What causes most coastal pollution in the United States?

Most coastal pollution in the United States is primarily caused by runoff from urban and agricultural areas, which carries fertilizers, pesticides, and other contaminants into waterways. Additionally, industrial discharges and sewage overflow contribute significantly to coastal water pollution. Marine debris, particularly plastic waste, also poses a major threat to coastal ecosystems. Climate change further exacerbates these issues by altering weather patterns and increasing the frequency of extreme weather events, leading to more runoff and pollution.