Ecology of cyanobacteria and the role of cyanotoxins

水生生态系统受到多种人为压力的影响：过量的营养负荷、入侵物种和气候变化正在影响世界各地的湖泊和河流。一个非常明显的后果似乎是蓝藻水华的数量和/或频率增加。这些水华还可能产生对野生动物、人类健康和当地经济产生影响的强效毒素。然而，导致有毒蓝藻水华的具体环境条件是复杂的，并没有得到很好的理解。在湖泊中，虽然营养素通常是蓝藻水华的主要原因，但在营养素没有任何变化的情况下观察到蓝藻水华的增加，并提出了其他因果或促成因素，即气候变化和入侵物种。该研究计划旨在确定：1）可能独立于营养物的湖泊中蓝藻优势和蓝藻毒素生产的驱动因素，以及2）蓝藻毒素的生物和生态作用仍不清楚。该方法将包括实验室实验比较分离菌株的蓝藻（毒素和非毒素生产）和湖泊生态系统分析沿着气候梯度（横跨安大略/魁北克），并作为一个功能的入侵斑马贻贝和水生植物。这项研究将有助于湖泊的管理和保护水生生态系统健康的缓解措施。

Aquatic ecosystems are subject to multiple anthropogenic stressors: excess nutrient loading, invasive species and climate change are impacting lakes and rivers worldwide. One highly visible consequence appears to be an increase in the magnitude and/or frequency of cyanobacterial blooms. These blooms can also produce potent toxins with repercussions on wildlife, human health and local economies. However, the specific environmental conditions leading to toxic cyanobacterial blooms are complex and not well understood. In lakes, while nutrients are typically the primary cause of cyanobacterial blooms, increases have been observed in the absence of any change in nutrients, and other causal or contributing factors have been suggested, namely climate change and invasive species. This research programme aims to determine: 1) the drivers of cyanobacterial dominance and cyanotoxin production in lakes that may be independant of nutrients, and 2) the biological and ecological role(s) of cyanotoxins which remain unclear. The approach will include laboratory experiments comparing isolated strains of cyanobacteria (both toxin and non-toxin producing) and lake ecosystem analyses along climate gradients (across Ontario/Quebec) and as a function of invasive zebra mussels and aquatic plants. This research will assist in the management of lakes and in mitigation measures to protect the health of aquatic ecosystems.