Hydrodynamic forcing of Alexandrium population biology

亚历山大藻种群生物学的水动力强迫

• 批准号: 6747096
• 负责人: DENNIS J MCGILLICUDDY
• 金额: $ 5.06万
• 依托单位: WOODS HOLE OCEANOGRAPHIC INSTITUTION
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6747096
• 关键词: Dinoflagellates; Protista; United States; algae; aquatic organism; biological models; climate; ecology; field study; genotype; geographic site; marine biology; microorganism population study; molecular dynamics; physical model; saltwater environment; seafood poisoning; statistics /biometry; water flow; water microbiology; water quality

Blooms of the toxic dinoflagellate Alexandrium fundyense are annually recurrent phenomena in the Gulf of Maine during the spring and summer months. Toxins produced by A. fundyense accumulate in the tissues of filter-feeding shellfish such as mussels and clams. Human ingestion of these contaminated shellfish can lead to Paralytic Shellfsh Poisoning (PSP), a potentially fatal illness. Understanding the factors that determine the distribution and abundance of A. fundyense is therefore of considerable economic and public health interest. Existing data and models demonstrate strong interconnections between A. fundyense populations and the Gulf of Maine coastal current system. Indeed, coupled physical-biological models of population dynamics and hydrodynamic transport are able to simulate some of the general features of the observed A. fundyense distribution. However, such models are sensitive to the choices of the input parameters (e.g. growth rate, swimming speed, germination rate, etc). Curiously, the ability of the models to match the observations occurs in a range of this parameter space that is relatively narrow with respect to the envelope of reasonable values defined by laboratory and field measurements. One possible explanation for this apparent inconsistency is genetic heterogeneity in the natural populations. We hypothesize that the aggregate distribution of A. fundyense is composed of a mosaic of genetically distinct subpopulations, each with different physiological and/or behavioral responses to environmental conditions. The goal of this project is to understand the hydrodynamic and biological controls on these populations, their toxin production, and how these factors ultimately determine fluctuations in shellfish toxicity.

在春季和夏季，缅因州湾的有毒鞭毛鞭毛藻植物的绽放是每年反复发生的现象。 A. fundyense产生的毒素积聚在过滤器喂养贝类的组织中，例如贻贝和蛤。这些受污染的贝类的人类摄入可能导致瘫痪的壳虫中毒（PSP），这是一种潜在的致命疾病。因此，了解确定A. fundyense分布和丰富性的因素具有相当大的经济和公共卫生利益。现有的数据和模型表明，A. fundyense种群与缅因州沿海电流系统之间的牢固互连。确实，人口的物理生物学模型耦合 动力学和流体动力传输能够模拟观察到的fundyense分布的某些一般特征。但是，此类模型对输入参数的选择敏感（例如增长率，游泳速度，发芽率等）。奇怪的是，模型与观测值匹配的能力发生在此参数空间的范围内，该范围相对于由实验室和现场测量所定义的合理值的包络相对较窄。这种明显不一致的一种可能的解释是自然种群中的遗传异质性。我们假设A. fundyense的骨料分布由遗传上不同亚群的镶嵌物组成，每个亚群具有不同的生理和/或行为对环境条件的反应。该项目的目的是了解这些人群的流体动力和生物控制，它们的毒素产生以及这些因素最终如何确定贝类毒性的波动。