Raw absorbance and fluorescence measurements of water samples during Nodularia spumigena bloom event on Lake Bante in Wilhelmshaven, Germany

Water sampling was conducted aboard a small electric motor powered vessel on Lake Bante in Wilhelmshaven, Germany during a Nodularia spumigena bloom event (25 August 2022). Samples were kept in the dark and stored at below -4 °C until further analyses were conducted. First the samples were pre-filtered through Whatman GF/F filters with a 0.7 µm mesh. Further filtration was done using Whatman Nuclepore Track-Etch 0.2 µm pore size membranes within 2 weeks after field sampling. Excitation-emission matrices (EEMs) and absorbance measurements were done using a Horiba Aqualog benchtop fluorometer. Sample filtrate was placed in a 1 cm quartz cuvette that had been pre-rinsed 3 times before each measurement.

2022年8月25日，于德国威廉港（Wilhelmshaven）的班特湖（Lake Bante）上，搭乘小型电动船舶开展水样采集作业，彼时正处于泡沫节球藻（Nodularia spumigena）水华暴发期。采集所得样本全程避光保存，并存储于-4℃以下环境中，直至开展后续分析。首先，样本经孔径0.7 µm的Whatman GF/F滤膜进行预过滤；野外采样后的2周内，使用孔径0.2 µm的Whatman Nuclepore Track-Etch径迹蚀刻膜完成二次过滤。采用Horiba Aqualog台式荧光光度计开展激发发射矩阵光谱（Excitation-emission matrices, EEMs）与吸光度测定：将样本滤液置于1 cm光程的石英比色皿内，且每次测量前该比色皿均需预先冲洗3次。