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: 2127299
• 负责人: Amy Maas
• 金额: $ 29.77万
• 依托单位: Bermuda Institute of Ocean Sciences (BIOS), Inc.
• 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=2127299&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访问的栖息地。许多海洋动物每天从夜间温暖、含氧的表层沃茨迁移到白天寒冷、缺氧的沃茨，这些迁移在海洋生态和海洋地球化学循环中起着关键作用。在它们的深度范围内，迁徙者面临着非常不同的生态和环境需求，这可能导致独特的特征，反过来影响它们如何应对海洋变暖，其中氧气最小区域也在扩大。本研究是结合生态和生理的方法，在两次考察加州湾。研究人员正在测量一系列表现出垂直迁移的海洋动物的代谢特征，以确定氧气和温度在引发垂直和纬度分布变化方面的可能作用。他们还测量与环境氧气和温度有关的物种分布，以确定与生态有关的环境耐受性阈值。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接触将产生媒体和课程计划，以支持STEM教育和下一代科学标准。这些活动利用百慕大海洋科学研究所的数据字节和中大西洋机器人教育方案，旨在提高海洋知识和技术熟练度，并针对传统上在科学领域代表性不足的群体的学生。项目产品还包括一个视频游戏的新关卡，该游戏介绍了氧气最低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限制的表现，这种氧限制被认为是在高水温下由于生理氧供应和呼吸驱动的氧需求之间的不匹配而发生的。然而，研究人员最近的工作表明，氧气供应已经发展到无论温度如何都能满足需求。这些相反的观点预测了非常不同的范围扩展的热阈值。在这项研究中，研究人员正在利用代谢性状之间的关系来推断热带昼夜垂直迁移者独特的温度敏感性，并绘制其在东太平洋的代谢可用栖息地。 具体来说，研究人员提出，氧气供应不会限制热带迁徙者的新陈代谢，即使是在氧气最低区。相反，他们认为，热带迁徙者的活跃代谢率对温度高度敏感，这对范围扩张造成了障碍，因为在寒冷的沃茨，生长和繁殖的有氧范围不足。这种温度敏感性也将使迁徙者在适度变暖后向极地扩展到新的栖息地，而不是简单地被过度变暖从其原生的热带栖息地灭绝。 这一假设，如果得到支持，将改变我们对物种对气候变化的反应的机械理解，修正我们对范围扩张的预测，并修改我们对未来海洋变暖中迁移者对海洋生物地球化学循环的贡献的评估。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知识价值和更广泛的影响审查标准进行评估来支持。