Collaborative Research: Linking ion transport, energetics and species distributions in freshwater ecosystems

这个国家的河流和湖泊的含盐量越来越高，这是用盐度来衡量的。其中一些变化与当地人类活动有关，另一些则与更广泛的气候变化有关。盐度的增加预计会产生重要影响，因为许多水生生物是在低盐度环境中进化的，需要低盐度环境。生态学家报告说，盐度的增加会对某些水生生物产生不利影响（例如，水生昆虫，如蜉蝣，是本项目的重点），具有重要的生态意义，是鱼类和鸟类的主要食物来源。因此，盐度的适度增加会对淡水生态系统的生物多样性和功能产生重大影响。这个项目旨在更好地了解不同的水生昆虫物种在不同盐度的沃茨中茁壮成长的能力如何以及为什么会有所不同。这项研究将促进人们对盐度影响水生昆虫代谢、生长和生存的生理机制的理解，并最终影响它们的分布和丰度。项目成果将帮助地方、部落、州和联邦水资源机构及其成员和利益相关者更好地解释水生昆虫的监测数据，这些数据被广泛用作水质和生态条件的指标。 该项目将支持和培训至少三名研究生和几名本科生研究人员，研究人员将为K-12与水质和生态生理学相关的课程开发做出贡献。该项目将使一种新的蜉蝣模式物种暴露于短期和长期的盐度梯度，以确定基因表达模式，耗氧量，血淋巴化学，和鳃的生理学联系到健康的措施。使用比较方法，研究人员将测试这一假设，即在稀释环境中离子吸收的效率和在富含离子的环境中减少过量离子吸收的能力是可以塑造盐度生态位的关键调节特征。研究人员进一步假设，离子运输的能量成本与温度相互作用，影响生长，繁殖力和死亡率，以定义物种特定的盐度生态位，其在自然界中的表达可以从实地调查数据的生态位分析中观察到。这项研究将大大促进人们对盐度的自然变化和人类引起的盐度变化如何在一个越来越咸的世界中对生物体性能和物种分布做出贡献的理解。通过整合不同层次的生物组织（基因到生物多样性模式）以及实验室和实地工作，该项目将大大促进生理学和宏观生态学的综合。该项目还将帮助建立和评估一个有前途的和需要的水生昆虫物种模型，并将提供跨类群的水生昆虫调节差异的基本理解，这将为水生昆虫作为环境变化的生态指标的使用提供信息。研究生和本科生受训人员将得到支持，高中教师将进行夏季研究并开发相关课程，将开发和测试K-12科学课程，其中包括水质的科学，管理和政策方面，该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的学术价值和更广泛的影响审查标准。

The Nation's streams and lakes are growing increasingly salty, as measured by salinity. Some of these changes are associated with local human activities, and some are associated with broader climate changes. Increases in salinity are expected to have important impacts because many aquatic organisms evolved in and require low-salinity environments. Ecologists report that increases in salinity adversely affect some groups of aquatic organisms (e.g., aquatic insects such as mayflies, a focus of this project) that are ecologically important and serve as a primary food source for fishes and birds. Thus, modest increases in salinity could greatly affect both the biodiversity and functioning of freshwater ecosystems. This project is designed to better understand how and why different aquatic insect species vary in their ability to thrive in waters of different salinity. The research will advance understanding of the physiological mechanisms by which salinity affects the metabolism, growth, and survival of aquatic insects, and, ultimately, their distributions and abundance. Project results will help local, tribal, state, and federal water resource agencies and their constituents and stakeholders better interpret monitoring data on aquatic insects, which are widely used as indicators of water quality and ecological conditions. At least three graduate students and several undergraduate researchers will be supported and trained in the project, and the investigators will contribute to K-12 curriculum development related to water quality and ecological physiology.The project will expose a new mayfly model species to short-term and long-term salinity gradients to establish how gene expression patterns, oxygen consumption, hemolymph chemistry, and gill physiology link to measures of fitness. Using comparative methods, the researchers will test the hypothesis that the efficiency of ion uptake in dilute environments and the ability to curtail excessive ion uptake in ion-rich environments are key osmoregulatory characteristics that can shape salinity niches. The investigators further hypothesize that the energetic costs of ion transport interact with temperature to influence growth, fecundity, and mortality to define species-specific salinity niches, the expression of which in nature can be observed from niche analyses of field survey data. The study will significantly advance understanding of how both natural variation in salinity and human-induced changes in salinity contribute to organismal performance and species distributions in an increasingly salty world. By integrating different levels of biological organization (genes to biodiversity patterns) and laboratory and field work, the project should significantly advance the synthesis of physiology and macroecology. The project will also help establish and evaluate a promising and needed model aquatic insect species, and will provide foundational understanding of osmoregulation differences across taxa that will inform the use of aquatic insects as ecological indicators of environmental change. Graduate and undergraduate student trainees will be supported, high-school teachers will conduct summer research and develop relevant curricula, K-12 science curricula that integrate science, management, and policy aspects of water quality will be developed and tested, and public outreach workshops will be held for federal and state agencies.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.