Faecal indicator bacteria present in sand at South Port Beach, South Australia

Research has demonstrated that bacterial pathogens present in beach sand may be a risk to human health. The indicator species enterococci, total coliforms, and Escherichia coli were measured in beach sand collected from South Port Beach, South Australia, a popular recreational beach. Samples were collected from five distances from the low tide mark (low tide, 10 m, 20 m, 30 m, and 40 m), at three depths (surface, 10 cm down, and 30 cm down), and at five sampling times over a 3-month period. During this time there was a storm that resulted in significant movement of sand from the beach and high flow of the nearby river, and coincided with increased bacterial load. Within a week the bacterial load had returned to previously measured levels. In general, higher bacterial counts were at the surface level compared with 10 and 30 cm below the surface, and the lower counts were at the low tide mark, with increasing distance from the low tide resulting in increasing bacterial loads, and the highest load at the dune edge. This research provides information about the potential health risk of beach sand and a baseline for future studies exploring the microbial risks of Australian beach sand.