RUI: Collaborative Research: Linking physiological thermal thresholds to the distribution of lobster settlers and juveniles

RUI：合作研究：将生理热阈值与龙虾定居者和幼体的分布联系起来

• 批准号: 1947639
• 负责人: Douglas Rasher
• 金额: $ 26.67万
• 依托单位: Bigelow Laboratory for Ocean Sciences
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947639&HistoricalAwards=false
• 关键词: RUI; Collaborative; Research; Linking; physiological

Temperature is one critical factor that determines the distribution of marine organisms. However, in many cases temperature ranges (thermal tolerances) are only known for adults, but not for the immature stages that transition from the plankton to the bottom. This study is testing how temperature affects where larvae are settling. The American lobster (Homarus americanus) in the Gulf of Maine is serving as a model system to measure the thermal tolerance of the larvae and link this to the distribution of young lobsters in the field. Presently, lobster larvae are more likely to experience relatively cold temperatures than heat stress and larval settlement appears to be restricted to warmer shallow waters by a sensitivity to temperatures below 12°C. As water temperature has increased, settlement and juvenile distribution have expanded into deeper waters suggesting a release from cold stress. This project is advancing the understanding of shifting species distributions in response to increasing ocean temperatures by exploring thermal sensitivity in wild-caught larvae for the first time. This information is providing thermal thresholds for modeling larval viability in response to climate change scenarios. Understanding the larvae’s responses to temperature is fundamental to predicting the impact of climate change on one of the most valuable commercial fisheries in North America. The project is supporting training of undergraduate interns and a master’s student from small colleges (Hood College and University of New England) and connecting them with a research institution (Bigelow Laboratory for Ocean Sciences). Teacher training is occurring in collaboration with the Marine Science Center at the University of New England. Results from this study are being shared with stakeholders and contributing to science-based management of the lobster fishery.This project is the first to examine how thermal stress on a larval stage determines juvenile distributions using a combination of correlative and experimental approaches that includes measuring biochemical stress indicators in larvae deployed in natural field habitats. The central hypothesis is that the physiology of individual planktonic larvae controls meso-scale settlement patterns in the field. The goal is to ascertain if there is a causal relationship between the underlying physiology and thermal sensitivity of the organism and the distribution of early life stages. Larval supply, settlement and juvenile abundances will be assessed at different depths with temperatures above and below the proposed minimum temperature threshold of 12°C for larvae. Laboratory experiments using conventional methods are determining thermal tolerances in wild-caught larvae and how they change with ontogeny. The upper and lower thermal optima are being resolved using multiple physiological parameters such as measurements of oxygen consumption and aerobic scope, and biochemical assays of thermal stress (HSP70, AMPK, and SIRT). To link physiology to settlement patterns, caged stage IV larvae and V juveniles are being deployed in the field at sites with temperatures above and below 12°C. Lethal and sub-lethal effects on caged lobsters are being evaluated through measures of growth, mortality and biochemical markers of thermal stress. This is the first study to focus on the thermal tolerance of wild larvae, which has broad implications for understanding settling in marine invertebrate larvae.This project is jointly funded by Biological Oceanography (OCE) and the Established Program to Stimulate Competitive Research (EPSCoR).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.

温度是决定海洋生物分布的一个关键因素。然而，在许多情况下，温度范围(热容忍度)只为成年人所知，而不是从浮游生物过渡到海底的未成熟阶段。这项研究正在测试温度如何影响幼虫的栖息地。缅因湾的美国龙虾(Homarus Americanus)是测量幼体耐热性的模型系统，并将其与田野中幼龙虾的分布联系起来。目前，龙虾幼体更有可能经历相对较低的温度而不是热应激，幼体的定居似乎被限制在较温暖的浅海，因为对12°C以下的温度很敏感。随着水温的升高，定居和幼体分布扩大到更深的水域，这表明冷应激得到释放。该项目通过首次探索野生捕获幼虫的热敏感性，促进了对物种分布随海洋温度上升而变化的理解。这些信息为模拟幼虫的生存能力提供了温度阈值，以应对气候变化的情景。了解幼虫对温度的反应对于预测气候变化对北美最有价值的商业渔业之一的影响至关重要。该项目支持对来自小型学院(胡德学院和新英格兰大学)的本科生实习生和一名硕士学生的培训，并将他们与一个研究机构(毕格罗海洋科学实验室)联系起来。教师培训正在与新英格兰大学的海洋科学中心合作进行。这项研究的结果正在与利益攸关方分享，并为龙虾渔业的科学管理做出贡献。该项目是第一个使用相关和实验相结合的方法来研究幼体阶段的热应激如何决定幼体分布的项目，其中包括测量部署在自然野外生境中的幼体的生化应激指标。中心假设是，个体浮游幼虫的生理控制着田野中尺度的定居模式。目的是确定生物体的潜在生理和热敏感性与早期生命阶段的分布之间是否存在因果关系。将在不同深度评估幼虫的供应、定居和幼体丰度，温度高于和低于拟议的幼虫最低温度阈值12摄氏度。使用常规方法的实验室实验正在确定野生捕获幼虫的耐热性，以及它们如何随着个体发育而变化。使用多种生理参数，如耗氧量和有氧范围的测量，以及热应激的生化分析(HSP70、AMPK和SIRT)，可以确定上下限的最优温度。为了将生理学与定居模式联系起来，笼养的第四阶段幼体和V型幼体正被部署在温度高于和低于12°C的现场。正在通过测量生长、死亡率和热应激的生化标记来评估笼养龙虾的致死和亚致死影响。这是第一项关注野生幼虫耐热性的研究，这对理解海洋无脊椎动物幼虫的栖息具有广泛的意义。该项目由生物海洋学(OCE)和既定的刺激竞争研究计划(EPSCoR)联合资助。该奖项反映了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。