At about 1pm Thursday, Department of Environment launched an investigation into a report of an oil slick.
The slick, estimated to be 150 feet in diameter, was spotted by an aircraft about one to two miles off the Royal Palms area on the west coast of Grand Cayman.
DoE asked Chief Marine Enforcement Officer Mark Orr to investigate; Mr Orr put two boats into the sea to search for the slick.
After about 40 minutes of searching, Mr Orr discovered traces of oil approximately two miles off Public Beach, which appeared to be the remnants of a small diesel spill. The slick was about 10 feet by 30 feet and was rainbow sheen colour, indicating that the slick was very thin.
Continuing the search, Mr Orr found two additional traces of diesel approximately 2.5 miles west northwest of Public Beach. Both slicks were smaller and quite thin. The CMEO reported to the department that all of the slicks were being pushed away from shore and would not impact the coast.
DoE says that there will be no attempt at a clean-up since the slicks are too thin to be recovered. Investigations will continue to learn the source of the spill.
Light distilled oils such as diesel and gasoline are more toxic than heavier oils; however they are often quickly broken up by evaporation and by dispersion from wave energy.
Once an oil slick reaches a thin rainbow sheen colour it has lost much of its adhesion and is nearly impossible to recover with sorbent pads or skimmers.
DOE has the equipment to chemically disperse oil, but this is never used for light distilled products such as diesel.