2026/07/21 by D. Abigail Renegar, Richard E. Dodge, Anthony H. Knap +17
Environmental Science · Biochemistry, Genetics and Molecular Biology · #Oil Spill Detection and Mitigation #Toxic Organic Pollutants Impact #Biological Research and Disease Studies
paper · doi:10.1016/j.marpolbul.2026.120095
The TRopical Oil Pollution Investigations in Coastal Systems (TROPICS) study, initiated in 1984 on the Caribbean coast of Panama, sought to evaluate the comparative impacts of untreated crude oil versus chemically treated (dispersed) crude oil on nearshore tropical marine communities. The results broadly established that the impacts to mangrove communities from non-dispersed crude oil included significant adult tree loss, with long-term implications for substrate stability. Dispersed oil caused less impact to the mangroves, but resulted in significant short-term effects on coral cover and seagrass invertebrate communities, both of which recovered to pre-exposure levels within 10 years. The 2024 research expedition to the TROPICS locations replicated key biological assessment methodologies from the original and 10-year studies and introduced expanded chemical analyses of sediment samples. After four decades of assessment at the TROPICS sites, the overall conclusion that dispersant use improved the overall outcome for the mangrove forest remains clear, with long-term trends in coral cover possibly related to broader ecological changes rather than lingering treatment effects. Chemical analyses from sediment cores collected inside the sites highlighted the presence of biogenic hydrocarbons, alkanes, and PAHs in all samples across sites, depths, and tidal areas. No petroleum biomarkers of the original test oil were detected in any of the core samples collected; sediments both within the original test sites and immediately adjacent to the sites appear to be no longer contaminated with oil and dispersed oil, although implications for long-term carbon storage in these environments after disturbances with variable recovery trajectories may be significant.