residency of adult sockeye salmon returning to the Copper River, Alaska, over a 15-year period (2004-2018) to a suite of environmental variables that capture signals of ocean-climate and density-dependent factors operating in the North Pacific Ocean, as well as population performance traits of sockeye including adult body size and body condition. Time series analysis will be used to formalize relationships between environmental drivers and responses by Copper River sockeye to advance the general knowledge of high latitude marine ecosystem response to rapid and unprecedented levels of environmental change, as well as the scientific information needed to inform the long-term sustainable management of this key Alaskan salmon system.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.