Assessment of anthropogenic chemical pollutants in Bonaire's coastal ecosystems by sediment and PDMS sampling

Anthropogenic chemical pollutants pose a significant threat to coastal ecosystems, including coral reefs and mangroves. In this study, we investigated the presence and potential impact of various pollutants in Bonaire's coastal environments, focusing on sediments and passive samplers to assess the levels of contaminants using GC-MS/MS, LC-MS/MS and ICP-MS. Our research
encompassed a wide range of pollutants, including brominated diphenyl ethers (BDEs), organochlorine pesticides (OCPs), perfluorinated alkylated hydrocarbons (PAHs), poly- and perfluoroalkyl substances (PFASs), polychlorinated biphenyls (PCBs), and metals like cadmium, copper, zinc, nickel, and lead. These pollutants can enter coastal ecosystems through multiple pathways, such as land-based runoff, atmospheric deposition, and sewage outfalls.Sediment samples collected from different locations revealed varying concentrations of these contaminants, with some exceeding threshold values recommended by environmental guidelines. Notably, in the rainy season, PAH levels in the coral reef sediment around a former oil terminal raised concerns, indicating exposure to total PAHs of up 5575,88 ng/g dry weight (dw), as well as metals exceeding effects levels at both the former oil terminal and lagoon adjacent to a landfill up to 232164,86 ng/g dw for zinc and 25752,50 ng/g dw for copper resp. Passive samplers deployedin the dry season showed that pollution persists throughout the year. These results showed higher concentrations of the aforementioned pollutants than European threshold values and worldwide marine environment concentrations in highly-industrialised areas, addressing the issue of pointsource pollution in Small Island Developing States (SIDS) similar to Bonaire.
Overall, this study is the first approach to determine pollutant levels at Bonaire’s coastal ecosystem, which emphasises different potential hotspots and seasons and shows the need for continuous monitoring and fitting measures to reduce terrestrial runoff.