UMR 7245 MCAM MNHN-CNRS, Equipe Cyanobactéries, Cyanotoxines et Environnement, Muséum National d'Histoire Naturelle, Case 39, 12 rue Buffon, F-75231 Paris Cedex 05, France.
Water Res. 2012 Apr 15;46(6):1771-84. doi: 10.1016/j.watres.2011.12.056. Epub 2012 Jan 16.
Although microscope analysis is very useful for studying phytoplankton community composition, it does not allow for high frequency (spatial and/or temporal) data acquisition. In an attempt to overcome this issue, fluorescence-based approaches that use selective excitation of pigment antennae have spread rapidly. However, the ability of spectral fluorescence to provide accurate estimates of phytoplankton biomass and composition is still debated, and only a few datasets have been tested to date. In this study, we sampled of a wide range of water bodies (n=50) in the Ile-de-France region (North Central France). We used the resulting extensive dataset to assess the ability of the bbe-Moldaenke FluoroProbe II (FP) to estimate phytoplankton community composition in lakes and reservoirs. We demonstrated that FP data yields better estimates of total phytoplankton biovolume than do spectrophotometric chlorophyll a measures and that FP data can be further corrected using the average chlorophyll a to biovolume ratio among phytoplankton groups. Overall, group-specific relationships between FP and biovolume data were consistent. However, we identified a number of cases where caution is required. We found that Euglenophytes are expected to depart from the global FP vs. biovolume relationship of the 'green' group due to varying Fv/Fm and pigment content in response to environmental conditions (photoautotrophic vs. photoheterotrophic growth). Then, it appears necessary to consider the composition of the Chromophytes community in order to obtain a good agreement between both biomass estimation methods. Finally, we confirmed the misattribution toward the 'red' group of phycoerythrin-containing cyanobacteria and the occurrence of a strong scattering in the relationship between the FP vs. biovolume of the 'blue' group that can be partly attributed to the occurrence of large colony-forming cyanobacteria (e.g., Microcystis spp, Aphanizomenon flos-aquae). We propose correcting procedures to improve the quality of data obtained from spectral fluorescence tools in the context of large-scale sampling of lakes and reservoirs.
虽然显微镜分析对于研究浮游植物群落组成非常有用，但它不允许进行高频（空间和/或时间）数据采集。为了克服这个问题，基于荧光的方法迅速传播开来，这些方法利用色素天线的选择性激发。然而，光谱荧光提供浮游植物生物量和组成的准确估计的能力仍有争议，迄今为止，只有少数数据集进行了测试。在这项研究中，我们在法兰西岛地区（法国中北部）采集了广泛的水体样本（n=50）。我们利用由此产生的广泛数据集来评估 bbe-Moldaenke FluoroProbe II（FP）在湖泊和水库中估算浮游植物群落组成的能力。我们证明 FP 数据可以更好地估计总浮游植物生物量，而不是分光光度法测定的叶绿素 a 测量值，并且可以使用浮游植物组之间的平均叶绿素 a 与生物量比进一步校正 FP 数据。总体而言，FP 与生物量数据之间的特定于组的关系是一致的。但是，我们确定了一些需要谨慎的情况。我们发现，由于环境条件下的 Fv/Fm 和色素含量的变化（自养生长与异养生长），眼虫藻预计会偏离“绿色”组的全局 FP 与生物量关系。然后，似乎有必要考虑 Chromophytes 群落的组成，以获得两种生物量估计方法之间的良好一致性。最后，我们证实了含藻红蛋白的蓝藻被错误地归属到“红色”组，并且 FP 与“蓝色”组生物量之间的关系存在强烈的散射，这在一定程度上归因于大型形成菌落的蓝藻（例如，微囊藻属、鱼腥藻属）的出现。我们提出了校正程序，以提高从光谱荧光工具获得的数据质量，这些数据是在湖泊和水库的大规模采样背景下获得的。
