Bacteria and Nutrients as Pollution Indicators in the Al-Nawrus Recreational Lagoon,

Environmental pollution that renders shore waters unsatisfactory for public use has become a global health problem. This study was carried out to examine certain pollution-indicating water quality parameters in sampling stations located at Al-Nawrus lagoon (North of Jeddah) during June 2005 - January 2006. These parameters included: aerobic heterotrophic bacteria, total coliform (TC), fecal coliform (FC), dissolved oxygen (DO), and nutrients (NO2-N, NO3-N, NH4-N and PO4-P). DO and nutrient concentrations varied greatly in the water at different sampling stations compared with their respected values in the open sea. A comparison of the mean values of nutrients in Al-Nawrus lagoon with those of other locations in the Red Sea suggests that the mean levels of NO3 were similar to those of polluted areas, whereas mean concentrations of NO2, NH4 and PO4 were generally similar to those of unpolluted or slightly polluted areas. Counts of aerobic heterotrophic bacteria, TC and FC did not show any seasonal pattern. Highest counts of aerobic heterotrophic bacteria were obtained at stations towards the north and the lowest were recorded at stations toward the south. Similarly, TC and FC counts were higher at the north sampling stations than the south ones, and with little variations between their numbers. FC was not recovered at stations to the south. The study shows that aerobic heterotrophic bacteria, except at certain sampling stations similar to the levels reported for normal unpolluted sea water.