WILLEMSTAD – A major scientific study of Curaçao’s coastal waters has identified 1,394 different human-related chemical substances originating from land, with researchers concluding that the pollution is not limited to individual discharge points but has spread around the island.
The research, published in Environmental Science & Technology in June 2026, represents the first island-wide, multi-season assessment of these so-called xenobiotics along Curaçao’s coastline. Researchers examined substances associated with pharmaceuticals, pesticides, personal care products, plastics, industrial activity and other human sources.
Scientists initially detected approximately 30,000 different molecular features in water samples. After applying strict criteria to distinguish substances originating on land from naturally occurring marine compounds, they identified 1,394 xenobiotics that were significantly more abundant in terrestrial water and decreased farther offshore.
The researchers collected 115 nearshore samples at 17 locations around Curaçao during three sampling campaigns in 2021 and 2022. The sites included Directeurs Baai, Caracas Baai, Mambo Beach, Marie Pampoen, Nieuw Nederland, Punda Beach, Piscadera Beach, Boka Sami, Playa Porto Marie, Daaibooi, Playa Lagun, Kleine Knip and Playa Kalki, among others. The research also included terrestrial and offshore samples for comparison.
The study found a clear connection between the substances detected in coastal waters and material originating on land. The researchers used fluorescent dissolved organic matter as an indicator of terrestrial inputs and found a significant relationship with the selected xenobiotics.
Pollutants can reach the sea through several routes, including surface runoff, wastewater discharge and underground groundwater flows. Heavy rainfall can increase those flows and transport greater quantities of contaminants toward the coast.
Of particular concern is the researchers’ conclusion that chemical contamination cannot simply be considered a problem near known wastewater outlets or heavily developed coastal areas.
The study found that contaminants can be transported considerable distances by Curaçao’s coastal currents. In some cases, concentrations away from their apparent source were even higher than those measured closer to where they entered the marine environment.
According to the researchers, this means chemical pollution potentially affects Curaçao’s wider marine ecosystem rather than only reefs immediately adjacent to discharge locations.
The findings are particularly relevant for coral reefs. Previous scientific research cited in the study shows that xenobiotics can affect growth, reproduction and resistance to environmental stress in marine organisms. Mixtures of pollutants can also have more complicated and potentially greater ecological effects than individual chemicals.
The researchers say the Curaçao study establishes an important baseline that can now be used for future water-quality monitoring and management.
They also argue that strategies to protect coral reefs should take into account not only where pollution enters the sea, but also how currents, rainfall and connections between land and sea redistribute those contaminants around the island.