ISARA-Lyon, Equipe Ecosystèmes et Ressources Aquatiques, 23 rue Jean Baldassini 69364 Lyon Cedex 07, France.
Water Res. 2011 Jan;45(3):1005-14. doi: 10.1016/j.watres.2010.10.011. Epub 2010 Oct 20.
Sampling cyanobacteria in freshwater ecosystems is a crucial aspect of monitoring programs in both basic and applied research. Despite this, few papers have dealt with this aspect, and a high proportion of cyanobacteria monitoring programs are still based on monthly or twice-monthly water sampling, usually performed at a single location. In this study, we conducted high frequency spatial and temporal water sampling in a small eutrophic shallow lake that experiences cyanobacterial blooms every year. We demonstrate that the spatial and temporal aspects of the sampling strategy had a considerable impact on the findings of cyanobacteria monitoring in this lake. In particular, two peaks of Aphanizomenon flos-aquae cell abundances were usually not picked up by the various temporal sampling strategies tested. In contrast, sampling once a month was sufficient to provide a good overall estimation of the population dynamics of Microcystis aeruginosa. The spatial frequency of sampling was also important, and the choice in the location of the sampling points around the lake was very important if only two or three sampling points were used. When four or five sampling points were used, this reduced the impact of the choice of the location of the sampling points, and allowed to obtain fairly similar results than when six sampling points were used. These findings demonstrate the importance of the sampling strategy in cyanobacteria monitoring, and the fact that it is impossible to propose a single universal sampling strategy that is appropriate for all freshwater ecosystems and also for all cyanobacteria.
在淡水生态系统中采样蓝藻是基础和应用研究监测计划的关键方面。尽管如此，很少有论文涉及这一方面，而且仍然有很大比例的蓝藻监测计划基于每月或每两个月一次的水样采集，通常在一个地点进行。在这项研究中，我们在一个每年都会发生蓝藻水华的小型富营养化浅湖中进行了高频时空水采样。我们证明，采样策略的时空方面对该湖中蓝藻监测的结果有很大影响。特别是，各种测试的时间采样策略通常无法捕捉到水华束丝藻细胞丰度的两个峰值。相比之下，每月采样一次足以提供对铜绿微囊藻种群动态的良好总体估计。采样的空间频率也很重要，如果只使用两个或三个采样点，那么在湖泊周围选择采样点的位置非常重要。当使用四个或五个采样点时，这减少了采样点位置选择的影响，并允许获得与使用六个采样点时相当相似的结果。这些发现表明了采样策略在蓝藻监测中的重要性，事实上，不可能提出一种适用于所有淡水生态系统和所有蓝藻的单一通用采样策略。
