Consequences of hypoxia on food web linkages in a pelagic marine ecosystem

低溶解氧（缺氧）是海洋生态系统中最明显、最普遍和最重要的干扰之一。然而，我们对缺氧对远洋食物网的生态影响的理解是不完整的，因为我们对有机体对缺氧的反应如何影响关键生态系统过程的认识有限。在远洋食物网中，中浮游动物及其捕食者的分布变化可能影响捕食者-被捕食者的重叠，并决定食物网的能量流动。同样，缺氧可能导致浮游动物群落组成向阻碍能量流向浮游鱼类的物种转变。然而，物种和群落的补偿反应可能会抵消这些影响，维持营养耦合和维持上层营养物种的生产力。pi计划回答“缺氧是否会影响中浮游动物到远洋鱼类的能量流动？”他们用一个嵌套的假设框架来解决这个问题，这个框架考虑了两组过程，它们交替地负责改变或维持远洋生态系统的能量流。他们将在华盛顿州胡德运河进行研究。与大多数受缺氧影响的河口不同，胡德运河的缺氧区域离不受影响的地点很近。这使得进行比较研究在逻辑上更容易，并且在比较相隔很远的地区时减少了潜在混淆因素的数量。更广泛的影响提高对缺氧如何影响海洋生态系统的理解将有利于基于生态系统的管理（EBM）在沿海和河口生态系统中的实际应用。实证医学的有效应用要求充分了解人类活动的影响，并可以使用指标跟踪生态影响。这个项目将有助于满足这两个需求。pi将与联邦、州、部落和县的生物学家分享他们在地方和国家层面的发现。为了增加对代表性不足的群体的科学接触，ppi还将通过夏季实习为美洲原住民青年提供参与实地收集和实验室处理的机会。ppi将与nsf资助的太平洋西北路易斯斯托克斯少数民族参与联盟和胡德运河地区的部落合作，招募和指导学生从事海洋科学方面的潜在职业。该项目将资助几名本科生、两名博士生、一名博士后和两名早期职业科学家。

Intellectual MeritLow dissolved oxygen (hypoxia) is one of the most pronounced, pervasive, and significant disturbances in marine ecosystems. Yet, our understanding of the ecological impacts of hypoxia on pelagic food webs is incomplete because of our limited knowledge of how organism responses to hypoxia affect critical ecosystem processes. In pelagic food webs, distribution shifts of mesozooplankton and their predators may affect predator-prey overlap and dictate energy flow up food webs. Similarly, hypoxia may induce shifts in zooplankton community composition towards species that impede energy flow to planktivorous fish. However, compensatory responses by species and communities might negate these effects, maintaining trophic coupling and sustaining productivity of upper trophic level species. The PIs propose to answer the question "Does hypoxia affect energy flow from mesozooplankton to pelagic fish?" They approach this question with a nested framework of hypotheses that considers two sets of processes alternatively responsible for either changes or maintenance of pelagic ecosystem energy flows. They will conduct their study in the Hood Canal, WA. Unlike most hypoxia-impacted estuaries, hypoxic regions of Hood Canal are in close proximity to sites that are not affected. This makes it logistically easier to conduct a comparative study and reduces the number of potential confounding factors when comparing areas that are far apart.Broader ImpactsImproved understanding of how hypoxia impacts marine ecosystems will benefit the practical application of ecosystem-based management (EBM) in coastal and estuarine ecosystems. Effective application of EBM requires that the impacts of human activities are well understood and that ecological effects can be tracked using indicators. This project will contribute to both of these needs. The PIs will share their findings on local and national levels with Federal, State, Tribal, and County biologists. To increase exposure of science to underrepresented groups, the PIs also will provide Native American youth with opportunities to participate in field collections and laboratory processing through summer internships. The PIs will collaborate with the NSF-funded Pacific Northwest Louis Stokes Alliance for Minority Participation and tribes from the Hood Canal region to recruit and mentor students for potential careers in marine science. This project will support several undergraduate researchers, two Ph.D. students, a post-doc, and two early-career scientists.