Diversity Of Diatom Epilithons And Quality Of Water From The Subbasin Of Oued Mina (district Of Tiaret, Algeria)
M. Negadi, A. Hassani, M. Ait Hammou, W. Dahmani, M.D. Miara, M. Kharytonov, O. Zhukov
After two years of work, we have explored most of water systems of the western region of Tiaret areas; represented mainly by the Oued Mina and Oued Louhou. The study started with a sampling, executed successively during Autumn and Spring, with the aim to identify the diatomic flora on the first part; and to analyze the ecology of these diatoms on the other part, regarding the Environmental factors through canonical correspondence analysis in order to estimate the organic pollution index. Our results highlighted 104 inventoried species, distributed on 20 different families, with 13 new taxa as a new record in Algeria: Brachysira microcephala, Eunotia cataractarum, Hippodonta capitata, Luticola kotschyi, Luticola nivalis Neidium binodeforme, Neidium ampliatum, Neidium dubium, Nitzschia bita, Nitzschia sinuata var. Tabellaria. Pinnularia obscura, Stauroneis gracilis and Surirella crumena. Otherwise, the calculation of the Organic Pollution Index OPI along the describing stations shows a degraded condition of the quality of water in Oued Mina, due to the discharge of domestic and industrial waste water from agglomerations. Four functional groups of the diatoms were revealed. A functional group A is presented by 21 species. The high trophy preference is a most important ecological property of the functional group A. Species which constitute this functional group are mainly eutraphentic. A functional group B is presented by 10 species. Species which constitute this functional group are mainly acidophilous. A functional group C is presented by 20 species. The preference of the low nitrogen level is a most important ecological property of the functional group C. A functional group D is presented by 8 species. Species which constitute this functional group are mainly facultatively nitrogen-heterotrophic taxa needing periodically elevated concentration of organically bound nitrogen.