Department of Fisheries and Wildlife, Michigan State University, 13 Natural Resources Building, East Lansing, MI 48824, Michigan, USA.
Water Res. 2010 Jan;44(1):141-50. doi: 10.1016/j.watres.2009.09.014. Epub 2009 Sep 11.
An existing volunteer monitoring network in the state of Michigan was exploited to conduct a statewide survey of the cyanobacterial toxin, microcystin, and to test hypotheses about the interactive influences of eutrophication and dreissenid mussel invasion. A total of 77 lakes were sampled by citizen volunteers for microcystin, total phosphorus (TP) and chlorophyll a. Microcystin was measured in depth-integrated samples collected from the euphotic zone as well as in surface-water samples collected along the shoreline. Average microcystin in samples collected by volunteers was not different from samples collected side-by-side by professionals. Euphotic-zone microcystin was positively related to TP in lakes without dreissenids (uninvaded) but not in lakes with dreissenids (invaded). Regression-tree analysis indicated that euphotic-zone microcystin was eight times higher in the presence of dreissenids for lakes with TP between 5 and 10microgL(-1). In contrast, euphotic-zone microcystin was almost identical in invaded and uninvaded lakes with TP between 10 and 26microgL(-1). Across all lakes, microcystin concentrations at the surface were on average more than double, and in some cases an order-of-magnitude greater than, concentrations in the euphotic-zone. Given these results, it seems prudent to include dreissenid invasion status in forecasting models for microcystin, and to include shoreline sampling in monitoring programs aimed at assessing recreational exposure to cyanobacterial toxins.
利用密歇根州现有的志愿者监测网络，对该州的蓝藻毒素微囊藻进行了全州范围的调查，并对富营养化和双壳类贻贝入侵的相互影响假设进行了测试。共有 77 个湖泊由公民志愿者采集微囊藻、总磷 (TP) 和叶绿素 a。在透光区采集深度积分样本和沿湖岸线采集表层水样，以测量微囊藻。志愿者采集的样本中的平均微囊藻与专业人员并排采集的样本没有差异。在没有双壳类贻贝（未入侵）的湖泊中，透光区微囊藻与 TP 呈正相关，但在有双壳类贻贝（入侵）的湖泊中则没有相关性。回归树分析表明，对于 TP 在 5 到 10microgL(-1) 之间的湖泊，有双壳类贻贝存在时，透光区的微囊藻含量要高出 8 倍。相比之下，TP 在 10 到 26microgL(-1) 之间的入侵和未入侵湖泊的透光区微囊藻含量几乎相同。在所有湖泊中，表层的微囊藻浓度平均是透光区浓度的两倍以上，在某些情况下，表层浓度是透光区浓度的一个数量级以上。鉴于这些结果，在预测微囊藻模型时似乎需要将双壳类贻贝入侵状况纳入其中，并在旨在评估公众接触蓝藻毒素的监测计划中纳入沿湖岸线的采样。
