Collaborative Research: Metabolic habitat barriers imposed on tropical diel vertical migrators

合作研究：对热带昼夜垂直迁徙者施加的代谢栖息地障碍

• 批准号: 2127538
• 负责人: Brad Seibel
• 金额: $ 39.48万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2127538&HistoricalAwards=false
• 关键词: Collaborative; Research; Metabolic; habitat; barriers

This project is seeking to define physiologically-accessible habitat for animals faced with changing ocean conditions. Many oceanic animals migrate daily from warm, oxygenated surface waters at night to deep, cold and hypoxic waters during the daytime, and these migrations play critical roles in oceanic ecology and biogeochemical cycles. Over their depth ranges, migrators face very different ecological and environmental demands that may lead to unique traits that in turn, influence how they respond to a warming ocean where oxygen minimum zones are also expanding. This study is combining ecological and physiological approaches during two expeditions to the Gulf of California. The investigators are measuring metabolic traits in a diverse suite of ocean animals that exhibit vertical migration to determine possible roles of oxygen and temperature in triggering changes in vertical and latitudinal distribution. They are also measuring species distributions in relation to environmental oxygen and temperature to determine ecologically-relevant thresholds of environmental tolerance. The project involves training and experiential learning for graduate and undergraduate students. In addition, engagement with educational experts and artists will generate media and lesson plans to support STEM education and Next Generation Science Standards. These activities leverage the Bermuda Institute of Ocean Sciences’ Databytes and Mid-Atlantic Robotics IN Education (MARINE) programs, designed to improve ocean literacy and technological fluency and targeting students from groups traditionally underrepresented in science. Project products also include a new level for a video game that introduces the concepts of how oxygen minimum zones influence animal distribution.Climate change is driving poleward shifts in the distributions of marine animals. These shifting edges of the range of species habitats are often interpreted as a manifestation of oxygen limitation that is presumed to occur at high water temperatures due to a mismatch between physiological oxygen supply and thermodynamically-driven oxygen demand. However, recent work by the investigators suggests that oxygen supply has evolved to meet demand regardless of temperature. These opposing views predict very different thermal thresholds for range expansion. In this study, the investigators are employing a relationship between metabolic traits to infer a unique temperature sensitivity in tropical diel vertical migrators and to map their metabolically-available habitat in the Eastern Pacific. Specifically, the investigators propose that oxygen supply does not limit metabolism in tropical migrators, even in the oxygen minimum zone. Instead, they contend that the active metabolic rate for tropical migrators is highly sensitive to temperature, and that this creates a barrier to range expansion where the aerobic scope for growth and reproduction is insufficient in cold waters. This temperature sensitivity will also allow migrators to expand poleward to newly available habitat following modest warming, rather than simply being extirpated from their native tropical habitat by excess warming. This hypothesis, if supported, would transform our mechanistic understanding of species’ responses to climate change, amend our predictions of range expansion, and modify our assessment of migrator contributions to oceanic biogeochemical cycles in a warmer future ocean.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.

该项目旨在为面临不断变化的海洋条件的动物定义生理上可进入的栖息地。许多海洋动物每天都会在夜间从温暖、含氧的表层水域迁徙到白天的深海、寒冷和缺氧的水域，这些迁徙在海洋生态和生物地球化学循环中发挥着至关重要的作用。在其深度范围内，迁徙者面临着截然不同的生态和环境需求，这些需求可能会导致独特的特征，进而影响它们如何应对海洋变暖（其中最低含氧区也在扩大）。这项研究结合了两次加利福尼亚湾探险期间的生态和生理方法。研究人员正在测量表现出垂直迁移的多种海洋动物的代谢特征，以确定氧气和温度在触发垂直和纬度分布变化中可能发挥的作用。他们还测量与环境氧气和温度相关的物种分布，以确定与生态相关的环境耐受阈值。该项目涉及研究生和本科生的培训和体验式学习。此外，与教育专家和艺术家的合作将生成媒体和课程计划，以支持 STEM 教育和下一代科学标准。这些活动利用了百慕大海洋科学研究所的 Databytes 和中大西洋机器人教育 (MARINE) 项目，旨在提高海洋素养和技术流畅性，并针对传统上在科学领域代表性不足的群体的学生。项目产品还包括视频游戏的新关卡，该关卡引入了最低氧气区如何影响动物分布的概念。气候变化正在推动海洋动物分布向极地转移。物种栖息地范围的这些变化边缘通常被解释为氧气限制的表现，这种情况被认为是由于生理供氧与热力学驱动的需氧量之间的不匹配而在高水温下发生的。然而，研究人员最近的研究表明，无论温度如何，氧气供应已经能够满足需求。这些相反的观点预测了范围扩展的非常不同的热阈值。在这项研究中，研究人员利用代谢特征之间的关系来推断热带昼夜垂直迁徙者独特的温度敏感性，并绘制它们在东太平洋的代谢可用栖息地。 具体来说，研究人员提出，即使在氧气最低区，氧气供应也不会限制热带迁徙者的新陈代谢。相反，他们认为热带洄游者的活跃代谢率对温度高度敏感，这对范围扩大造成了障碍，因为在冷水中生长和繁殖的有氧范围不足。这种温度敏感性还将使迁徙者能够在适度变暖后向极地扩展至新的可用栖息地，而不是简单地因过度变暖而从其原生热带栖息地灭绝。 这一假设如果得到支持，将改变我们对物种对气候变化反应的机械理解，修正我们对范围扩张的预测，并修改我们对未来海洋变暖时迁徙者对海洋生物地球化学循环贡献的评估。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Unique thermal sensitivity imposes a cold-water energetic barrier for vertical migrators

独特的热敏感性为垂直迁移者提供了冷水能量屏障

• DOI: 10.1038/s41558-022-01491-6
• 发表时间: 2022
• 期刊: Nature Climate Change
• 影响因子: 30.7
• 作者: Seibel, Brad A.;Birk, Matthew A.
• 通讯作者: Birk, Matthew A.