Cyanobacteria and cyanotoxin trends: determining historical and contemporary relationships with eutrophication and climate warming

世界各地的淡水正在经历藻类大量繁殖，直接和间接地影响水生生态系统，它们提供的服务，甚至人类健康。蓝细菌（蓝绿藻）水华特别令人关切，因为它们往往含有可能影响野生动物、牲畜、家畜和人类的毒素。在加拿大，至少在安大略和魁北克，湖泊中蓝藻水华的发生率似乎越来越高，然而，这可能仅仅是由于更好的报告，因为大多数湖泊和河流的长期监测很少。此外，这些趋势很有可能因气候变暖而加剧。该项目旨在通过经验，实验和古湖泊学研究相结合，确定蓝藻优势的环境触发因素，特别是潜在的蓝藻的驱动因素。这将需要对文献和未发表的数据库进行全面综合，以确定蓝藻优势是否存在共同的营养阈值，或者该阈值是否因区域和气候变量而异。在加拿大四个地区进行的古湖泊学研究将有助于确定蓝藻水华何时开始以及导致蓝藻水华爆发的因素。将确定最常见的蓝藻毒素（肝毒性微囊藻毒素）在湖泊沉积物中的持久性，并将审查其作为过去有毒水华的潜在指标的用途。来自联邦和省级部门以及地方市政当局的环境机构是该项目的支持组织。

Freshwaters around the world are experiencing algal blooms which directly and indirectly are affecting aquatic ecosystems, the services they provide and even human health. Cyanobacterial (blue-green algal) blooms are of particular concern because they often contain toxins that can affect wildlife, livestock, domestic animals and humans. In Canada there appears to be an increasing incidence of cyanobacterial blooms in lakes, at least in Ontario and Quebec, however, this could simply be due to better reporting since most lakes and rivers have minimal long-term monitoring. Furthermore, there is a strong possibility that these trends are and will be aggravated by climate warming. This project aims to identify, through a combination of empirical, experimental and paleolimnological studies, the environmental triggers of cyanobacterial dominance and, in particular, the drivers of potentially toxigenic cyanobacteria. This will entail a comprehensive synthesis of literature and unpublished data bases to determine whether there is a common nutrient threshold for cyanobacteria dominance or whether this threshold differs across regions and in response to climate variables. Paleolimnological studies in four regions of Canada will help determine when cyanobacterial blooms began and what factors led to their onset. The persistence in lake sediments of the most common cyanotoxins (the hepatotoxic microcystins) will be determined and their use as a potential indicator of past toxic blooms will be examined. Environmental agencies from federal and provincial departments as well as local municipalities are among the supporting organizations for this project.