Collaborative Research: Microbial influences on Alexandrium populations

合作研究：微生物对亚历山大藻种群的影响

• 批准号: 1128039
• 负责人: Linda Amaral Zettler
• 金额: $ 25.5万
• 依托单位: Marine Biological Laboratory
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1128039&HistoricalAwards=false
• 关键词: Collaborative; Research; Microbial; influences; Alexandrium

The harmful algal bloom (HAB) syndrome known as Paralytic Shellfish Poisoning (PSP) is a significant and growing problem worldwide, with negative and sometimes devastating economic and human health impacts. Dinoflagellates within the genus Alexandrium are responsible for many of these PSP outbreaks. In the northeastern US and Canada, Alexandrium blooms occur in two types of habitats -- one that is large and widespread, covering vast expanses of open coastal waters and another that is small and localized, such as within salt ponds or kettle holes on Cape Cod. Blooms in these latter systems exhibit strong "point source" characteristics in which localized cyst germination inoculates the overlying waters, leading to bloom development and eventual deposition of new cysts at that location, and thus to recurrent, self-seeding blooms. Due to their small geographic scale and limited connectivity with coastal populations, Cape Cod salt ponds represent a unique natural laboratory for the investigation of many important aspects of Alexandrium fundyense autoecology that are difficult to study in open coastal waters, larger estuarine systems, or even in mesocosms. In this project, researchers at the Woods Hole Oceanographic Institution and the Marine Biological Laboratory will conduct a coordinated field and laboratory study of population and genetic dynamics of A. fundyense in two Cape Cod salt ponds, coupled with an investigation of host-parasite interactions, grazing losses, and bacterial associated dynamics, examined within the context of local hydrodynamics. The project hypothesis is that abrupt, short-term changes in Alexandrium population dynamics and structure are associated with identifiable changes in abundance and community composition of bacteria, parasites, and/or grazers. A comparative approach will be used to reveal processes that are common to both sites, but that occur at different times. Specific objectives are to: 1) Characterize Alexandrium population abundance and structure in two isolated salt ponds, as well as the dynamics and impacts of losses due to parasitism and grazing; 2) Generate and analyze comparative high resolution microbial community structure data before, during, and after Alexandrium blooms; and 3) Obtain high-resolution hydrodynamic data within the study area and use that information to interpret microbial network data and Alexandrium population structure in an environmental context. Having worked together in the past as PIs in the Woods Hole Center for Ocean and Human Health (WHCOHH), the investigators will share and synthesize data to identify the major influences on A. fundyense populations, and use these insights to inform an existing physical/biological model of A. fundyense bloom dynamics within the NMS. These will also help us to refine our models of the offshore blooms for the Gulf of Maine, for which forcing functions and loss terms are difficult to isolate and quantify. Broader Impacts. The study site is a multi-user, high-value resource that includes parts of the Cape Cod National Seashore (CACO). PSP has become a major concern to residents and commercial shell fishermen due to the temporal and spatial increase in harvesting closures over the last two decades. The data and analyses produced will be of value in policy decisions about many issues in the system, including sewage treatment, groundwater quality, aquaculture, shellfish propagation, and harvesting closure policies. This project also lends itself to undergraduate, graduate, and postdoctoral training.

被称为麻痹性贝类中毒（PSP）的有害藻华（HAB）综合征是全球范围内的一个重要且日益严重的问题，具有负面的，有时是毁灭性的经济和人类健康影响。 亚历山大藻属内的甲藻是许多PSP爆发的原因。 在美国东北部和加拿大，亚历山大藻水华发生在两种类型的栖息地-一种是大而广泛，覆盖广阔的开放沿海沃茨，另一种是小而局部的，如在盐池或科德角的水壶洞。 在这些后者系统中的水华表现出很强的“点源”特性，其中本地化的孢囊萌发接种上覆的沃茨，导致水华的发展和最终沉积的新的孢囊在该位置，从而经常性的，自播种的水华。 由于其小的地理规模和有限的连接与沿海人口，科德角盐池代表了一个独特的自然实验室的调查Alexandrum fundyense自我生态学的许多重要方面，很难在开放的沿海沃茨，较大的河口系统，甚至在中生态系统的研究。 在这个项目中，伍兹霍尔海洋研究所和海洋生物实验室的研究人员将对A. fundyense在两个科德角盐池，再加上宿主-寄生虫的相互作用，放牧损失，和细菌相关的动态，在当地的流体动力学的背景下检查的调查。 该项目的假设是，亚历山大藻种群动态和结构的突然，短期变化与细菌，寄生虫和/或食草动物的丰度和群落组成的可识别变化有关。 比较的方法将被用来揭示过程是共同的两个网站，但发生在不同的时间。 具体目标是：1）表征两个隔离的盐池中的亚历山大藻种群丰度和结构，以及由于寄生和放牧造成的损失的动态和影响; 2）在亚历山大藻开花之前、期间和之后生成并分析比较高分辨率的微生物群落结构数据;（3）获得高-解析研究区域内的水动力学数据，并使用该信息来解释微生物网络数据和亚历山大藻种群结构的环境背景下。 在过去作为伍兹霍尔海洋与人类健康中心（WHCOHH）的PI一起工作，研究人员将分享和综合数据，以确定对A的主要影响。 fundyense种群，并使用这些见解告知现有的物理/生物模型的A。 fundyense水华动态在NMS内。 这些也将帮助我们完善我们的模式的近海水华的缅因州，迫使功能和损失条款是很难隔离和量化。 更广泛的影响。 该研究地点是一个多用户，高价值的资源，包括科德角国家海岸（CACO）的一部分。 由于过去二十年中捕捞关闭的时间和空间增加，PSP已成为居民和商业贝类渔民的主要担忧。 所产生的数据和分析将对有关该系统许多问题的决策具有价值，包括污水处理、地下水质量、水产养殖、贝类繁殖和捕捞关闭政策。 该项目也适用于本科生，研究生和博士后培训。