Distribution,sources and fates of floating oil residues in the Eastern Gulf of Mexico

Pelagic tar was monitored over a two-year period in the Eastern Gulf of Mexico. A total of 416 surface and subsurface samples were collected during monthly cruises. Concentrations of pelagic tar found in the Eastern Gulf of Mexico were substantially higher than values reported for other areas around the world. Tar is primarily associated with the Gulf Loop Current, whereas continental shelf areas are relatively uncontaminated. Grounding of significant amounts of tar occurs primarily along the south-east coast of Florida, between Key West and Fort Pierce. Approximately 10–50% of the tar in the eastern Gulf is transported in from the Caribbean Sea via the Yucatan Straits. The remainder originates within the Gulf. Approximately half of the pelagic tar samples collected during the study appeared to have originated from tanker operations.