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

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（耐热性）只为成年人所知，而不是从浮游生物过渡到底部的未成熟阶段。这项研究正在测试温度如何影响幼虫定居的地方。缅因州海湾的美洲龙虾（Homarus americanus）是一个模型系统，用于测量幼虫的耐热性，并将其与野外幼龙虾的分布联系起来。 目前，龙虾幼虫更可能经历相对寒冷的温度而不是热应激，幼虫定居似乎因对12°C以下的温度敏感而被限制在较温暖的浅水沃茨。随着水温的升高，定居点和幼鱼分布已扩展到更深的沃茨，表明从冷胁迫中释放。该项目正在通过首次探索野生捕获的幼虫的热敏感性，推进对海洋温度升高引起的物种分布变化的理解。这些信息为模拟气候变化情景下的幼虫生存能力提供了温度阈值。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。该项目正在支持培训小型学院（胡德学院和新英格兰大学）的本科实习生和一名硕士生，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。教师培训是与新英格兰大学海洋科学中心合作进行的。这项研究的结果正在与利益相关者分享，并有助于科学管理的龙虾fisher.This项目是第一个研究如何热应力对幼虫阶段决定少年的分布使用相关和实验的方法相结合，包括测量生化应激指标部署在自然领域栖息地的幼虫。中心的假设是，生理学的个别adaptonic幼虫控制中尺度的解决方案在该领域。目的是确定生物体的基本生理学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。将在温度高于和低于拟议的12摄氏度幼虫最低温度阈值的不同深度评估幼虫供应、定居和幼虫丰度。使用传统方法的实验室实验正在确定野外捕获的幼虫的耐热性以及它们如何随着个体发育而变化。使用多个生理参数，如耗氧量和有氧范围的测量，以及热应激的生化测定（HSP 70，AMPK和SIRT），正在解决上限和下限热最佳值。为了将生理学与定居模式联系起来，将第四阶段的笼中幼虫和第五阶段的幼鱼部署在温度高于和低于12°C的地点。目前正在通过测量生长、死亡率和热应激的生化标志物来评估对笼中龙虾的致死和亚致死影响。这是第一个关注野生幼虫耐热性的研究，该项目由生物海洋学（OCE）和刺激竞争研究的既定计划（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知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

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.