Biological and Physical Controls of Alexandrium Bloom Initiation and Termination

亚历山大藻花盛开和终止的生物和物理控制

• 批准号: 8413150
• 负责人: Donald M Anderson
• 金额: $ 13.44万
• 依托单位: WOODS HOLE OCEANOGRAPHIC INSTITUTION
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8413150
• 关键词: Address; Area; Biological; Biological Assay; Biological Markers; Biological Models; Cells; Cods; Cyst; Data; Deposition; Detection; Development; Dinophyceae; Disease Outbreaks; Environmental Risk Factor; Epigenetic Process; Event; Germ Cells; Germination; Goals; Growth; Habitats; Health Benefit; Health Professional; Human; Image; In Situ; Industry; Infection; Instruction; Investigation; Laboratories; Laboratory Study; Lead; Life; Life Cycle Stages; Light; Link; Location; Maine; Measures; Modeling; Molecular; Nutrient; Optics; Paralysed; Parasites; Phase; Physiological; Physiology; Plankton; Poisoning; Population; Population Dynamics; Process; Process Measure; Public Health; Recurrence; Reproduction; Research; Research Support; Resolution; Resources; Risk; Sampling; Seafood; Shellfish; Site; Sodium Chloride; Staging; Syndrome; System; Techniques; Temperature; Testing; Time; Toxin; Water; Work; coastal water; comparative; field study; harmful algal blooms; improved; innovation; parasitism; programs; research study; social; zygote

This research will identify and model the biological and physical mechanisms regulating two key processes in the blooms of Alexandrium dinoflagellates responsible for paralytic shellfish poisoning (PSP): bloom initiation and termination. A key feature of the project is that it will be conducted in the Nauset Marsh System (NMS), a shallow estuary that has recurrent A. fundyense blooms in its three terminal kettie ponds, with blooms being unequivocally tied to cyst seedbeds in those embayments. The NMS represents a natural "mesocosm" where these processes can be studied in a manner not possible in open coastal waters. The NMS also represents a major habitat for toxic Alexandrium species in the US and worldwide. Aim 1 comprises field and lab experiments on bloom initiation. Excystment experiments will determine whether internal or external factors regulate germination seasonality, and other studies will measure the effects of temperature, salinity, and light on germination and growth. The timing and rate of escape of germinated cells will be measured using plankton emergence traps, and high-resolution sampling will be conducted throughout bloom initiation. Aim 2 activities are focused on bloom termination. A unique submersible flow cytometer with imaging capabilities (the imaging flow cytobot, IFCB) will detect life cycle transitions in situ. Routine and adaptive field sampling (triggered by IFCB data) will document factors associated with life cycle transitions, and sediment traps will assess the timing and rate of cyst deposition. Complimentary efforts will utilize a bentop multi-daser IFCB to confirm the presence of sexual forms in field samples, an assessment of the linkage between A. fundyense encystment and parasite infection, and the development of biomarker assays for detection of gametes and planozygotes that will be applied in sampling for these stages in situ. In Aim 3, an innovative Lagrangian approach will model Alexandrium population dynamics within the NMS, including life cycle transitions. The model will be formulated and calibrated against blooms in the NMS, but is broadly transferable to HAB models in estuarine or coastal settings, including Project 2 in this program.

这项研究将确定并模拟调节负责瘫痪贝类中毒（PSP）的亚历山大鞭毛鞭毛的盛开的两个关键过程的生物学和物理机制：开花和终止。该项目的一个关键特征是它将在Nauset Marsh System（NMS）中进行，这是一个浅层河口，在其三个末端的Kettie Ponds中经常出现的A. Fundyense盛开，鲜花无疑将其与这些胚芽中的囊泡床绑在一起。 NMS代表了一种天然的“中库”，在该过程中可以在开放的沿海水域中以某种方式研究这些过程。 NMS还代表了美国和全球有毒亚历山大种类的主要栖息地。 AIM 1包括有关Bloom启动的现场和实验实验。 ExcySment实验将确定内部或外部因素是否调节发芽季节性，其他研究将衡量温度，盐度以及光对发芽和生长的影响。将使用浮游生物陷阱来测量发芽细胞的时机和逃逸速率，并将在整个Bloom启动过程中进行高分辨率采样。 AIM 2活动集中在开花终止上。具有成像能力（成像流式细胞库，IFCB）的独特潜水流式细胞仪将原位检测生命周期过渡。常规和自适应场采样（由IFCB数据触发）将记录与生命周期过渡相关的因素，而沉积物陷阱将评估囊肿沉积的时间和速率。免费努力将利用Bentop Multi-Daser IFCB来确认在现场样本中存在性形式，评估Fundyense A. fundyense Encystment和寄生虫感染之间的联系，以及开发生物标志物测定法以检测配子和Planozygotes，这些测定将用于这些阶段，以在这些阶段中应用。在AIM 3中，创新的Lagrangian方法将模拟NMS内的Alexandrium人口动态，包括生命周期过渡。该模型将针对NMS中的开花进行制定和校准，但可以广泛地转移到河口或沿海环境中的HAB模型，包括该计划中的项目2。