LTER: Beaufort Sea Lagoons: An Arctic Coastal Ecosystem in Transition

该项目将沿着阿拉斯加北极海岸线建立一个新的长期生态研究(LTER)地点。基于乌特恰格维克(前身为巴罗)、死马和卡托维克的研究将解决海岸线侵蚀和流入沿海海洋的淡水在季节性、年度和更长时间范围内的变化如何影响近岸食物网。研究将与当地利益相关者团体和美国鱼类和野生动物服务机构合作进行。这项研究将促进我们对陆地和海洋条件输入的物质如何相互作用影响沿海食物网的基本理解。它还将使我们能够跟踪和了解：1)自然气候周期如何影响北极的沿海生态系统，以及2)气候变化的影响，如永久冻土融化、降水制度的变化和海冰的减少如何改变沿海生态系统。阿拉斯加北极海岸线的近岸食物网支持大量的迁徙鱼类和水禽，这对阿拉斯加北部伊尼乌皮特社区的养殖至关重要。该LTER站点的研究将建立一个框架，以预测未来变化对沿海生态系统的影响，这些变化是这些社区非常关注的。LTER计划的结果也将引起更广泛的科学界的兴趣，他们正在努力了解北极变化和全球碳循环之间的潜在联系。最后，LTER项目包括通过研究生和本科生的参与、博士后指导、在卡克托维克继续一个非常成功的暑期科学K-12项目以及在乌特恰格维克建立一个平行的K-12项目来坚定地致力于教育。此外，该项目还将雇用居住在乌特恰格维克和卡克托维克的本地高三学生或刚毕业的学生作为实地研究助理。最近的研究表明，需要扩大理解控制食物网络结构的因素的生态框架，以包括时间强迫。更具体地说，越来越多的证据表明，季节性不同资源的不同可获得性对于确定营养联系和维持食物网的稳定性和弹性至关重要。这一新的LTER计划将使用阿拉斯加博福特海岸的泻湖作为实验单位来测试这一概念，并将其扩大到包括更长时间范围内的时间变化。博福特泻湖是测试这一概念的理想之选，因为它们经历了季节周期的极端变化，而季节周期现在受到气候变化驱动的快速方向性变化的影响。我们的首要问题是：在季节性、年际、年代际和更长的时间范围内，泻湖和海水之间陆地输入、当地生产和交换的变化如何通过对碳和氮循环、微生物和后生动物群落组成以及营养联系的影响来相互作用来控制食物网络结构？在没有边缘湿地的情况下，北冰洋泻湖提供了一个研究这些相互作用的独特机会，而边缘湿地往往调节着其他泻湖系统中的陆地-海洋相互作用。此外，由于海冰对海岸地貌的影响叠加在海流、海平面和海浪的影响上，障碍岛地貌对泻湖和开阔海洋之间的水交换起着强有力的控制作用，在北极具有高度的动态性。因此，陆地和泻湖生态系统之间的输入之间的联系更加直接，泻湖和开阔海洋之间的水交换比典型的低纬度系统更加多变。具体的研究地点将设在埃尔森泻湖(博福特西部)、辛普森泻湖和斯蒂芬森海湾(博福特中部)，以及卡克托维克和贾戈泻湖(博福特东部)。LTER将包括在覆冰、破冰和开阔水域期间的季节性野外工作，还包括为连续测量关键的生物地球化学和水文参数而部署的传感器。

This project will establish a new Long Term Ecological Research (LTER) site along the Alaskan Arctic coastline. Research based out of Utqiagvik (formerly Barrow), Deadhorse, and Kaktovik will address how changes in shoreline erosion and freshwater inflows to the coastal ocean over seasonal, annual, and longer timeframes influence near-shore food webs. Research will be conducted in collaboration with local stakeholder groups and the U.S. Fish and Wildlife Service. This research will advance our fundamental understanding of how input of materials from land and oceanographic conditions interact to influence coastal food webs. It will also allow us to track and understand: 1) how natural climate cycles influence coastal ecosystems in the Arctic, and 2) how climate change effects such as permafrost thaw, shifting precipitation regimes, and losses of sea ice alter coastal ecosystems. Near-shore food webs along the Alaskan Arctic coastline support large populations of migratory fish and waterfowl that are essential to the culture of Iñupiat communities of northern Alaska. The research at this LTER site will create a framework for anticipating the impacts of future changes on the coastal ecosystem that are of great concern to these communities. Results from this LTER program will also be of interest to a broader science community that is working to understand potential connections between Arctic change and global carbon cycling. Finally, this LTER project includes a strong commitment to education through graduate and undergraduate student involvement, post-doctoral mentoring, continuation of a very successful Summer Science K-12 Program in Kaktovik, and establishment of a parallel K-12 program in Utqiagvik. In addition, this project will employ native high school seniors or recently graduated students living in Utqiagvik and Kaktovik as field research assistants. Recent studies suggest that the ecological framework for understanding what controls food web structure needs to be expanded to include temporal forcing. More specifically, there is mounting evidence that differential availability of seasonally-distinct resources is critical for defining trophic linkages and maintaining stability and resilience of food webs. This new LTER program will use lagoons along the Alaskan Beaufort Sea coast as experimental units to test this concept, and broaden it to include temporal variations over longer timeframes. The Beaufort lagoons are ideal for testing this concept because they experience extreme variability in seasonal cycles, which are now subject to rapid directional shifts driven by climate change. Our overarching question is: How do variations in terrestrial inputs, local production, and exchange between lagoon and ocean waters over seasonal, inter-annual, inter-decadal, and longer timeframes interact to control food web structure through effects on carbon and nitrogen cycling, microbial and metazoan community composition, and trophic linkages? Arctic lagoons provide a unique opportunity to study these interactions in the absence of fringing wetlands that often modulate land-ocean interactions in other lagoon systems. In addition, barrier island geomorphology, which exerts a strong control on water exchange between lagoons and the open ocean, is highly dynamic in the Arctic because sea-ice effects on coastal geomorphology are superimposed on the effects of currents, sea level, and waves. Thus, connections between inputs from land and lagoon ecosystems are more direct, and water exchanges between lagoons and the open ocean are more variable than is typical of lower latitude systems. Specific study sites will be located in Elson Lagoon (western Beaufort), Simpson Lagoon and Stefansson Sound (central Beaufort), and Kaktovik and Jago lagoons (eastern Beaufort). The LTER will include seasonal field work during ice covered, ice break-up, and open water periods and also include sensor deployments for continuous measurements of key biogeochemical and hydrographic parameters.