LTER: CCE-LTER Phase III: Ecological Transitions in an Eastern Boundary Current Upwelling Ecosystem

上升区是最具生产力的海洋生态系统之一。加州海流生态系统(CCE)LTER的研究区域是加州海流系统(CCS)的南部部分，CCS是一个主要的上升流生物群，在那里，长达67年的加州渔业合作调查(CalCOFI)计划提供了表征自然气候变异性和渐进变化的基本信息。CCE站点跨越生物地理边界区域，因此是气候变化的早期哨兵；显示了与北太平洋大部分地区相关的低频变化；是CCS大多数上层鱼类生物量的首选产卵地点；在短地理距离内显示了广泛的海洋条件梯度；包含了过去两千年未受干扰的分层沉积记录；并有完善的模型。加州当前生态系统(CCE)LTER计划解决了两个关键问题：沿海远洋生态系统中导致不同生态系统状态的机制是什么？不断变化的海洋气候、群落结构和生态系统动态之间的相互作用是什么？该计划将开发一个新的量化基础，用于预测气候扰动对管理关键海洋生物资源的影响，包括大量鱼类、无脊椎动物、海洋哺乳动物和海鸟。研究区域还影响二氧化碳交换和碳固存，以及人类娱乐、航行和大量美国居民的生计。该地点包括一个国家海洋保护区，是CCS大多数上层鱼类生物量的主要产卵栖息地。这项研究将涉及对研究生和本科生的广泛培训，并将创造教师机会。将与斯克里普斯的桦树水族馆合作，扩大公共方案和外联工作，以提高公众对气候对沿海中上层群落影响的认识和了解，将公众和公众联系起来。第二阶段的CCE支持导致了广泛的新发现：关于生态系统突然变化的新的无效假设，对海洋鱼类产卵的理解，硅铁交互作用和中上层鱼类在调节碳输出中的新作用，上升流水源水域营养物质化学计量的长期变化，浮游生物生产的涡流介导的转变，以及中上层鱼类与海洋脱氧有关的变化。CCE对中尺度锋面系统的研究发现，海洋锋面对从细菌到海洋鱼类等整个食物链的生物都有显着的影响。基于滑翔机的研究表明，在锋面不连续处浮游植物和浮游动物生物量增加，卫星研究表明，在CCE区域，这种锋面特征正在增加。通过外联活动接触到了数千人。该奖项建立在研究人员之前对生态系统状态突然变化背后的机制的分析基础上，有三个新的计划要素：(1)作为长期生态系统变化调节器的跨岸输送的深入分析；(2)对厄尔尼诺-南方涛动的生物影响的定量预测的发展；以及(3)利用分子方法表征生态系统扰动的能力的扩展。将继续对东北太平洋的五个核心LTER变量及其对长期海洋变化(变暖、密度层结增加、脱氧和酸化)的反应进行多尺度测量。CCE-LTER研究在理解生态状态变化和发展预测主要上升流生态系统未来生态状态变化的量化框架方面取得了很好的进展。在这个新的奖项中，研究人员将进行密集的船上拉格朗日过程研究，以测试跨岸运输在将营养物质、其他生物化合物和生物输出到近海区域中所起的作用，从而改变种群动态和生物地球化学输出。将使用自主测量和综合建模来评估跨岸运输的气候敏感性。与生态系统转变有关的其他机制(层化的原地变化、沿岸平流、自上而下的捕食)将分别通过实地研究、结合建模的现场和遥感测量以及生物能量模型进行分析。合作研究将开发一个新的框架，用于预测ENSO对美国西海岸海洋上层生态系统的影响。分子方法将被用来描述微生物多样性和相关浮游生物相互作用的趋势。

Upwelling regions are some of the most productive ocean ecosystems. The study region of the California Current Ecosystem (CCE) LTER is the southern sector of the California Current System (CCS), a major upwelling biome where the 67-year California Cooperative Fisheries Investigations (CalCOFI) program provides essential information characterizing both natural climate variability and progressive changes. The CCE site spans a biogeographic boundary region, hence is an early sentinel of climate change; shows low frequency variations that are correlated with much of the North Pacific; is the preferred spawning site for most of the epipelagic fish biomass in the CCS; exhibits a broad gradient of ocean conditions over a short geographic distance; encompasses an undisturbed, layered sedimentary record of the past two millennia; and has well-developed models. The California Current Ecosystem (CCE) LTER program addresses two over-arching questions: What are the mechanisms leading to different ecosystem states in a coastal pelagic ecosystem? What is the interplay between changing ocean climate, community structure, and ecosystem dynamics? This program will develop a new quantitative basis for forecasting the effects of climate perturbations on the management of key living marine resources, including numerous fishes, invertebrates, marine mammals, and seabirds. The study region also affects CO2 exchange and carbon sequestration, as well as human recreation, navigation, and the livelihoods of large numbers of U.S. residents. The site encompasses a National Marine Sanctuary and constitutes major spawning habitat for most of the epipelagic fish biomass in the CCS. This research will involve extensive training of graduate students, undergraduate REU's, and will create teacher opportunities. Public programs and outreach efforts will be expanded in collaboration with the Birch Aquarium at Scripps, to increase public awareness and understanding of climate effects on coastal pelagic communities, to connect the publicPhase II support of CCE led to extensive new findings: a new null hypothesis for abrupt ecosystem shifts, understanding of phenological changes in marine fish spawning, new roles for both Si- Fe interactions and mesopelagic fishes in mediating Carbon export, long-term changes in nutrient stoichiometry in upwelling source waters, eddy-mediated transformations of plankton production, and alterations of mesopelagic fishes in relation to ocean de-oxygenation. CCE studies of mesoscale frontal systems found marked effects of ocean fronts on organisms across the food web ranging from bacteria to marine fishes. Glider-based studies showed elevated phytoplankton and zooplankton biomass at frontal discontinuities and satellite studies showed that such frontal features are increasing in the CCE region. Several thousand people were reached through outreach activities. This award builds on the investigator's previous analyses of the mechanisms underlying abrupt changes in ecosystem state with three new program elements: (1) intensive analysis of cross-shore transport as a modulator of long-term ecosystem variation; (2) development of quantitative forecasts of the biotic effects of El Niño-Southern Oscillation; and (3) expansion of the ability to characterize ecosystem perturbations using molecular approaches. Multi-scale measurements of the five core LTER variables and their responses to secular ocean changes (warming, increased density stratification, de-oxygenation, and acidification) in the NE Pacific will be sustained. CCE-LTER studies are making excellent progress toward understanding ecological state changes and the development of a quantitative framework for forecasting future changes in ecosystem states in a major upwelling ecosystem. In this new award the investigators will conduct intensive shipboard Lagrangian process studies to test the role of cross-shore transport in exporting nutrients, other biogenic compounds, and organisms into the offshore zone, thereby modifying population dynamics and biogeochemical export. Climate sensitivity of cross-shore transport will be assessed using autonomous measurements and integrative modeling. Other mechanisms related to ecosystem transitions (in situ changes in stratification, alongshore advection, top down predation) will be analyzed, respectively, by field studies employing a space-for-time exchange, in situ and remote sensing measurements combined with modeling, and bioenergetic modeling. Collaborative studies will develop a new framework for forecasting ENSO effects on marine pelagic ecosystems along the U.S. west coast. Molecular approaches will be used to characterize trends in microbial diversity and associated plankton interactomes.