Department of Natural and Life Sciences, Faculty of Sciences, University of 20 August 1955, Skikda, Algeria.
Laboratoire de Recherche Sur La Physico-Chimie des Surfaces Et Interfaces (LRPCSI), University of 20 August 1955, Skikda, Algeria.
Environ Monit Assess. 2022 Nov 28;195(1):159. doi: 10.1007/s10661-022-10770-w.
Increased salt concentration is one of the most widespread problems affecting freshwater worldwide. Aquatic communities, and in particular periphytic diatoms, react to this alteration in water quality by modifying their structural parameters and physiology at the individual level, which is commonly manifested by the appearance of teratological forms. The present work presents the results of an experimental laboratory study in which a biofilm grown on artificial substrates was subjected to a gradient of water conductivities for 4 weeks. The results show an increase in the number of deformed valves over time proportionally to the increase in conductivity for each experimental treatment. These effects are also verified by analyzing the concentration of chlorophyll-a in the experimental biofilms, which demonstrate a metabolic response to the induced osmotic stress. No changes were recorded; however, in species richness or diversity of taxa present in the treatments. Our results, therefore, confirm at the experimental level numerous previous field observations about the harmful effect of salinity on periphytic diatoms, and also their ability to reintegrate with the new stress conditions.
盐度升高是影响全球淡水的最普遍问题之一。水生生物群落，特别是周丛藻类，通过在个体水平上改变其结构参数和生理机能来对此水质变化做出反应，通常表现为出现畸形形态。本研究报告了一项实验室内研究的结果，该研究将在人工基质上生长的生物膜暴露于水导率梯度中 4 周。结果表明，随着时间的推移，变形阀的数量会随着每个实验处理的电导率增加而呈比例增加。这些效应还通过分析实验生物膜中叶绿素-a 的浓度得到验证，该浓度证明了对诱导渗透压胁迫的代谢反应。然而，在处理中存在的分类群的丰富度或多样性方面，并未记录到任何变化。因此，我们的结果在实验水平上证实了许多先前关于盐度对周丛硅藻的有害影响的实地观察结果，以及它们适应新的胁迫条件的能力。
