Filipino troops stationed aboard a dilapidated warship grounded on a contested reef in the West Philippine Sea have seized cyanide from Chinese fishing vessels on multiple occasions since early last year, Philippine officials said Monday, as Manila prepares to lodge a formal diplomatic protest over what it described as deliberate environmental sabotage.
Philippine Navy spokesman Rear Admiral Roy Vincent Trinidad said soldiers confiscated 10 bottles of cyanide from sampan boats — small craft launched from larger Chinese fishing ships — during separate incidents in February, July, and October 2025. Last month, troops observed another Chinese sampan crew dispersing the poison near Ayungin Shoal, and subsequent water tests confirmed cyanide contamination in the area. Trinidad said none of the Filipino personnel aboard the BRP Sierra Madre have tested positive for the substance.
The Sierra Madre, a World War II-era vessel Manila deliberately ran aground on the shoal in 1999 to assert territorial rights, serves as a permanent military outpost on the reef. National Security Council assistant director-general Cornelio Valencia warned that cyanide damage to the surrounding coral could eventually compromise the ship’s structural foundations.
Beyond the threat to the vessel, Valencia said the poisoning put naval personnel at direct risk — through contact with contaminated water, consumption of affected fish, and degradation of the reef ecosystem. “The use of cyanide on Ayungin Shoal is a form of sabotage that seeks to kill local fish populations, depriving Navy personnel of a vital food source,” he said. “These actions also threaten our Navy personnel.”
Both Valencia and Trinidad alleged that the fishing vessels responsible for the poisoning operate under the direction of the Chinese Navy — an accusation Beijing has not formally addressed. Valencia said Manila raised the matter with Chinese officials at a recent bilateral meeting but has received no response. The Chinese embassy did not reply to requests for comment Monday.
The NSC plans to submit a report to the Philippine foreign ministry next week that could form the basis of a diplomatic protest. Manila has also directed its navy and coastguard to intensify patrols around the shoal to contain further environmental damage.
Ayungin Shoal lies within the Spratly Islands chain, near major shipping routes and areas believed to hold significant mineral deposits. China claims nearly the entire South China Sea, a position an international tribunal ruled in 2016 has no legal foundation. The two countries’ maritime dispute has repeatedly turned violent — most recently in a June 2024 confrontation in which Chinese coastguard personnel armed with knives, sticks, and an axe boarded Philippine Navy boats near the same shoal.
