Estuary plumes as drivers of inner continental shelf benthic community structure and function

河口羽流作为内陆架底栖群落结构和功能的驱动因素

基本信息

批准号：
2048902
负责人：
Ryan Woodland
金额：
$ 94.66万
依托单位：
University of Maryland Center for Environmental Sciences
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-03-01 至 2025-02-28
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2048902&HistoricalAwards=false
关键词：
Estuary plumes drivers inner continental

项目摘要

In the coastal ocean, nutrient-rich river or estuary waters mix with less-enriched marine waters creating plumes, regions that are very productive and important for fisheries and nutrient cycling. The location and size of these estuary plumes are highly dynamic because of seasonal changes in weather, winds, and ocean currents. The amount of nutrients carried by plumes – and thus their impact on the coastal ocean – also changes seasonally. This project is studying how the plume of the nation’s largest estuary, the Chesapeake Bay, changes over the course of the year and what those changes mean for food webs and nutrient cycles in the coastal Atlantic Ocean. A model of water movements is being developed to predict how river flow, winds, and currents converge to cause seasonal changes in plume size, location, and composition. Research cruises spanning the area of the plume within the coastal ocean are collecting material within the plume as well as the animals living under and on top of the sediments. In parallel, experiments conducted on the ship are investigating how the animals and the chemical reactions in the sediment are affected by materials within the plume. By combining this modelling, measurements of bottom animal biomass and biodiversity, and nutrient experiments, this project is determining how estuarine plumes drive coastal food webs and productivity. Broader impacts include benefits to natural resource management through a better understanding of the linkages between plume dynamics, food webs and fisheries. Doctoral students, a postdoctoral scholar and undergraduate students are being trained in modeling, experimental and field research methods. Increasing diversity in STEM fields is occurring through a partnership with a community college (College of Southern Maryland) to recruit summer interns for research experiences. Outreach activities include the development of age-appropriate educational materials for the public and the use of these materials at ‘in person’ or virtual outreach events.The overarching goal is to determine how the magnitude and reactivity of organic matter inputs and environmental conditions associated with spatially and temporally dynamic estuarine plumes affect inner continental shelf benthic communities. The project is analyzing the role of organic matter deposition, both labile and refractory, as a driver of benthic community structure and sediment-water biogeochemical flux rates. An integrative approach that combines hydrodynamic modelling, field observations and shipboard experiments is linking benthic responses to seasonal changes in plume characteristics. Specifically, a calibrated hydrodynamic model is being used to establish the history of plume-driven conditions and to quantify particle transport and deposition on the inner shelf. A survey of water-column conditions, organic matter pools, and benthic and epibenthic community composition at a fixed station grid are generating empirical measurements of benthic taxonomic and functional composition, biodiversity, and biomass. These measurements are being used to estimate secondary production and assess how it varies seasonally. Sediment-water nutrient fluxes and organic matter-specific nutrient assimilation rates (labile, refractory) by benthos are being quantified using experimental core incubations. Hydrodynamic plume reconstructions are coupled with observational and experimental data to test hypotheses regarding the stimulation of benthic biomass, biodiversity, and secondary production by plume particulate organic matter inputs both seasonally and spatially. Statistical models that account for feeding mode, past exposure to plume influence, lability of deposited organic matter, and physical forces (e.g., temperature, salinity, bed stress) are being developed to predict benthic responses to simulated plume conditions and, potentially, inform understanding of plume dynamics more broadly.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.

在沿海海洋中，营养丰富的河流或河口水域与营养较少的海水混合，形成羽流，这些区域对渔业和养分循环非常重要且生产力很高。由于季节变化，这些河口羽流的位置和大小高度动态。天气、风和洋流的影响——以及它们对沿海海洋的影响——也随着季节的变化而变化。切萨皮克湾一年中的变化以及这些变化对大西洋沿岸的食物网和营养循环意味着什么，我们正在开发一个水运动模型来预测河流、风和水流如何汇聚导致季节性。跨越沿海海洋羽流区域的研究巡航正在收集羽流内的物质以及生活在沉积物下方和顶部的动物，同时进行实验。该船正在调查如何通过结合该模型、底部动物生物量和生物多样性的测量以及营养物实验，该项目正在确定河口羽流如何驱动沿海食物网和生产力。通过更好地了解羽流动力学、食物网和渔业之间的联系，对自然资源管理有利博士生、博士后学者和本科生正在接受建模、实验和实地研究方法的培训，增加 STEM 领域的多样性。正在通过与社区学院（南马里兰学院）合作招募暑期实习生来获得研究经验，外展活动包括为公众开发适合年龄的教育材料以及“面对面”或虚拟使用这些材料。总体目标是确定有机物输入的大小和反应性以及与时空动态河口羽流相关的环境条件如何影响内陆架底栖群落。该项目正在分析有机物沉积的作用，既不稳定又难控制，作为底栖群落结构和沉积物-水生物地球化学通量速率的驱动因素，一种结合了水动力模型、现场观测和船上实验的综合方法正在将底栖响应与羽流特征的季节变化联系起来。用于建立羽流驱动条件的历史，并量化内架上的颗粒迁移和沉积。对水柱条件、有机物池以及底栖和沉积物的调查。固定站网格的表层群落组成正在生成底栖分类和功能组成、生物多样性和生物量的经验测量值，这些测量值用于估计二次生产并评估其季节性变化。底栖生物的营养同化率（不稳定的、难熔的）正在通过实验核心孵化进行量化，并结合观察和实验数据来测试有关刺激的假设。底栖生物量、生物多样性和羽流颗粒有机物输入的季节性和空间性统计模型，考虑了进食模式、过去受到羽流影响的暴露、沉积有机物的不稳定性和物理力（例如温度、盐度、床层）。正在开发预测海底对模拟羽流条件的响应，并有可能更广泛地了解羽流动力学。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。