Federal University of Ceará, Department of Hydraulic and Environmental Engineering, Block 713, Campus Pici, Fortaleza, Ceará, Brazil; Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA.
Auburn University, School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn, Alabama, 36849, USA.
Harmful Algae. 2019 Jun;86:128-137. doi: 10.1016/j.hal.2019.05.006. Epub 2019 Jun 8.
Cyanobacteria are known to produce a wide variety of bioactive, toxic secondary metabolites generally described as hepatotoxins, neurotoxins, cytotoxins, or dermatoxins. In Brazil, the regular monitoring of cyanobacterial toxins has intensified after the death of 65 patients in a hemodialysis clinic in Caruaru in the state of Pernambuco due to microcystin exposure. The primary objective of this study was to use multivariate statistics that incorporated environmental parameters (both biotic and abiotic) to forecast blooms of cyanobacteria and their toxic secondary metabolites in 20 drinking water reservoirs managed by the Water Treatment Company of Ceará (CAGECE) in the semi-arid region of Ceará, Brazil. Across four years (January 2013 to January 2017), 114 different phytoplankton taxa were identified, including 24 cyanobacterial taxa. In general, Ceará reservoirs were dominated by cyanobacteria due to eutrophication but also because of the dry and warm climate found throughout the region. Interestingly, specific cyanobacterial taxa were influenced by different biotic and abiotic factors. For example, nitrogen-to-phosphorus (N:P) and evaporation were positively related to saxitoxin-producing taxa, especially Raphidiopsis raciborskii, while temperature, electrical conductivity, total phosphorus, and transparency (measured as Secchi depth) were positively associated with microcystin-producing taxa, such as Microcystis aeruginosa. Climate forecasts predict higher evaporation and temperatures in the semi-arid Ceará region, which will likely magnify droughts and water scarcity as well as promote toxic cyanobacterial blooms in reservoirs in the future. Therefore, understanding the factors associated with algal blooms dominated by specific taxa is paramount for water resource management.
蓝藻产生多种生物活性、有毒的次生代谢物，通常被描述为肝毒素、神经毒素、细胞毒素或皮肤毒素。在巴西，由于微囊藻暴露导致伯南布哥州卡鲁阿鲁市一家血液透析诊所的 65 名患者死亡，对蓝藻毒素的定期监测已加强。本研究的主要目的是使用多元统计方法，将环境参数（生物和非生物）纳入其中，以预测巴西塞阿拉州半干旱地区由塞阿拉供水公司（CAGECE）管理的 20 个饮用水水库中蓝藻及其有毒次生代谢物的水华。在四年（2013 年 1 月至 2017 年 1 月）期间，共鉴定出 114 种不同的浮游植物类群，包括 24 种蓝藻类群。一般来说，由于富营养化，塞阿拉水库主要由蓝藻主导，但也由于该地区全年干旱和温暖的气候。有趣的是，特定的蓝藻类群受到不同的生物和非生物因素的影响。例如，氮磷比（N：P）和蒸发与产生石房蛤毒素的类群呈正相关，特别是念珠藻，而温度、电导率、总磷和透明度（以塞奇深度衡量）与产生微囊藻毒素的类群呈正相关，如铜绿微囊藻。气候预测表明，塞阿拉半干旱地区的蒸发和温度将会升高，这可能会加剧干旱和水资源短缺，并在未来促进水库中有毒蓝藻的水华。因此，了解与特定类群藻类水华相关的因素对于水资源管理至关重要。
