Jakarta Bay (Indonesian: Teluk Jakarta) is a bay north of North Jakarta city. The Thousand Islands are located in Jakarta Bay. 13 rivers flow into the bay. The majority of the bay's coastal communities consist of people living below the poverty line, in conditions of poor sanitation. Nutrient inputs from agricultural runoff, industrial pollution, and wastewater have led to eutrophication, which in turn led to changes in the area's biodiversity. Harmful algal blooms have been observed.