The effect of environmental parameters and cyanobacterial blooms on phytoplankton dynamics of a Portuguese temperate lake
The effect of environmental parameters and cyanobacterial blooms on phytoplankton dynamics of a Portuguese temperate lake
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DOI：
10.1007/s10750-006-0196-y
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发表时间：
2006-09-01
期刊：
影响因子：
2.6
通讯作者：
Pereira, Mario J.
中科院分区：
文献类型：
--
作者：
de Figueiredo, Daniela R.;Reboleira, Ana S. S. P.;Pereira, Mario J.
由于许多蓝藻能够产生蓝藻毒素，淡水中蓝藻水华的发生越来越多，引起了人们的极大关注。在目前的工作中，富营养化的贝拉湖（葡萄牙中部），用于娱乐目的，并作为农业水源，监测每两周之间的2000年和2001年。浮游植物的多样性和密度进行了测量，并与环境参数。季节性植物群落演替的观察，它主要是与电导率，温度，总悬浮固体和营养物质的可用性（特别是磷）。硅藻占主导地位，在冬季的几个月（较低的温度和较高的养分供应），其次是绿色藻类在早春，然后蓝藻从晚春到初秋（较少的养分供应和较高的温度）。2001年5月初，水华束丝藻发生了大规模的蓝藻水华，在此之前，在整个研究期间，水中测得的氮含量最低。在这个开花衰老的时候，溶解氧被严重耗尽，大量的鱼类动物死亡。此外，在二零零一年七月亦发现铜绿微囊藻水华，而该水华是在绿色藻类及硅藻数量迅速减少后出现的。通过考虑不仅是环境参数，但也发生蓝藻水华的解释变量在典型的对应分析中，解释的方差在研究期间的植物共生组合增加了约7%，实现了61.0%，表明相关性，可能是由于已知的竞争优势和/或化感作用的水华形成蓝藻对微藻。
The increasing occurrence of cyanobacterial blooms in freshwaters is of great concern due to the ability of many cyanobacteria to produce cyanotoxins. In the present work, the eutrophied Vela Lake (Central Portugal), used for recreational purposes and as a water source for agriculture, was monitored every fortnight between 2000 and 2001. Phytoplankton diversity and densities were measured and correlated to environmental parameters. A seasonal phytoplanktonic succession was observed and it was mainly correlated with conductivity, temperature, total suspended solids and nutrients availability (particularly phosphorus). Diatoms were dominant during winter months (inferior temperatures and higher nutrients availability) followed by green algae in early spring and then cyanobacteria from late spring until early autumn (less nutrient availability and higher temperatures). A massive cyanobacterial bloom of Aphanizomenon flos-aquae occurred early in May 2001 and was preceded by the lowest nitrogen levels measured in the water during all the study period. At the time of this bloom senescence, dissolved oxygen was severely depleted and a massive death of ichthyofauna was recorded. A Microcystis aeruginosa bloom was also detected in July 2001 and it occurred following a rapid decrease in abundance of green algae and diatoms. By considering not only the environmental parameters but also the occurrence of cyanobacterial blooms as explanatory variables in a canonical correspondence analysis, the variance explained for the phytoplanktonic assemblage during the study period was increased in about 7% achieving a total of 61.0%, indicating a correlation that may be due to the known competitive advantage and/or allelopathy of the bloom-forming cyanobacteria towards microalgae.