EU-US ECOHAB. EC-NSF Cooperative Activity in Environmental Research: In Situ Holographic Measurements of Particle Distributions and Small Scale Turbulence in Thin Layers

欧盟-美国ECOHAB。

• 批准号: 0402792
• 负责人: Joseph Katz
• 金额: $ 73万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402792&HistoricalAwards=false
• 关键词: EU; US; ECOHAB.; EC; NSF

This project was submitted under the EU-US Cooperative Activity on the Ecology and Oceanography of Harmful Algae. The U.S. PIs will join colleagues from France, Ireland, Spain and UK to study the physics and biology of thin layers with concentrated Harmful Algal Bloom (HAB). Serious problems in Europe are caused by contamination of farmed shellfish with Diarrheic Shellfish Poisoning (DSP) toxins produced by the dinoflagellate genus Dinophysis. The existence of thin layers with high Dinophysis concentration has come to light recently, but the information is sporadic because the layers can be present at any depth, and due to sampling difficulties with standard instruments. In the case of Dinophysis, the concentration does not depend solely on nutrition, but also on interactions between physics, life cycle and behavior. This study will determine the hydrodynamic (e.g. local flow structure, turbulence, stratification, small gyres and pycnoclines), biological (e.g. growth, nutrition and mortality) and chemical environment leading to the build up, maintenance and population dynamics of Dinophysis in thin layers. The field tests will take place under a variety of hydrodynamic regimes in the Rias of Galicia (NWSpain), the estuarine plume zones of the Atlantic coast of France, and in the bays of southwestern Ireland. All are shellfish production areas with history of harvest closures due to contamination with DSP toxins. The Johns Hopkins group will focus on small-scale biophysical and particle-particle interactions. By deploying a submersible holocamera, augmented with a digital holographic cinematography, they will observe and measure processes and interactions occurring at the critical scales of 10 mm to 10 cm. Automated data analysis tools will enable the investigators to process a large database under various conditions that will be used for parameterizing the behavior of Dinophysis. The results will include: i. The spatial and size distributions of different classes of particles. Particles larger than 10 mm are detected, and shapes can be defined in particles larger than 30 mm. ii. The nearest neighbor distance (NNS) within the same species, and between species, including predators and prey; iii. The instantaneous 3-D velocity distributions within the sample volume, which is used for calculating the local velocity, strain rate, vorticity, dissipation rate and turbulence intensity; iv. The swimming behavior (speed, trajectory, direction) of Dinophysis in its local environment; v. Direct observations on behavior, feeding and grazing of Dinophysis; vi. Conditional statistics of concentration, NNS and behavior based on local physical and biological parameters;Intellectual Merit: Progress in understanding of population dynamics of different phytoplankton species, including Dinophysis, requires detailed knowledge of their in-situ concentrations, behavior, and biophysical interactions. This project will deploy a new but proven/developed technology in the ocean in order to obtain detailed and unique insight on the interaction of dinoflagellates with their local biophysical environments. The results will illuminate processes affecting the formation and maintenance of thin layers containing Dinophysis. Broader Impacts. Socio-Economic Issues: HAB adversely affect health, tourism, fisheries and food production in the coastal ocean, causing closure of fisheries, illness and even death. This project will obtain essential information to develop such understanding of the importance of bio-physical mechanisms in the formation of some HABs. Education of future Scientists: Studies of biophysical interactions in the ocean require background in biology, fluid mechanics, and instrumentation. This project will support one such student in an interdisciplinary training program.

该项目是在欧盟-美国有害藻类生态学和海洋学合作活动下提交的。美国的pi将与来自法国、爱尔兰、西班牙和英国的同事一起研究有害藻华（HAB）集中的薄层的物理学和生物学。在欧洲，严重的问题是养殖贝类被甲藻属甲藻产生的腹泻性贝类中毒（DSP）毒素污染。最近发现了具有高恐龙浓度的薄层，但由于这些层可以存在于任何深度，并且由于标准仪器的采样困难，因此信息是零星的。就恐龙而言，浓度不仅取决于营养，还取决于物理、生命周期和行为之间的相互作用。这项研究将确定水动力（如局部流动结构、湍流、分层、小环流和斜斜）、生物（如生长、营养和死亡）和化学环境，导致薄层中恐龙的形成、维持和种群动态。现场试验将在加利西亚的里亚斯（西班牙西北部）、法国大西洋沿岸的河口羽流区和爱尔兰西南部的海湾等地的各种水动力制度下进行。这些都是贝类产区，有因DSP毒素污染而关闭捕捞的历史。约翰霍普金斯大学的研究小组将专注于小规模的生物物理和粒子间的相互作用。通过部署一个潜水全息摄像机，并辅以数字全息摄影技术，他们将观察和测量在10毫米到10厘米的临界尺度上发生的过程和相互作用。自动化数据分析工具将使研究人员能够处理各种条件下的大型数据库，这些数据库将用于参数化恐龙的行为。结果将包括：i.不同类别粒子的空间和尺寸分布。可以检测到大于10毫米的颗粒，并且可以在大于30毫米的颗粒中定义形状。同一物种内和物种间的最近邻距离（NNS），包括捕食者和被捕食者；3。样品体积内的瞬时三维速度分布，用于计算局部速度、应变率、涡量、耗散率和湍流强度；iv.恐龙在局部环境中的游动行为（速度、轨迹、方向）；5 .直接观察恐龙的行为、摄食和放牧；vi.基于局部物理和生物参数的浓度、神经网络和行为的条件统计；智力优势：在了解不同浮游植物物种（包括恐龙）的种群动态方面取得进展，需要详细了解它们的原位浓度、行为和生物物理相互作用。该项目将在海洋中部署一种经过验证的新技术，以获得鞭毛藻与当地生物物理环境相互作用的详细和独特的见解。研究结果将阐明影响含有恐龙的薄层形成和维持的过程。更广泛的影响。社会经济问题：有害藻华对沿海海洋的健康、旅游、渔业和粮食生产产生不利影响，造成渔场关闭、疾病甚至死亡。该项目将获得必要的信息，以发展对某些有害藻华形成的生物物理机制的重要性的理解。未来科学家的教育：海洋生物物理相互作用的研究需要生物学，流体力学和仪器的背景。该项目将支持一名这样的学生参加跨学科培训计划。