Collaborative Research: Physical Mechanisms Driving Food Web Focusing in Antarctic Biological Hotspots

海底峡谷作为海洋生物热点发挥着不成比例的重要作用，对我们理解许多沿海生态系统至关重要。与峡谷相关的生物热点在南极半岛西部沿线持续了数千年，尽管气候变化很大。对南极半岛西部具有代表性的热点帕尔默深峡谷海流的观测表明，表层浮游植物水华进出局部热点的时间尺度为1-2天。这种居住时间与流行的观点相冲突，即与峡谷相关的热点主要由浮游植物维持，这些浮游植物是通过富含营养物质的深水上涌来维持的，这些浮游植物与这些特征有关，这些营养物质促进了浮游植物的生长。相反，这意味着水平海洋环流对于维持这些生物热点可能比通过其物理聚集效应而产生的局部上升流更重要。该项目旨在更好地解决在南极半岛西部峡谷创造和维持集中的生物活动区的因素，并为海洋哺乳动物和鸟类创造当地的觅食区。该项目的重点是分析维持这些生物热点的海洋运输和集中机制，将海洋学与浮游植物和磷虾联系起来，通过食物网向上连接到栖息的捕食者之一企鹅。此外，研究将与来自学区的教师接触，通过将教师及其学生完全融入科学团队，为代表不足和服务不足的学生提供服务。学生将在与项目研究人员相同的时间内使用相同的数据进行自己的研究。揭示维持这些已知热点的基本机制将大大促进我们对海底峡谷与持续的企鹅种群热点之间随生态时间的变化而观察到的联系的理解，并为南极热点如何发挥作用提供一个新的模型。为了了解支持西南极半岛(WAP)持续热点的物理机制，该项目将整合一个建模和现场计划，目标是负责将浮游植物和磷虾生物量转移和集中到已知企鹅觅食地点的过程。在具有代表性的热点帕尔默深峡谷内，该团队将部署一个高频雷达(HFR)海岸表面海流测绘网络，该网络配备独特，可以识别聚集浮游植物和磷虾的漩涡和锋面区域。这项以地球物理研究中心确定的地表特征为中心的实地计划将包括：(1)协调一支滑翔机队，在目标会聚特征的尺度上调查水文学、叶绿素荧光、光学后向散射和主动声学；(2)利用与全球定位系统链接的卫星遥测和时间深度记录器(TDR)精确跟踪企鹅；(3)每周进行小船调查，以自适应地瞄准并跟踪会聚特征，以测量浮游植物、磷虾和水文学。一个高分辨率的物理模型将通过模拟将我们的现场测量推广到WAP沿线的其他已知热点，并确定哪些物理机制导致这些热点的维持。该项目还将通过一个教育项目吸引教育工作者、学生和普通公众参与南极研究和数据分析，该教育项目将促进教与学，并扩大代表不足群体的参与。这种参与包括专业发展研讨会、与公众和课堂的现场联系、学生研究座谈会和项目评估。综合研究和参与将促进我们对区域运输路径和局部深度依赖的集中物理机制在维持这些生物热点方面所起的作用的理解。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。

Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function. To understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots.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.