MANILA — The damage from the oil spill in Oriental Mindoro is "extensive" and will be felt for decades, an environmental group warned Thursday.

The motor tanker Princess Empress, which was carrying 800,000 liters of industrial fuel oil, sank near the Verde Island Passage — one of the most biodiverse marine habitats in the planet.

"With this tragedy that has happened, the damage that it will cost to this ecologically sensitive area would be felt for decades," lawyer Rose-Liza Eisma-Osorio, legal and policy director of Oceana Philippines, told ANC's "Headstart".

Mangroves, seagrasses, and corals will take years to recover from the tragedy, she added.

The government's target of cleaning up the spillage in less than 4 months is "unrealistic," Oceana Philippines said.

"I think the realistic would be 6 months to a year," Osorio said, adding that sunken oil will settle in substrate sediments.

• Boom deployed to contain Mindoro oil spill - PCG

President Ferdinand Marcos, Jr. on Wednesday said he hoped cleanup efforts in Oriental Mindoro would be finished in less than 4 months, similar to the 2006 cleanup of the Guimaras oil spill.

In 2006, some 2 million liters of bunker fuel from a sunken tanker off the coast of Guimaras island wreaked havoc in the Panay Gulf and it took the government years to completely address the damage.

"I saw people before sa Guimaras na tinatabo-tabo ang oil with no personal protective equipment and I saw that again in Pola. It’s the same thing sa Guimaras na few days after, there are still no ways to contain the spill," Oceana senior campaign manager Danny Ocampo said.

(I saw people in Guimaras clean up the oil with just water dippers and with no personal protective equipment, and I saw that again in Pola.)

"We salute the government agencies for doing their part but we think there is not enough information for preparedness," he said in an online forum.

Greenpeace campaigner Jefferson Chua, who is from Iloilo, said that while it took 7 years for coastal communities to recover from the Guimaras oil spill, some areas stayed bio-sensitive.

"The recovery was slow and we could expect more long-term rehabilitation. For this oil spill, especially that we don’t have the information on the actual size, it is important for us to know how long our communities will be bearing the brunt of these impacts," he added.

Oriental Mindoro will conduct simultaneous coastal cleanups in various towns from Friday.

The social welfare and labor departments will also implement a cash-for-work program for residents whose livelihoods are affected by the spillage.

Oil has been spotted as far south as Semirara island — which is part of Antique province — more than 130 kilometers from where the tanker went down.

Pola, Oriental Mindoro Mayor Jennifer Cruz has criticized RDC Reield Marine Services, the company that owns the submerged tanker, for allegedly failing to provide immediate assistance.

A company representative, who visited Cruz's office on Wednesday, did not issue a statement to media.

The Philippine Coast Guard has so far collected 200 liters of oil from the sea and 76 drums of oil from coastal areas.

An oil spill boom was deployed on Wednesday after rough seas hampered earlier efforts to contain the slick, Philippine Coast Guard spokesman Armando Balilo said.

Environmentalists warned against the use of dispersants in the cleanup, which they said would only break down oil into smaller particles.

“Dispersants are toxic… They don’t actually make oil disappear… Oil is still left in the area. We need to hear from the government why these specific interventions are being done,” Chua said.

Osorio, meanwhile, said the incident could have been prevented if marine laws were properly implemented.

“The oil spill tragedy should not have happened if preventive measures have been put in place. Oil tankers now should be constructed to reduce the amount of oil spill,” Osorio said.

Mayor Jean Te of Libertad town in neighboring Antique expressed concern about the oil spill's potential effect on the fish supply.

“Tuna season sa area namin so tons of tunas are being caught through sustainable fishing. Nagwo-worry kami at baka mag-shift ang hangin at mapunta sa northern Antique. It has to be [prevented] bago dumating ‘yun,” Te said.

(We are worried that the winds could shift and the oil would reach northern Antique. This has to be prevented before that happens.)

The environment department said Monday that the submerged tanker might have been located.

It was believed to be about 400 meters below the surface, but a remotely operated vehicle would be needed to confirm its exact position.

• Gov't hopes to finish Mindoro oil spill cleanup in under 4 months

HOUSE PROBE

Meanwhile, Oriental Mindoro 2nd District Rep. Aurelio Umali has filed House Resolution 835 which seeks a congressional investigation into the Philippines' maritime laws and safety standards and other related measures.

This is to ensure accountability of sea carriers involved in maritime accidents in connection with the recent oil spill.

"History reveals that from time to time, maritime accidents happen either due to human fault, negligence, unseaworthiness, or due to inclement weather conditions, which result to different kinds of damages, loss of property, and even loss of lives," the resolution said.

"Several accounts and statements of victims of prior sea accidents still call for justice and accountability as they have not received any indemnification from the sea carriers involved in mishap."

Umali said that an investigation and scrutiny of related existing maritime laws, safety standards, and accountability measures are indispensable to ensure protection, public safety, and accountability.

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— With reports from Davinci Maru, Lady Vicencio, and RG Cruz, ABS-CBN News; Agence France-Presse