Résumé:
Man is exerting various pressures linked to his economic activities and the daily discharge of wastewater into the sea. This human activity has resulted in industrial and microbiological pollution affecting seawater, sediments, flora and fauna. This pollution, particularly bacteriological pollution, can damage the health of biodiversity, threatening the survival of marine species. In addition, there is a risk of modifying physico-chemical parameters.
This research study is divided into two parts: firstly, a study of physico-chemical parameters and secondly, a bacteriological culture of seawater at the Salamandre and Sidi Majdoub sites, at different distances.
The PH meter, conductivity meter and turbidity meter were used to assess physico-chemical parameters such as salinity, temperature, hydrogen potential (PH), conductivity and turbidity.
In parallel, bacteriological culture using specific culture media such as PCA for total germs, VRBL for total coliforms and faecal coliforms, Berd perker for Staphylococcus aureus, and Schubert for Escherichia coli, enabled phenotypic identification of the germs from the stock solution and the various decimal dilutions carried out in physiological water.
After sampling at these two sites, Salamandre and Sidi Sidi Majdoub, at different distances (01m and 10m), the results obtained showed that the pH of the seawater at each site was within the norms, varying between 8 and 8.15. Turbidity at Salamandre was between 4,3 and 4.4 NTU, but those at Sidi Majdoub fluctuated between 3.01 and 3.4 NTU, indicating slightly turbid seawater. It was noted that the quantity of dissolved salts in the water at the Salamandre and Sidi Majdoub sites ranged between 39.4 and 39.80 mg/l. Conductivity, assessed at different distances (1m and 10m), showed an almost standard and identical value, with a peak of 56.28ms/cm. Temperature fluctuated between a minimum of 16°C and a maximum of 20°C.
On the other hand, according to the results obtained following the various colony counts after culture from the decimal dilutions, the bacterial concentration values could be a factor in marine bacterial pollution because their concentrations exceeded the guide value according to the official microbiology journal, as was the case for total germs, total coliforms and Staphylococus aureus. On the other hand, those obtained from stock solutions were within the standards and below the guide values.
At the end of this study, carried out during the months of February, March and April, we were able to conclude that the state of these two sites, Salamandre and Sidi Majdoub, assessed at different distances, is virtually free of any bacteriological pollution, although based on the cultures obtained from the mother solution, total coliforms, identified from decimal dilutions and referring to the official microbiology journal, could be a factor in marine bacterial pollution.
