Littoral Greening: A Workshop to Understand the Drivers of Attached Filamentous Algal Blooms in Pristine Lakes; October, 2019 Lake Tahoe (CA-NV, USA)

在世界各地的原始、高水质湖泊中观察到了一种令人费解的海岸退化模式，包括美国的太浩湖、新西兰的瓦基蒂普湖和塔普湖以及俄罗斯的贝加尔湖。湖泊的近岸和底缘是绿色的，尽管这些湖泊所在的流域干扰相对较小，湖泊的营养成分也很低。初步观察表明，变绿是由于藻类和细菌的过度生长，这些藻类和细菌现在正在对这些湖泊的生态和依赖它们的人造成影响。那么，为什么这些藻类水华现在在水质较高的湖泊中很常见？它们很可能是许多因素的结果，随着环境变化的进展，这些因素正在以新的方式相互作用。这次研讨会汇集了来自多个科学学科的专家，讨论这些变化，并确定必须回答的关键问题，以解释为什么水质良好的湖泊突然发生变化。组织者将招募科学界代表性不足的成员参与这一主题，并在一份公众可通过互联网访问的出版物中创建一份研讨会发现的摘要论文。将在至少一次国际科学会议期间设立一次特别科学会议，邀请湖泊系统的科学家和管理者继续就这一主题进行讨论。这是第一次讨论生态系统科学中出现的这一问题的研讨会。研讨会的主要目标是开发概念模型，以解释为什么通常不起眼的丝状藻类突然在湖泊近岸底部繁殖到滋扰水平。概念模型将通过围绕基本研究问题的讨论来开发，这些问题突出了丝状藻类生长的潜在机制，包括但不限于：1)气候引起的物理条件变化如何影响近岸地区的营养物质和沉积物动力学？2)偏远湖泊是否经历了人为地下水污染带来的营养负荷增加？3)动物食草动物和不断变化的生物群落在促进底层藻类生长中所起的作用？4)与湖岸开发和大气负荷相关的营养物质可获得性的适度增加是否有利于丝状绿藻和蓝藻的生长？在面对面会议之前，将举行一系列通过视频会议的预会议，以最大限度地讨论和开发概念模型和为这一新出现的问题确定的关键问题的答案。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

A puzzling pattern of coastal degradation has been observed in pristine, high water quality lakes around the world, including Lake Tahoe in the USA, Lakes Wakitipu and Taupō in New Zealand, and Lake Baikal in Russia. The nearshore and bottom edges of lakes are greening even though the watersheds in which these lakes reside have relatively low disturbance and the lakes are low in nutrients. Initial observations suggest the greening is from excessive growth of algae and bacteria that are now having consequences for the ecology of these lakes and the people that rely on them. So why are these algal blooms now common in lakes with high water quality? They are likely a result of many factors that are now interacting in new ways as environmental changes progress. This workshop brings together experts from a many science disciplines to discuss these changes and identify key questions that must be answered to explain why lakes with good water quality are suddenly changing. The organizers will recruit underrepresented members in science to engage in the topic and create a summary paper of the workshop findings in a publication that is accessible to the public via the internet. A special science session within at least one international science meeting will be created to engage scientists and managers of lake systems to continue discussions on this topic. This is the first workshop to address this emerging issue in ecosystem science. The primary workshop goals are to develop conceptual models to explain why usually inconspicuous filamentous algae are suddenly proliferating to nuisance levels in the nearshore-bottom of lakes. The conceptual models will be developed through discussions around basic research questions that highlight the potential mechanisms contributing to filamentous algae growth including but not limited to 1) How do climatically-induced changes in physical conditions affect nutrient and sediment dynamics in the nearshore zone? 2) Are remote lakes experiencing increased nutrient loading from anthropogenic groundwater pollution? 3) What is the role of animal grazers and changing biological communities in contributing to bottom algae growth? 4) Do moderate increases in nutrient availability associated with lakeshore development and atmospheric loading favor the growth of filamentous green algae and cyanobacteria? A series of premeetings via video conference will occur prior to the in-person meeting to maximize discussions and development of the conceptual models and answers to the key questions identified for this emerging issue.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.