Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA.
Water Res. 2012 Jul;46(11):3471-8. doi: 10.1016/j.watres.2012.03.050. Epub 2012 Apr 1.
We tested the hypothesis that zebra mussels (Dreissena polymorpha) have positive effects on the toxin-producing cyanobacterium, Microcystis aeruginosa, at low phosphorus (P) concentrations, but negative effects on M. aeruginosa at high P, with a large-scale enclosure experiment in an oligotrophic lake. After three weeks, mussels had a significantly positive effect on M. aeruginosa at ambient P (total phosphorus, TP ∼10 μg L⁻¹), and a significantly negative effect at high P (simulating a TP of ∼40 μg L⁻¹ in lakes). Positive and negative effects were strong and very similar in magnitude. Thus, we were able to ameliorate a negative effect of Dreissena invasion on water quality (i.e., promotion of Microcystis) by adding P to water from an oligotrophic lake. Our results are congruent with many field observations of Microcystis response to Dreissena invasion across ecosystems of varying P availability.
我们检验了这样一个假设，即在低磷（P）浓度下，斑马贻贝（Dreissena polymorpha）对产毒蓝藻铜绿微囊藻（Microcystis aeruginosa）有积极影响，但在高磷条件下有消极影响，为此我们在贫营养湖中进行了大规模围隔实验。三周后，在环境磷（总磷，TP∼10μg L⁻¹）条件下，贻贝对铜绿微囊藻有显著的积极影响，而在高磷条件下（模拟湖泊中约 40μg L⁻¹的 TP）则有显著的消极影响。正、负效应的强度和幅度都非常相似。因此，我们能够通过向贫营养湖水中添加 P 来缓解斑马贻贝入侵对水质（即促进微囊藻生长）的负面影响。我们的结果与许多关于不同磷供应生态系统中铜绿微囊藻对斑马贻贝入侵响应的实地观测结果一致。
