Miles of rocky shoreline and mangrove thickets have been fouled by a fuel spill drifting along Puerto Rico's southwest coast, environmental officials said Friday.
Specialists walked blackened shores as helicopters flew over the area to assess damage and track the slick, which also could threaten a pristine coral reef off the coast of La Parguera, a diving site popular with tourists.
Authorities were still investigating the origin of the spill, which stretched along an estimated eight miles of shoreline from the southwestern town of Guanica to Guayanilla Bay.
"The impact area of this spill has been quite extensive," said Javier Velez Arocho, secretary of the Department of Natural and Environmental Resources, which has closed beaches in the area.
Cleanup crews clad in protective suits and boots walked the shoreline, lugging plastic bags full of oily debris and sand to be trucked away. The workers targeted the most heavily contaminated beaches.
Gov. Anibal Acevedo Vila, who took a helicopter tour of the area with Justice Secretary Roberto Sanchez Ramos, said federal authorities told him the fuel was either dumped by a ship in the Caribbean Sea or emanated from a "local source." He did not give further details.
Capt. James E. Tunstall, commander of U.S. Coast Guard operations in the eastern Caribbean, said five shoreline assessment teams were deployed to determine the nature and extent of the contamination.
"Every effort will be made to conduct safe and effective recovery operations," he said.
So far, U.S. Fish & Wildlife Service personnel had not received any reports of birds or fish being killed by the spill.
Investigators were inspecting three ships anchored in Guayanilla Bay and questioning their owners to try to discover the origin of the fuel — believed to be bunker oil, used to power older vessels.
In a statement, the Coast Guard said the federal Oil Spill Liability Trust Fund, into which oil companies must pay to cover the costs of spills, has been tapped for containment and recovery operations in the U.S. Caribbean territory.
An investigation is under way to identify a responsible party that could be liable for up to three times the cost of cleanup, according to the Coast Guard.
Velez estimated that the cleanup would take several weeks.