Integrating top-down control by parasitic protists and fungi into the ecological dynamics of freshwater phytoplankton blooms

将寄生原生生物和真菌的自上而下控制纳入淡水浮游植物水华的生态动力学中

• 批准号: NE/X012204/1
• 负责人: Joe Taylor
• 金额: $ 12.52万
• 依托单位: UK CENTRE FOR ECOLOGY & HYDROLOGY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX012204%2F1
• 关键词: Integrating; top; down; control; parasitic

Freshwater lakes provide us with many services such as a supply of freshwater for our homes and recreation. Within freshwater lakes, microalgae, photosynthesising single cells, increase in numbers throughout the spring and summer. Different species of algae "bloom" at different times of the year and are usually a normal part of the lake ecosystem. However, sometimes these blooms can become a nuisance, produce toxic chemicals (such as blue-green algae), or simply turn the water a green pea soup colour, shading out other plants. Blooms of algae may impact on all life within the lakes. With increasing nutrient inputs from sewage and agriculture, increasing temperature and extreme whether events, algal blooms are happening more frequently and with longer duration. What controls these blooms is largely attributed either bottom-up factors (availability of light, temperature, nutrients) or top-down factor (predation and grazing by zooplankton). One less known top-down control of algae is parasitism. Algae are parasitised by many different organisms. The most well-known are tiny single-celled species of fungi called Chytrids that infect cells of algae killing them. There are also diverse groups of other life such as different species of single celled protozoa that may control algae numbers through parasitism. Many parasites of algae within the UK are not well known and only described from microscope observations in the last century. This project will use cutting edge DNA sequencing technology combined with microscopy and flow cytometry to identify and count parasites of algae within the lakes of Lake district UK. It will look at samples across different seasons and from 20 different lakes. It also will track parasite abundance and diversity across the lifetime of an algal bloom. The project will look at the impact these parasites have on blooms of algae, showing how their numbers increase and decrease in relation to their algal hosts. This will enable us to increase our knowledge of top-down controls on blooms of algae, learning more about their ecology and will helpi us to better understand, predict and manage algae and the health of freshwater ecosystems.

淡水湖泊为我们提供许多服务，例如为我们的房屋和娱乐供应淡水。在淡水湖中，微藻，光合作用的单细胞在整个春季和夏季增加。一年中的不同时间，不同种类的藻类“开花”，通常是湖泊生态系统的正常部分。但是，有时这些花朵会变成滋扰，产生有毒的化学物质（例如蓝绿色藻类），或者简单地将水变成绿色的豌豆汤颜色，从而遮盖其他植物。藻类的花朵可能会影响湖泊内的所有生命。随着污水和农业的养分投入增加，温度和极端的升高，是否发生藻华的发生频率更高，持续时间更长。控制这些花朵的原因很大程度上归因于自下而上的因素（光，温度，营养素的可用性）或自上而下的因子（浮游动物的捕食和放牧）。寄生虫的一个鲜为人知的自上而下控制。藻类被许多不同的生物寄生。最著名的是称为chytrids的细小真菌，它们会感染藻类的细胞杀死它们。还有其他生命的各种群体，例如不同种类的单细胞原生动物，可以通过寄生虫控制藻类数量。英国域内的许多藻类寄生虫尚不广为人知，仅从上个世纪的显微镜观察中描述了。该项目将使用尖端的DNA测序技术与显微镜和流式细胞仪相结合，以识别和计算英国湖区湖中藻类的寄生虫。它将查看不同季节和20个不同湖泊的样品。它还将跟踪藻类绽放一生中的寄生虫丰度和多样性。该项目将探讨这些寄生虫对藻类花朵的影响，以表明其数量与藻类宿主相关的增加和减少。这将使我们能够提高对藻类花朵上自上而下的控制的了解，了解更多有关其生态的知识，并帮助我们更好地理解，预测和管理淡水生态系统的藻类和健康。