Coastal areas worldwide are affected by land-based pollutants, including sewage and nutrient runoff, leading to coastal eutrophication, degraded water quality and the impairment of coastal marine ecosystems. Analysis of the clean water indicator, a measurement of the degree of ocean pollution, shows that water quality challenges are widespread, but are most acute in some equatorial zones, especially in parts of Asia, Africa and Central America.
Nearly all countries have room to improve their coastal water quality. Analysis of trends from 2012 to 2018 shows that positive change is indeed possible: 104 of 220 coastal regions improved their coastal water quality over that period. Such improvements require policy commitments at the country level to expand access to wastewater treatment and to reduce chemical and nutrient runoff from agricultural sources, along with global commitments to reduce plastic debris.