The oil tanker MT Princess Empress carrying 800,000 liters of industrial fuel started sinking offshore of Naujan, Oriental Mindoro on the 28th of February at 4:16 AM. The 20 men aboard were rescued soon after but by March 1, 2023 the ship was declared fully submerged following aerial and seaborne survey (NDRRMC SitRep No. 1). Following this, an oil sheen was also seen near the waters of Oriental Mindoro.
By March 5, oil slick sightings in Quiniluban and Agutaya, Palawan were sighted. Coastal clean-up and protection groups were collecting oil waste not just in MIMAROPA Islands but also in Antique of Panay Island (NDRRMC SitRep No. 7). Within the following days, the possible sink site and source of the oil spill were investigated. BRP Hydrographer Ventura deployed multibeam echo sounders and survey equipment which had pinpointed a possible location but, due to unfavorable sea conditions, had to turn back to port. A remotely operated vehicle (ROV) was needed for complete visualization (NDRRMC SitRep No. 8).
During this first week, the Department of Environment and Natural Resources (DENR) estimated that 21 marine protected areas could be affected. These include seagrass beds, mangroves, and pathways for fish larvae that are important for the growth and reproduction of marine life forms.
By March 18, a total of 6603 liters of oily water from offshore operations, 1276 sacks of oil-contaminated debris, and 113 drums of waste from shoreline clean-up had been collected in MIMAROPA alone. For Antique, a total of 3500 liters of oil water were collected along with 20 drums of oil-contaminated debris, 518 sacks of oily sea grass, and 8-ton bags of oil-contaminated garbage (NDRRMC SitRep No . 15).
Two days after (March 20), the Japanese salvage vessel Shin Nichi Maru deployed a remotely operated vehicle. Unfortunately on the same day, oil slicks were observed near the waters of Verde Island Passage (VIP) (NDRRMC SitRep No. 20).
The Philippines had been previously quantified as the Center of Marine Biodiversity with the Verde Island Passage being called “The Center of the Center of Marine Biodiversity”. Boasting one of the highest diversities of shore fishes, VIP has both global biological significance as well as local economic importance.
The actual location of the sunken vehicle had been pinpointed by the ROV the following day (March 21). By the 27th of March, a total of 172,928 people within 166 barangays in MIMAROPA, Regions VI, and CALABARZON had been affected by the incident (NDRRMC SitRep No. 24).
By the 17th of June, nearly four months after the sinking of MT Princess Empress the Philippine Coast Guard had announced the completion of their oil spill removal and recovery operations from all the eight cargo tanks of the vessel.
Oil Spill Detection using Remote Sensing
The UP-Resilience Institute- NOAH Hazard Assessment team has been using satellite images from Sentinel 1 of the European Space Agency (ESA) to monitor and delineate the possible oil spill traces for the months of March to June (Figure 2). In this monitoring study, remote sensing techniques play a vital role in assessment and response. The analyzed timely data was forwarded to the Coastal Defense Regiment of Philippine Marine Corps (CDR PMC) upon their request. This detection method is usable in quick response and long-term monitoring for concerned agencies and stakeholders.
From the first images, the possible oil spill trace could be seen originating around 14 km offshore of Naujan (121.529°, 13.321°). It seems that the widest spread of oil slicks occurred between the last week of March to early May. Even during the first week of June, upon which the removal of the remaining oil from the submerged tanks was almost complete, there were still oil spills detected on the surface of the ocean.
Unfortunately, even with the complete removal of the remaining oil from the submerged vessel,the irreversible impacts of the disaster have already occurred. Both humans and the environment will take time to recover from this disaster. The environmental damage due to the oil spill has been estimated to be around P7 billion. According to the National Disaster Risk Reduction and Management Council, the livelihood of 27,850 farmers and fisherfolk had been affected by the incident. The production loss/cost of damage to agriculture amounted to P4.9 billion (NDRRMC SitRep No. 131).