Expansion, toxicity and impact of cyanobacteria in a changing world

蓝藻，通常被称为蓝绿藻，经常出现在新闻中，因为它们倾向于在湖泊和沿海地区形成表面水华，有些大到足以被卫星看到。来自农业或城市来源的过量营养素（磷和氮）是蓝藻增加的主要原因，但气候变化也可能导致这种“粘液的增加”。加拿大目前在相对低营养的湖泊和靠近北极圈的高纬度地区正在经历不寻常的蓝藻水华，那里没有关于这种水华的传统知识。蓝细菌的优势可能会产生负面影响，因为可能会产生强效毒素，这可能会影响饮用水供应，娱乐活动和财产价值。 该研究计划将采用新技术研究湖泊沉积物，以发现几个世纪以来蓝藻水华的起源和原因。我们已经表明，有可能从古代沉积物中提取高质量的DNA，并扩增蓝藻和其他微生物基因，从而在缺乏当前监测数据的情况下开始重建蓝藻种群和群落的历史。未来五年这项研究的目标是根据土地利用变化和全球气候变化解释有毒蓝藻的明显地理扩张、增加和影响。具体目标是：1）验证沉积物DNA（古DNA）记录的解释，2）确定气候变化是否导致北方纬度蓝藻优势，有毒物种和蓝藻毒素的变化，3）确定蓝藻的增加是否影响生态系统服务，特别是湖泊作为碳汇的能力。这些目标是我的长期目标的一部分，即为管理和保护淡水资源提供工具。了解温带和高纬度湖泊的过去轨迹将使我们能够更好地预测北方湖泊将如何应对气候和土地利用变化，并为环境和公共卫生政策提供信息。该研究方案将培养几名高素质的人员（8名B.Sc.，4名硕士和2名博士），他们将接触到水生科学和分子生物学的经典和现代技术，从而获得水资源管理和环境科学职业的宝贵技能。

Cyanobacteria, commonly referred to as blue-green algae, are frequently in the news because of their tendency to form surface blooms in lakes and coastal areas, some large enough to be seen by satellites. Excess nutrients (phosphorus and nitrogen) from agricultural or municipal sources are largely responsible for increases in cyanobacteria, but climate change may also be contributing to this “rise of slime”. Canada is now experiencing unusual cyanobacterial blooms in relatively low nutrient lakes and at high latitudes close to the Arctic Circle, where there is no traditional knowledge of such blooms. Cyanobacterial dominance can have negative effects because of the potential production of potent toxins, which can affect drinking water supplies, recreational activities and property values.******* This research programme will apply novel techniques to the study of lake sediments in order to discover the origin and causes of cyanobacterial blooms over the scale of centuries. We have shown that it is possible to extract quality DNA from ancient sediments and amplify cyanobacterial and other microbial genes to begin the reconstruction of the history of cyanobacterial populations and communities in the absence of current monitoring data. The goal of this research for the next five years is to explain the apparent geographic expansion, increase and impact of toxic cyanobacteria, in light of land use changes and global climate change. The specific objectives are to: 1) validate the interpretation of sediment DNA (paleoDNA) records, 2) determine if climate change is leading to changes in cyanobacterial dominance, toxic species and cyanotoxins at northern latitudes, 3) determine if increases in cyanobacteria are affecting ecosystem services, particularly the capacity for lakes to serve as a carbon sink. These objectives are part of my long-term goal to provide tools for the management and protection of freshwater resources. Understanding the past trajectories of temperate and high latitude lakes will enable us to better predict how northern lakes will respond to climate and land use change, and inform environmental and public health policies.*The research programme will train several highly qualified personnel (8 B.Sc., 4 M.Sc. and 2 Ph.D.), who will be exposed to classical and modern techniques in aquatic sciences and molecular biology thus gaining valuable skills for careers in water resources management and environmental sciences.***