Collaborative Research: ORCC: Saltwater Rising: Understanding how sea level rise affects coastal amphibians

由于海平面上升和风暴潮加剧，气候变化正在增加沿海淡水栖息地的含盐量。无尾动物（青蛙和蟾蜍）在湿地生态系统中起着关键作用，人们认为它们不耐盐水，但最近的合成表明它们比以前认为的更耐盐。该项目提高了我们对两个海平面上升前沿（墨西哥湾和大西洋沿岸）沿海栖息地的无尾猿物种耐盐极限的理解。该项目采用实验方法，调查多种盐度、物种、生命阶段和生物组织水平，提供数据，指导沿海管理者和从业者提高沿海恢复力，防止生物多样性丧失。具体来说，该研究将确定不同物种在盐胁迫下的特定生命阶段死亡率，以预测脆弱的生命阶段和繁殖时间。本研究将确定物种亲缘关系和生态特征是否可以预测盐度脆弱性，并表征一个生命阶段的盐水影响在整个生命阶段的级联程度。最后，本研究旨在了解咸水如何影响跨物种和生命阶段的两栖动物生理，重点关注膜通透性，激素和细胞过程。总之，本研究将产生跨越生命阶段和物种的多种生理、生活史、系统发育和基因组数据集，以确定居住在沿海栖息地的无尾猿物种的耐盐性，为保护行动提供信息并预测气候变化的影响。该项目还将教育学生和公众各种主题，如保护和生理学。气候变化导致的海平面上升正在加剧沿海栖息地的盐碱化。据预测，在未来70年里，美国沿海地区的海平面将上升50到100厘米，东部和墨西哥湾沿岸将面临更大的影响。无尾蛙类，或青蛙和蟾蜍，预计将受到盐度增加的严重影响，因为它们被认为基本上不耐盐水。然而，两栖动物的耐盐性比通常认为的更加多变，这使得海水淹没对沿海社区影响的预测存在不确定性。为了解决这些差距，这项研究将集中在10种已知种群的无尾猿物种，这些物种位于德克萨斯州休斯顿和佐治亚州萨皮罗岛附近海岸线5英里内。这些地区是海平面上升的双重前沿，在海平面适度上升的情况下，预计到2050年，低海拔海岸线和淡水湿地将被淹没。该项目将采用比较的方法来研究高盐度环境下的生活史特征和进化历史如何影响特定阶段的生存，长期的盐水暴露如何影响长期的生长、发育和适应性，以及对盐水暴露的生理反应。这项研究将揭示复杂的生命周期如何影响新环境中的持久性，生理机制如何促进盐水耐受性，以及慢性和急性暴露如何影响生存和持久性。此外，这项研究将为预测随着海平面上升将海水进一步推向上游和内陆，不同沿海物种将如何生存提供基线，这可以指导沿海管理者和从业者提高沿海的弹性，防止生物多样性丧失。该奖项反映了美国国家科学基金会的法定使命，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。

Climate change is increasing the amount of salt of coastal freshwater habitats, driven by sea-level rise and intensified storm surges. Anurans (frogs and toads) play a pivotal role in wetland ecosystems and are presumed to be intolerant of saltwater, but recent syntheses indicate more salt tolerance than previously thought. This project improves our understanding of the limits of salt tolerance in anuran species occupying coastal habitats on two sea level rise fronts (Gulf and Atlantic coasts). The project uses an experimental approach that investigates multiple salinities, species, life stages, and levels of biological organization, providing data that can guide coastal managers and practitioners in improving coastal resilience and preventing biodiversity loss. Specifically, the study will identify life stage-specific mortality from salt stress across species to predict vulnerable life stages and breeding times. This research will determine whether species relatedness and ecological traits can predict salinity vulnerability and characterize the extent that the effects of saltwater at one life stage cascade across life stages. Finally, this study aims to understand how saltwater affects amphibian physiology across species and life stages, focusing on membrane permeability, hormones, and cellular processes. In summary, this research will produce diverse physiological, life history, phylogenetic, and genomic datasets that span across life stages and species to determine the salinity tolerance of anuran species that occupy coastal habitats with the goal of informing conservation actions and predicting climate change impacts. The project will also educate students and the public on various topics such as conservation and physiology. Climate change-driven sea level rise is increasing salinization of coastal habitats. Sea levels along the United States coastlines are predicted to rise between 50 and 100 cm in the next 70 years, with the east and gulf coasts facing intensified impacts. Anurans, or frogs and toads, are expected to be severely affected by salinity increases, as they are considered largely saltwater intolerant. However, salinity tolerance among amphibians is more variable than commonly considered, leaving uncertainty in the predictions of seawater inundation effects on coastal communities. To address these gaps, this research will focus on 10 anuran species with known populations within five miles of coastlines near Houston, Texas and Sapelo Island, Georgia. These locations are dual sea level rise fronts with low-elevation coastlines and freshwater wetlands expected to be inundated by the year 2050 under moderate sea level rise scenarios. The project will use a comparative approach to investigate how life history traits and evolutionary history affect stage-specific survival in higher salinities, how chronic saltwater exposure affects long-term growth, development, and fitness, and the physiological responses to saltwater exposure. This research will inform questions on how complex life cycles affect persistence in novel environments, how physiological mechanisms facilitate saltwater tolerance, and how chronic versus acute exposure affect survival and persistence. Additionally, this research will provide baselines for predicting how different coastal species will fare as sea level rise pushes saltwater further upriver and inland, which can guide coastal managers and practitioners to improve coastal resiliency and prevent biodiversity losses.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.