Sewage and Stormwater Outflows

Sewage and stormwater outflows are a top pollution threat, with coastal cities discharging raw or partially treated sewage directly into the ocean. This introduces pathogens, pharmaceuticals, and microplastics that contaminate shellfish beds and bathing waters. Globally, over 80% of wastewater flows untreated, a rate worse than the average for high-income nations, making it a leading source of coastal pollution.