Scientists and fisherfolk are calling for the immediate closure of an ethanol plant in Bais City, citing indications that it continues to discharge wastewater into a marine protected area.

Marine scientists from Silliman University said Bais Bay continues to suffer ecological degradation nine months after a containment lagoon operated by Universal Robina Corporation-Sugar and Renewables (URC-SURE) spilled large volumes of ethanol wastewater into the Tañon Strait.

Recent field assessments conducted by Silliman University's Institute of Environmental and Marine Sciences (IEMS) and the Angelo King Center for Research and Environmental Management (SUAKCREM) found that up to 69 percent of total coral cover in the surveyed reef areas had recently died, which researchers said indicates the continued discharge of wastewater into the Tañon Strait.

The findings were presented during an online forum co-organized by Oceana and Oceanus Conservation.

According to the report, the prolonged discharge of vinasse, a high-organic-load byproduct of ethanol production, has contributed to the declining health of Bais Bay's benthic habitats.

Dr. Aileen Maypa, who led the ecological assessment team, presented habitat damage and water quality findings, including photo documentation showing recently dead coral colonies and deteriorating seagrass beds in northern Bais Bay.

She said the wastewater has fueled eutrophication, which promotes algal blooms that compete with marine life for dissolved oxygen.

"If the spill is not halted, the organic matter from the wastewater spill will continue to feed the algal bloom. These algae and phytoplankton compete for the oxygen in the water that corals, seagrass and fish should be getting," Maypa said, referring to the possible cause of a recent fish kill.

She added that the dark-colored water and algal blooms also block sunlight needed by seagrasses and corals for photosynthesis, raising the risk of ecosystem collapse.

"Restoration efforts will be futile unless the source of the spill is plugged now," Maypa said.

The major wastewater spill occurred from 24 to 26 October 2025, when earthquake-induced cracks and heavy rains caused the retaining wall of URC-SURE's 20-hectare wastewater lagoon to collapse, releasing an estimated 255,000 cubic meters of molasses-based wastewater into North Bais Bay within the Tañon Strait Protected Seascape.

URC-SURE earlier said it had repaired the collapsed dike and reinforced the structure with boulders and rubber tires.

However, Ricardo Aguilar, president of the Fisherfolk Association of Manjuyod-Bais, claimed residents continue to observe wastewater flowing through the plant's drainage canals into the sea despite the company's assurances that the discharge had stopped.

"Pagkatapos ng October 2025, sabi nila, wala nang dumaan na waste. Pero nakita namin sa gilid ng highway, papunta sa may Taytay sa Alangilanan, doon sa canal, derecho sa sapa, derecho sa dagat. Palagi namang nagle-leak ang lagoon nila. Mag-high tide o low tide, magpula ang tubig, derecho 'yan sa dagat," Aguilar said.

Maypa said another fish kill reported in May may have been linked to another wastewater discharge.

"If there was a fish kill again, then there must have been another spill," she said.

Oceana Senior Director for Campaigns and Policy Rose-Liza Eisma-Osorio said the local government and the Department of Environment and Natural Resources have an obligation to stop the discharge immediately because of its impact on food security and the livelihoods of coastal communities.

Bais City representative Daisy Marie Gesim said the city government is coordinating with the Tañon Strait Protected Seascape (TSPS) Management Body to enforce the closure of the ethanol plant's lagoon.

TSPS representative Atty. Chad Ian Rubio said halting the wastewater discharge will require the passage of a resolution by the Protected Area Management Board of the Tañon Strait Protected Seascape.