Spatial and Temporal Patterns of Fecal Indicator Bacteria in the Surface Waters of the Golden Horn Estuary

Objective: The Golden Horn Estuary is a semi-enclosed coastal system subjected to long-term anthropogenic pressures, including urbanization, industrial activities, and continuous domestic wastewater inputs. Despite extensive rehabilitation efforts, concerns remain regarding the current bacteriological quality of the surface waters. This study aimed to evaluate the spatial and temporal patterns of fecal indicator bacteria in the surface waters of the Golden Horn Estuary.Materials and Methods: Surface water samples were collected monthly from three stations representing the inner (H3), middle (H2), and outer (H1) zones of the estuary between December 2023 and May 2024. Total coliforms, fecal coliforms, and intestinal enterococci were quantified using the membrane filtration method on selective media. Bacterial levels were expressed as log cfu/100 mL and assessed in relation to national and international water quality guidelines.Results: The results demonstrated persistently elevated levels of fecal indicator bacteria throughout the study period. Clear spatial differences were observed among stations, while pronounced temporal fluctuations were evident, with higher bacterial concentrations generally recorded during the winter months. At all sampling stations, indicator bacteria levels frequently exceeded the recommended guideline limits, indicating ongoing fecal contamination within the estuary.Conclusion: These findings indicate that, despite rehabilitation initiatives, the Golden Horn Estuary remains under continuous bacteriological pressure. The study provides updated baseline data on fecal indicator bacteria and underscores the importance of sustained monitoring to support effective coastal management and public health protection.