RUI: Harmful Ulvoid Macroalgal Blooms in Washington State

RUI：华盛顿州有害的巨藻大量繁殖

• 批准号: 0525385
• 负责人: Timothy Nelson
• 金额: $ 2.4万
• 依托单位: Seattle Pacific University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0525385&HistoricalAwards=false
• 关键词: RUI; Harmful; Ulvoid; Macroalgal; Blooms

Intellectual Merit: "Green tides " or blooms of green macroalgae occur worldwide, but are most common in temperate latitudes. These blooms are extremely productive,albeit ephemeral, communities. They are often associated with eutrophication; however, a variety of abiotic and biotic factors, including competitors, light, temperature, and nutrient levels, may limit their abundance and productivity. In temperate regions, green algal blooms have been blamed for eradicating seagrass meadows and altering faunal community structure. These effects are usually associated with shading and anoxia, but increasing evidence suggests that toxins produced by some bloom-forming macroalgae directly affect co-occurring algae and invertebrates. The causes, extents, and histories of blooms of ulvoid green algae that occur in the Pacific Northwest are not as well known as in other regions. Preliminary studies suggest that blooms have the ability to alter marine community structure and diversity. Fragmentation of eelgrass meadows by ulvoid blooms has frequently been observed, and blooms can reduce shoot density. In these waters, seagrasses are critically important as habitat and as a food source for numerous ecologically important species, including fish, shellfish,c rabs, birds and mammals. Initial evidence suggests that the mechanisms by which green algal blooms in the Pacific Northwest affect co-occurring species are varied and may include both direct and indirect effects of toxins produced by the algae. The goal of this project is to study the causes and consequences of ulvoid algal blooms in the Pacific Northwest. Environmental factors associated with bloom formation will be measured by monitoring sites where blooms typically have and have not occurred in the past. Manipulative field experiments will be used to determine the effects of light and nutrients on the growth and physiology of bloom forming algae. Field measurements will be used to measure grazing rates on algae and bioassay guided fractionation methods will be used to isolate algal toxins. Toxicological assays will be used to assess the effects of toxins on macroalgae, seagrasses, invertebrates, and fish.Broader Impacts: This research will provide a better understanding of the mechanisms that initiate the formation of blooms and contribute to their persistence. This project will examine the production of toxins, a novel mechanism for the harmful effects of ulvoid blooms. Ulvoid blooms and their deleterious effects have been described previously; however, the mechanisms for the effects of these blooms have usually been attributed to their ability to smother other plants and animals or to the harmful effects of decreased oxygen concentrations that occur as the algae decompose. Preliminary experiments suggest that direct toxicity may be important and that this effect differs between ulvoid algal species. Knowledge of the species in the blooms that are most likely to cause toxic impacts and the nature of the toxins present will aid in the development of management plans by both agencies and aquaculturists. This project will provide training for graduate students at the Shannon Point Marine Center (SPMC) and undergraduates at both Seattle Pacific University (SPU)and SPMC, as well as graduate student research assistants at SPMC and undergraduate research assistants at SPU. In addition, students participating in SPMC 's Research Experiences for Undergraduates (REU) program and Minorities in Marine Science Undergraduate Program will work on the project. Two of the study sites are of particular interest to local citizens' groups. Members of these groups will be invited to assist in the research and data from the project will be shared with these groups. To further enhance understanding of macroalgal blooms, a web site will be created with general information about algal blooms, information about this project, results, and water quality data.

知识专长：“绿色潮“或大型绿色藻类的大量繁殖在世界各地都有发生，但在温带地区最为常见。 这些花朵是非常有生产力的，虽然短暂的，社区。 它们通常与富营养化有关;然而，各种非生物和生物因素，包括竞争对手，光照，温度和营养水平，可能会限制它们的丰度和生产力。 在温带地区，绿色藻类大量繁殖被认为是导致海草草甸消失和改变动物群落结构的原因。 这些影响通常与遮荫和缺氧有关，但越来越多的证据表明，一些水华形成的大型藻类产生的毒素直接影响共生藻类和无脊椎动物。 太平洋西北部的石莼绿色藻类大量繁殖的原因、范围和历史并不像其他地区那样为人所知。 初步研究表明，水华有能力改变海洋群落结构和多样性。 经常观察到石莼状花导致的鳗草草甸破碎化，并且花可以降低枝条密度。 在这些沃茨中，海草作为许多具有重要生态意义的物种，包括鱼类、贝类、螃蟹、鸟类和哺乳动物的栖息地和食物来源至关重要。 初步证据表明，西北太平洋绿色藻华影响共生物种的机制多种多样，可能包括藻类产生的毒素的直接和间接影响。 该项目的目标是研究太平洋西北部石莼藻华的原因和后果。与水华形成有关的环境因素将通过监测过去通常发生和没有发生水华的地点来测量。 将使用操作性田间实验来确定光和营养物对水华形成藻类的生长和生理的影响。 现场测量将用于测量藻类的放牧率，生物测定指导的分馏方法将用于分离藻类毒素。 毒理学分析将用于评估毒素对大型藻类、海草、无脊椎动物和鱼类的影响。更广泛的影响：这项研究将使人们更好地了解引发水华形成并有助于其持久性的机制。该项目将研究毒素的产生，这是一种造成石莼水华有害影响的新机制。石莼水华及其有害影响以前已经描述过;然而，这些水华影响的机制通常归因于它们窒息其他植物和动物的能力，或者归因于随着藻类分解而发生的氧气浓度降低的有害影响。 初步实验表明，直接毒性可能是重要的，这种影响不同的ulvoid藻类物种。 了解水华中最有可能造成有毒影响的物种以及目前毒素的性质，将有助于机构和水产养殖者制定管理计划。 该项目将为香农角海洋中心的研究生、西雅图太平洋大学和香农角海洋中心的本科生以及香农角海洋中心的研究生研究助理和西雅图太平洋大学的本科生研究助理提供培训。 此外，参加SPMC本科生研究经验（REU）计划和海洋科学本科少数民族计划的学生将参与该项目。 当地公民团体对其中两个研究地点特别感兴趣。 将邀请这些小组的成员协助研究，并与这些小组分享项目数据。 为了进一步加强对大型藻华的了解，将建立一个网站，提供关于藻华的一般信息、关于该项目的信息、结果和水质数据。