The Subic oil spill comes as the Philippines reels from its worst-ever oil spill off Guimaras island.
Authorities have yet to establish the source of the Subic oil slick since there are no reports of leaking vessels in the area.
Olongapo City Mayor James "Bong" Gordon ordered a massive cleanup to contain the oil spill, sludge fragments of which washed up on the coastline of Barangay Barretto here.
Gordon sought the assistance of the Subic Bay Metropolitan Authority (SBMA) to track down the source of the slick on the possibility that it might have "foolishly" dislodged used bunker oil.
Authorities also did not discount the possibility that a passing vessel could have dumped the used oil.
"We’re still trying to identify the ship," Gordon said. "We called the Maritime Police to trace it."
A report submitted by Capt. Perfecto Pascual, SBMA Seaport Department manager, to SBMA deputy administrator for operations chief general Jose Calimlim, the oil spill was initially sighted by the harbor patrol of the SBMA Law Enforcement Department last Thursday morning.
"Since our oil spill equipment was borrowed by the Philippine Coast Guard to be used at Guimaras Island, we sought the assistance of the Coastal Petroleum company in the freeport to help us in containing the spill," Pascual said.
He added that the spill "appeared to be sludge oil pumped out from the bilge of any passing vessel."
Pascual said the Coastal Petroleum personnel found out that the spill is petroleum-based and can be treated with chemical dispersants.
There were initial reports that fishermen found hundreds of plastic bags containing used oil floating in Subic Bay.
A certain Arthur Vega of Barangay Barretto said he found a plastic bag full of waste oil floating near the shoreline of Zuzuki Beach Resort.
"Parang sinadya yung pagkakatapon ng langis, yung iba naka-plastic bag malayo ka p alang naamoy mo na yung langis na tumapon sa dagat," Vega said, suggesting the spill may have been deliberate.
Olongapo spokesman Vic Vizcocho Jr. said five kilometers of coastline have been hit, affecting at least seven beach resorts.
The garbage bags, containing what may be used bunker oil, appeared to have been deliberately dumped and were ruptured by waves, he added.
"Mayor Gordon said we will make them pay for the damage," Vizcocho said. "We don’t know yet what will be the damage to marine life, to business."
Subic Bay Tourism Resorts Association president Carlito Baloy added the oil appeared to have leaked out from the plastic bags.
The heavy rains Thursday night could have washed the oil bags ashore, rupturing some of them and spilling their contents on the beaches, Baloy said.
"Most of the beaches are not suited for swimming and water sports activities for tourists," he said.
Baloy ordered the temporary closure of beaches to the public.
He said 44 beach resorts stand to lose about P3.4 million in revenues over the weekend due to the oil slick.
Among those affected are the Baloy Beach Hotel, White Rock Resort Hotel, Ocean Adventure, Green View Resort, By the Sea Resort, Suzuki Beach Resort, Driftwood Beach, and the Arizona Beach.
Baloy added several business establishments, particularly hotel operators in the area, complained of the foul odor and messy sludge in the beaches, forcing them to check out or cancel their reservations.
"We have already received cancellations of room reservations," said Ramon del Rosario, owner of the By the Sea Resort Hotel.
This city is near the former US-run Subic Naval base that has been transformed into a freeport and special economic zone.
Beach resorts in the city remain popular among Americans and Western tourists.
Sen. Richard Gordon, meanwhile, said the Philippine Coast Guard should be blamed for its negligence in ensuring protection of the marine resources off Subic Bay.
Gordon also urged the SBMA to implement damage-control measures to protect the Ocean Adventure Park and save several whales and dolphins from possible poisoning because of the oil spill.
The former SBMA chairman also called on Coast Guard Commander Arthur Gosingan to conduct an immediate investigation on the oil spill.
Gordon said Gosingan should focus on the ships currently anchored near the Grande Island at Subic Bay Freeport on the possibility that one of the vessels might have dumped the oil in the bay area.
Ironically, the oil spill occurred just after the SBMA deployed its high-tech oil spill equipment to help clean up the oil mess in Guimaras.
The SBMA provided the specialized oil spill mitigating equipment to the Philippine Coast Guard-Oil Spill Response Team, which was shipped out over the weekend to be used in the cleanup efforts along the Guimaras coastline.
Specialized equipment, which included oil skimmers, industrial grade hoses, oil booms, suction engines and an air blower, were loaned out to the PCG in the effort to clean up the oil mess and avoid more damage to the surrounding ecosystems in Guimaras.
With the oil spill in Subic, the SBMA is retrieving the equipment to be used in addressing its own oil spill incident. - With Ric Sapnu, AP