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水华，这直接和间接地影响着水生生态系统，影响着它们提供的服务，甚至影响着人类的健康。蓝藻(蓝藻)水华特别令人担忧，因为它们经常含有影响野生动物、牲畜、家畜和人类的毒素。在加拿大，湖泊蓝藻水华的发生率似乎在增加，至少在安大略省和魁北克省是这样，然而，这可能只是由于报告得更好，因为大多数湖泊和河流都只有最低限度的长期监测。此外，气候变暖很可能会加剧这些趋势。该项目旨在通过经验、实验和古免疫学相结合的研究，确定蓝藻优势的环境触发因素，特别是潜在产毒蓝藻的驱动因素。这将需要对文献和未发表的数据库进行全面的综合，以确定蓝藻优势是否存在共同的营养阈值，或者该阈值是否因地区和气候变量的不同而不同。对加拿大四个地区的古水华研究将有助于确定蓝藻水华开始的时间以及导致它们发生的因素。将确定最常见的氰基毒素(肝毒性微囊藻毒素)在湖泊沉积物中的持久性，并将审查它们作为过去有毒水华的潜在指示器的用途。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助组织之一。

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 This will entail a comprehensive synthesis of literature and unpublished data bases to determine whether there is a common nutrient threshold for cyanobacteria dominance or whether this threshold differs across regions and in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.