About half of the global population resides within 150 km of an ocean (1). As urbanization and demographic shifts toward coasts have increased, untreated and inadequately treated sewage has polluted ocean and coastal waters (2). Sewage introduces harmful substances to marine ecosystems, including nutrients, pathogens, heavy metals, microplastics, and organic compounds, posing grave risks to these delicate environments (3). The international community must work together to mitigate the impact of sewage pollution, including in developing countries where resources are limited.
