Collaborative Research: Shifting the Hypoxia Paradigm - New Directions to Explore the Spread and Impacts of Ocean/Great Lakes Deoxygenation

由于气候变暖，海洋氧气损失(脱氧)正在增加。这种变暖，加上营养物质的负载，正在导致许多海洋和淡水系统经历越来越多的缺氧(低氧)事件，持续时间更长，强度更大。对鱼类和渔业的影响很难量化；由于缺乏长期暴露指标，直接观察受到了挑战。该团队成功地改进了在鱼类耳石(耳石)中使用鱼类化学生物标记物来直接评估鱼类终身低氧暴露的方法。该项目将利用这些发现寻找更多的生物标志物和模型，扩大我们对低氧如何影响鱼类及其食物网、污染物转移和包括经济影响在内的生态系统服务的理解。该项目包括一种培训学生进行科学交流的独特方式，提出了这样一个问题：在提高公众意识和理解方面，什么形式的媒体和关于脱氧的“信息策略”最有效？学生们正在开发PlanetForward的Storyfest的参赛作品，这是一项讲述引人入胜的故事以促进对环境的理解和解决方案的比赛。来自历史上代表性不足、经济困难背景的学生尤其受到欢迎。调查人员将与区域、国家和国际管理机构以及其他相关利益攸关方团体接触，共享信息。该项目包括一套新颖的、相互关联的食物网跨学科研究，以及生态系统服务评估。本项目探讨的主题问题是：1.低氧如何改变鱼类的栖息地利用？2.低氧改变的栖息地利用和栖息地生产力如何改变食物网？3.低氧如何影响/增强甲基汞的营养转移？4.低氧诱导的食物网变化如何影响水生生态系统服务？这套相互关联的研究将使用耳石和眼镜片的化学分析，结合肌肉组织的化学分析(问题1和3)、监测时间序列提供信息的生理结构食物网建模(问题2和4)，以及处理生态系统服务的范围确定讲习班(问题4)。研究人员正在使用“跨流域”的比较方法来研究特定系统的反应，研究伊利湖、波罗的海和墨西哥湾河口的鱼类。他们研究了每个系统中代表不同程度底栖生物依赖的三个物种，以辨别对日益缺氧的环境的不同反应。这项研究为各种生物对缺氧的反应及其对生态系统功能的影响提供了新的见解。这一奖项反映了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。

Ocean oxygen loss (deoxygenation) is increasing due to climate warming. This warming, together with nutrient loading, is causing many marine and freshwater systems to experience increasing episodes of hypoxia (low oxygen) of greater duration and intensity. Impacts on fish and fisheries have been difficult to quantify; direct observation has been challenged by a lack of long-term exposure indicators. This team has successfully refined the use of fish chemical biomarkers in fish otoliths (earstones) to directly assess lifetime hypoxia exposure in fishes. This project will those findings to look for additional biomarkers and models, to expand our understanding of how hypoxia affects fish and their food webs, contaminant transfers, and ecosystem services including economic impacts. The project includes a unique way of training students in science communication, posing the question: What forms of media and "messaging strategies" about deoxygenation are most effective at raising public awareness and understanding? Students are developing entries for PlanetForward's Storyfest, which is a contest to tell compelling stories to foster environmental understanding and solutions. Students from historically underrepresented, economically disadvantaged backgrounds are particularly sought out to participate. The investigators will engage with regional, national, and international management agencies and other relevant stakeholder groups to share information.This project encompasses a novel, linked set of interdisciplinary studies of food webs, and ecosystem services assessment. The thematic questions explored in this project are: 1. How does hypoxia alter habitat use for fishes? 2. How does hypoxia-altered habitat use and habitat productivity change food webs? 3. How does hypoxia affect/enhance trophic transfer of methylmercury? 4. How do hypoxia-induced changes in food webs affect aquatic ecosystem services? The set of linked studies will employ chemical analyses of otoliths and eye lenses, combined with chemical analyses of muscle tissues (Questions 1 and 3), physiologically-structured food web modeling informed by monitoring time-series (Questions 2 and 4), and a scoping workshop to address ecosystem services (Question 4). The investigators are using a "trans-basin" comparative approach to system-specific responses, studying fishes in Lake Erie, the Baltic Sea, and a Gulf of Mexico estuary. They study three species from each system that represent different degrees of benthic reliance, to discern differential responses to the increasingly hypoxic environment. This research provides novel insight about variable biotic responses to oxygen loss and the impacts on ecosystem functioning.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.