RUI: Collaborative Research: Harmful Ulvoid Macroalgal Blooms in Washington State

智力优势：“绿潮”或绿色巨藻的大量繁殖在世界各地都有发生，但在温带地区最为常见。这些开花是极具生产力的社区，尽管是短暂的。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、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，绿藻繁殖被认为是导致海草草甸灭绝和动物群落结构改变的罪魁祸首。这些影响通常与遮荫和缺氧有关，但越来越多的证据表明，一些形成水华的大型藻类产生的毒素直接影响共生的藻类和无脊椎动物。发生在太平洋西北部的超级绿藻水华的原因、范围和历史并不像其他地区那样广为人知。初步研究表明，水华有能力改变海洋群落结构和多样性。经常可以观察到超空开花对eelgras草地的破坏，开花会降低新梢密度。在这些水域，海草作为许多生态重要物种的栖息地和食物来源至关重要，包括鱼类、贝类、棕榈鱼、鸟类和哺乳动物。初步证据表明，太平洋西北部的绿藻水华影响共生物种的机制各不相同，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海藻暴发的原因和后果。与水华形成相关的环境因素将通过监测水华通常发生过和过去没有发生过的地点来衡量。操纵性田间实验将被用来确定光和营养对水华形成藻类生长和生理的影响。将使用现场测量来测量对藻类的放牧率，并将使用生物测定指导的分级方法来分离藻类毒素。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：这项研究将提供对水华形成机制的更好理解，并有助于水华的持续。这个项目将研究毒素的产生，这是一种造成超空水华有害影响的新机制。超空水华及其有害影响以前已被描述过；然而，这些水华的影响机制通常被归因于它们窒息其他动植物的能力，或由于藻类分解时氧气浓度下降的有害影响。初步实验表明，直接毒性可能是重要的，这种影响在不同的球状藻类物种中是不同的。了解水华中最有可能造成有毒影响的物种和存在的毒素的性质，将有助于机构和水产养殖者制定管理计划。该项目将为香农点海洋中心(SPMC)的研究生和西雅图太平洋大学(SPU)和SPMC的本科生，以及SPMC的研究生研究助理和SPU的本科生研究助理提供培训。此外，参与国家海洋学委员会S本科生研究体验项目和少数民族海洋科学本科项目的学生将参与该项目。其中两个学习地点对当地公民团体特别感兴趣。这些小组的成员将被邀请协助研究，该项目的数据将与这些小组共享。为了进一步加强对大型藻华的了解，将建立一个网站，提供有关藻华的一般信息、关于该项目的信息、结果和水质数据。

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.