Linking eco-evolutionary dynamics of thermal adaptation and grazing in copepods from highly seasonal environments

海洋的许多部分正在迅速变暖，但这种变暖将如何影响海洋食物网仍不得而知。桡足类，小型甲壳类动物，是海洋中数量最多的动物；因此，它们在浮游生物的海洋食物网和向鱼类传递能量方面起着至关重要的作用。许多种类的桡足类动物能够选择猎物，比如微小的植物和单细胞的动物。这种选择影响着能量如何在海洋食物网中移动。过去的研究表明，温度的升高应该有利于食草动物而不是食肉动物。该项目正在调查这一预测是否适用于在沿海温带等高度季节性系统中对变暖的遗传适应。这项研究的结果有助于了解和预测海洋生态系统对未来气候条件的反应，以及规划和实施可持续渔业管理计划。其他更广泛的影响包括为高中生和大学生开发学习模块。为K-6年级学生提供的动手科学展览，以及已建立的系列讲座的公开演讲，重点是桡足类动物在沿海栖息地海洋食物网中的作用。预测海洋生物群对气候变化的响应不仅受到对气候变暖如何影响生态相互作用和进化动力学的不完全理解的限制，而且受到这两个因素如何相互作用的限制。桡足类动物在海洋系统中既是浮游植物的食草动物，又是微型浮游动物的捕食者。气温升高可能会导致杂食性桡足类动物的饮食大规模转向更强的食草性，对海洋食物网的结构和初级生产力的控制产生重大影响。然而，热适应可能会缓和甚至抵消这些变化。该项目研究了生态和进化动力学在塑造变暖海洋中放牧和个体适应性方面的相互作用。该项目的主要目标是：1)量化沿海优势桡足类物种热性能曲线的季节变化；2)确定观察到的季节热性能变化是由遗传分化还是表型可塑性引起的；3)评估温度如何影响呼吸和蛋白质合成速率、选择摄食和个体适合度；4)确定热性能曲线的变化如何通过遗传分化和表型可塑性影响温度与食物偏好之间的关系。选择性饲养实验与在广泛温度范围内的产蛋和孵化成功率测量相结合，以测量热效应对饲养选择性和个体适应性的影响。最后，在不同热环境下的人群中，对温度敏感性的遗传分化和表型可塑性进行了研究。该项目的成果有助于预测气候变化下渔业动态的模式参数化。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。

Many parts of the ocean are warming rapidly, but it is still unknown how this warming will affect marine food webs. Copepods, small crustaceans, are the most abundant animals in the ocean; consequently, they play crucial roles in plankton marine food webs and in the transfer of energy to fishes. Many species of copepods are able to choose between prey such as microscopic plants and single-celled animals. The choice affects how energy moves through marine food webs. Past work suggests that increasing temperature should favor herbivory over carnivory. This project is investigating whether this prediction holds in the face of genetic adaptation to warming in highly seasonal systems such as coastal temperate zones. Results from this study are contributing to understanding and predicting the response of marine ecosystems to future climate conditions, as well as for planning and implementing sustainable fisheries management plans. Other broader impacts include the development of learning modules for high school and college students. Hands-on science exhibits for K-6 students and public presentations at established lecture series focus on the role of copepods in marine food webs in coastal habitats. Predicting responses of the oceanic biota to climate change is limited not only by an incomplete understanding of how warming affects ecological interactions and evolutionary dynamics individually, but also by how these two factors interact. Copepods are both grazers of phytoplankton and predators of microzooplankton in marine systems. Increasing temperatures may drive a large-scale shift in the diet of omnivorous copepods towards stronger herbivory, with significant consequences for the structure of marine food webs and the control of primary productivity. However, thermal adaptation may moderate or even nullify these shifts. This project examines the interactive role ecological and evolutionary dynamics plays in shaping grazing and individual fitness in a warming ocean. The main goals of the project are to: 1) quantify seasonal variation in thermal performance curves in dominant coastal copepod species; 2) determine whether observed seasonal variation in thermal performance is caused by genetic differentiation or phenotypic plasticity; 3) assess how temperature affects respiration and protein synthesis rates, selective feeding, and individual fitness; and 4) determine how changes in the thermal performance curve, via both genetic differentiation and phenotypic plasticity, affect the relationship between temperature and food preference. Selective feeding experiments are being paired with measurements of egg production and hatching success across a wide range of temperatures to measure thermal effects on feeding selectivity and individual fitness. Finally, genetic differentiation and phenotypic plasticity on temperature sensitivity is being investigated across populations from environments that differ in their thermal regime. The outcomes of this project contribute to the parameterization of models that forecast fisheries dynamics in response to climate change.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.