Résumé:
Garaet Beni M'hamed is the largest lake in the wetland complex Guerbes Sanhadja with an area of 380 hours during the months of March and April 2015 we conducted sampling at two different places on the site to perform hydrochemical and bacteriological analyzes phytoplankton.
The results we have obtained in our study about water hydrochemistry of Garaet Beni M'hamed indicate that the waters of Garaet in average quality regarding some parameters such as BOD indicating high organic matter load. For bacteriology at this lake which is noted is a faecal pollution that resulted in a high rate of faecal coliforms and spores of sulfite-reducing bacteria and the presence of some pathogenic germs . Regarding phytoplankton we have identified 24 species indicating a diversity of phytoplankton at our site.
Finally, we note that these ecosystems are slightly polluted and this mainly due to intensive farming, agriculture and the presence of large numbers of waterfowl
