Contamination of Caribbean coastal waters by the antifouling herbicide Irgarol 1051

Irgarol 1051® is a s-triazine herbicide used in popular slime–resistant antifouling paints. It has been shown to be acutely toxic to corals, mangroves and sea grasses, inhibiting photosynthesis at low concentrations (>50 ng l−1). We present the first data describing the occurrence of Irgarol 1051® in coastal waters of the Northeastern Caribbean (Puerto Rico (PR) and the US Virgin Islands (USVI)). Low level contamination of coastal waters by Irgarol 1051® is reported, the herbicide being present in 85% of the 31 sites sampled. It was not detected in water from two oceanic reference sites. In general, Irgarol 1051® was present at concentrations below 100 ng l−1, although far higher concentrations were reported at three locations within Benner Bay, USVI (223–1300 ng l−1). The known toxicity of Irgarol 1051® to corals and sea grasses and our findings of significant contamination of the Northeastern Caribbean marine environment by this herbicide underscore the importance of understanding, more fully, local and regional exposure of reef and sea grass habitats to Irgarol 1051® and, where necessary, implementing actions to ensure adequate protection of these important ecosystems.