Assessment of faecal bacteria contamination in selected coastal waters of Tanzania

Coastal communities of Tanzania use natural water systems such as rivers, estuaries and marine for various activities like drinking, fishing, washing and bathing. However, there is scanty information on the safety for these water bodies for the various intended uses. In this study faecal bacteria indicator were assessed in three sites along the coast of Tanzania (i.e. Pangani Estuary in Tanga Region, Ruvu Estuary in Pwani Region and Mzinga Creek in Dar es Salaam Region). Three sampling stations covering fresh, brackish and marine waters were selected. Sampling was conducted on a monthly basis between July 2009 and June 2010. All faecal bacteria indicators were significantly higher in fresh waters compared to brackish and marine waters (P = 0.0001), Faecal bacterial indicators were generally higher in Dar es Salaam compared to the rest of the study sites with significant differences between Dar es Salaam and Pangani for total coliforms (TC) and faecal coliforms (FC) (P < 0.05) Enterococcus (ENT) (P = 0.001). Generally the faecal bacterial indicators in the studied waters along the coast of Tanzania were within the acceptable standards according to WHO and USEPA indicating low risks situation. But the level of indicator bacteria obtained in this study does not warrant the use of fresh water for drinking. However the water can be used for recreational purposes. Further studies and monitoring programs are recommended to substantiate the current results.