Collaborative Research: Regulation of plankton and nutrient dynamics by hydrodynamics and profundal filter feeders

合作研究：通过流体动力学和深层滤食性动物调节浮游生物和营养动态

• 批准号: 1658390
• 负责人: Harvey Bootsma
• 金额: $ 60.84万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-05-01 至 2022-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1658390&HistoricalAwards=false
• 关键词: Collaborative; Research; Regulation; plankton; nutrient

Benthic filter feeders such as clams and mussels influence plankton and nutrient dynamics in shallow marine and freshwater systems, but their role is generally considered to be minor in large, deep systems. However, recent evidence indicates that profundal quagga mussels (Dreissena rostriformis bugensis) have dramatically altered energy flow and nutrient cycling in the Laurentian Great Lakes and other large, deep aquatic systems, with negative consequences for many other components of the food web. Previously, management strategies for these lakes relied on numerical models that predicted the lake's response to phosphorus loading. The proliferation of benthic filter feeders in the lakes appears to have fundamentally altered the dynamics of phosphorus cycling and energy flow, so that these models are no longer valid. This project measures energy flow and nutrient cycling processes in Lake Michigan, with a focus on the role of quagga mussels in these processes, and uses these measurements to develop numerical models to guide management decisions with regard to nutrient loading and fish stocking. In addition to supporting the education of three Ph.D. students and providing research training for undergraduate students, the project promotes education of future aquatic scientists by hosting a workshop on interdisciplinary research and modeling for students and making workshop lectures available through an open-access project website.This collaborative biophysical project is structured around two primary questions: 1) What role do profundal dreissenid mussels play in large lake carbon and nutrient cycles? 2) How are mussel grazing and the fate of nutrients recycled by mussels modulated by hydrodynamics at scales ranging from mm (benthic boundary layer) to meters (entire water column)? The investigators hypothesize that the apparent enhanced particle deliver rate to the lake bottom results from high filtration capacity combined with vertical mixing processes that advect phytoplankton from the euphotic zone to the near bottom layer. However, the role of hydrodynamics is unclear, because these processes are poorly characterized both within the hypolimnion as a whole and within the near-bottom layer. In addition, the implications for phytoplankton and nutrient dynamics are unclear, as mussels are both grazers and nutrient recyclers. State-of-the-art instruments and analytical tools, including particle image velocimetry, acoustic Doppler current profilers, and nutrient micro-profilers, are being deployed in Lake Michigan to quantify these critical dynamic processes, including boundary layer turbulence, mussel grazing, excretion and egestion, and benthic fluxes of carbon and phosphorus. Resulting data are used to calibrate a 3D hydrodynamic-biogeochemical model, which is used to address the overarching question of how plankton and nutrient dynamics in large, deep lakes with abundant profundal filter feeders differ from the conventional paradigm described by previous models. The project also provides insight into bottom boundary layer physics, with applicability to other large lakes, atidal coastal seas, and the deep ocean.

蛤和贻贝等底栖滤食性动物影响着浅海和淡水系统中的浮游生物和营养动态，但一般认为它们在大型深海系统中的作用很小。 然而，最近的证据表明，深海斑驴贻贝（Dreissena rostriformis bugensis）已显着改变能量流和营养循环在劳伦特五大湖和其他大型，深水生系统，与食物网的许多其他组件的负面影响。 以前，这些湖泊的管理策略依赖于预测湖泊对磷负荷的响应的数值模型。 在湖泊中的底栖滤食性动物的扩散似乎已经从根本上改变了磷循环和能量流的动态，使这些模型不再有效。 该项目测量密歇根湖的能量流和营养循环过程，重点是斑驴贻贝在这些过程中的作用，并使用这些测量开发数值模型，以指导管理决策方面的营养负荷和鱼类放养。 除了支持三个博士的教育。该项目通过为学生举办跨学科研究和建模研讨会，并通过开放获取的项目网站提供研讨会讲座，促进未来水生科学家的教育。这个合作生物物理项目围绕两个主要问题展开：1）深水德雷塞尼贻贝在大型湖泊碳和营养循环中发挥什么作用？2)贻贝放牧和贻贝回收的营养物质的命运是如何在从毫米（底栖边界层）到米（整个水柱）的尺度上受到流体动力学的调制的？研究人员假设，明显增强的颗粒输送速率湖底的结果，从高过滤能力与垂直混合过程相结合，平流浮游植物从透光层到近底层。然而，流体动力学的作用尚不清楚，因为这些过程在整个静水层和近底层内的特征都很差。此外，对浮游植物和营养动态的影响尚不清楚，因为贻贝既是食草动物又是营养循环者。目前正在密歇根湖部署最先进的仪器和分析工具，包括粒子图像测速仪、声学多普勒海流剖面仪和营养物微剖面仪，以量化这些关键的动态过程，包括边界层湍流、贻贝放牧、排泄和排泄以及底栖碳和磷通量。由此产生的数据被用来校准的三维水动力-地球化学模型，这是用来解决的首要问题，如何在大型，深湖丰富的深海滤食动物的浮游生物和营养动态不同于传统的模式所描述的以前的模型。该项目还提供了对底边界层物理学的深入了解，适用于其他大型湖泊，潮汐沿海和深海。

项目成果

Regulation of plankton and nutrient dynamics by profundal quagga mussels in Lake Michigan: a one-dimensional model

• DOI: 10.1007/s10750-018-3547-6
• 发表时间: 2018-02
• 期刊: Hydrobiologia
• 影响因子: 2.6
• 作者: Chunqi Shen;Q. Liao;H. Bootsma;C. Troy;D. Cannon

Modelling the transport of sloughed cladophora in the nearshore zone of Lake Michigan

模拟密歇根湖近岸区域脱落的刚毛虫的运输

• DOI: 10.1016/j.jenvman.2022.116203
• 发表时间: 2022
• 期刊: Journal of Environmental Management
• 影响因子: 8.7
• 作者: Shen, Chunqi;Liao, Qian;Bootsma, Harvey A.;Lafrancois, Brenda Moraska
• 通讯作者: Lafrancois, Brenda Moraska

Modelling the influence of invasive mussels on phosphorus cycling in Lake Michigan

模拟入侵贻贝对密歇根湖磷循环的影响

• DOI: 10.1016/j.ecolmodel.2019.108920
• 发表时间: 2020
• 期刊: Ecological Modelling
• 影响因子: 3.1
• 作者: Shen, Chunqi;Liao, Qian;Bootsma, Harvey A.
• 通讯作者: Bootsma, Harvey A.

Characterizing the Seasonal Variability of Hypolimnetic Mixing in a Large, Deep Lake

描述大型深湖中低记忆混合的季节变化

• DOI: 10.1029/2021jc017533
• 发表时间: 2021
• 期刊: Journal of Geophysical Research: Oceans
• 作者: Cannon, David James;Troy, Cary;Bootsma, Harvey;Liao, Qian;MacLellan‐Hurd, Rae‐Ann
• 通讯作者: MacLellan‐Hurd, Rae‐Ann