The National Security Council has confirmed that Chinese fishing vessels operating near Ayungin Shoal used cyanide-based chemicals, marking a dangerous escalation in activities within the West Philippine Sea that threatens both marine ecosystems and Filipino naval personnel.
Laboratory analysis conducted by the National Bureau of Investigation's Forensic and Scientific Research Service has conclusively established that yellow bottles seized from Chinese sampans contain cyanide, according to a statement released by NSC spokesperson ADG Cornelio H. Valencia Jr. on April 13, 2026.
The toxic substances were recovered by the Philippine Navy from Chinese vessels operating in the immediate vicinity of BRP Sierra Madre at Ayungin Shoal during two separate incidents in February 2025 and October 24, 2025. The laboratory testing was completed nearly a year after the initial confiscation of the suspicious bottles.
Toxic Chemical Poses Multiple Threats
The NSC statement describes cyanide as "a highly toxic chemical known to cause severe and irreversible damage to humans and marine ecosystems." The presence of this dangerous substance raises serious concerns about the deliberate nature of these destructive fishing practices in Philippine waters.
According to the National Security Council, the use of cyanide represents a form of environmental sabotage designed to eliminate local fish populations that serve as a vital food source for Navy personnel stationed aboard the BRP Sierra Madre. The grounded naval vessel has served as the Philippines' outpost on Ayungin Shoal for decades.
The toxic chemical also poses a direct threat to the coral reef structure surrounding the shoal, which could potentially compromise the foundational stability of the BRP Sierra Madre itself. The NSC warns that severe reef damage could create conditions that Beijing might exploit to fabricate an environmental crisis and deflect attention from its own illegal maritime activities.
Environmental and Legal Violations
The deliberate deployment of cyanide in Philippine waters constitutes multiple violations of domestic and international law, according to the NSC assessment. These actions represent clear breaches of Philippine environmental laws, international maritime norms, and state obligations under the United Nations Convention on the Law of the Sea.
Ayungin Shoal lies well within the Philippines' exclusive economic zone, where the country exercises sovereign rights and jurisdiction over natural resources and maritime activities. The operation of Chinese vessels using hazardous substances in this area is characterized by the NSC as "both irresponsible and unacceptable."
The National Security Council emphasized that these laboratory findings "remove any doubt as to the dangerous and unlawful nature of these activities" conducted by Chinese fishing vessels in the disputed waters.
Government Response and Security Measures
In response to the confirmed cyanide presence, the National Security Council has directed multiple government agencies to strengthen maritime security operations in the West Philippine Sea. The Armed Forces of the Philippines, Philippine Coast Guard, and other relevant agencies have been ordered to heighten maritime domain awareness and strengthen patrol activities.
The directive includes instructions to "take all necessary measures to prevent further environmental harm and safeguard national security interests in the area," according to the official NSC statement. These enhanced security measures represent an escalation in the Philippines' response to Chinese activities in the disputed waters.
The government's response reflects growing concerns about the environmental and security implications of foreign vessels operating with toxic substances in Philippine territorial waters. The presence of cyanide adds a new dimension to ongoing tensions in the South China Sea region.
Strategic Implications for Regional Security
The confirmed use of cyanide by Chinese vessels represents a significant development in the ongoing territorial disputes in the South China Sea. The NSC statement suggests that Beijing has previously attempted to deflect attention from its maritime activities by accusing the BRP Sierra Madre of causing environmental pollution in the shoal area.
The toxic fishing practices threaten not only the immediate marine environment but also the broader ecosystem that supports Filipino fishing communities. The deliberate targeting of fish populations that serve as food sources for naval personnel stationed on the BRP Sierra Madre adds a strategic dimension to these environmental crimes.
The National Security Council warns that damage to the coral reef structure could create conditions for Beijing to manufacture an environmental crisis while simultaneously weakening the physical foundation that supports the Philippine naval outpost.
Firm Government Position on Territorial Rights
The NSC statement concludes with a firm declaration that "the Philippines will not tolerate any act—whether by state or non-state actors—that endangers its personnel or the marine environment, violates its sovereign rights, or undermines peace and stability in the West Philippine Sea."
The government emphasized its commitment to "defending the nation's territory, protecting its natural resources, and upholding the rule of law" in the face of these environmental and security threats. This position reflects the Philippines' broader strategy of asserting its territorial claims while highlighting the environmental consequences of foreign maritime activities.
The confirmation of cyanide use adds scientific evidence to ongoing diplomatic and legal efforts to address Chinese activities in the disputed waters. The laboratory results provide concrete proof of environmental violations that the Philippines can use in international forums and bilateral discussions.
Photo credit: National Security Council