He cited DFA confirmation that China did not seek Philippine consent for the Tan Suo Yi Hao expedition, whose vessel reportedly dived and went dark on AIS while ignoring PCG radio challenges.

Tarriela said Hubo Reef, Escoda Shoal, and Katimugan Bank cannot form basis for territorial or maritime claims that override the Philippines’ UNCLOS rights.

The Philippine Coast Guard spokesperson rebutted China’s sovereignty claims over waters near these features, arguing international law protects the Philippines’ rights and permits marine scientific research under consent rules.

Tarriela called for transparent, law-based scientific research and said China could seek consent if its activities are lawful and peaceful.

He noted seabed data collected without consent has resource and military significance, underscoring why UNCLOS consent requirements matter to coastal states.

Tarriela argued China’s domestic laws cannot override international obligations, noting Beijing ratified UNCLOS in 1996.

He challenged China’s description of routine patrols, saying the presence of warships around a research vessel looked like escorting rather than routine protection, and that lawful research does not require naval protection.

Tarriela said China’s claimed sovereign rights rely on the Nine-Dash Line, which an arbitral tribunal found to be contrary to UNCLOS or without lawful effect beyond China’s entitlements.

The exchange occurs amid ongoing Manila-Beijing tensions over South China Sea claims, with the Philippines continuing to invoke the 2016 arbitral award and UNCLOS despite China’s rejection.

Under UNCLOS, coastal states must consent to marine scientific research within another state’s EEZ; Tarriela cited Articles 246, 248, and 253 to support the Philippines’ rights and possible suspension of research lacking proper consent.

Tarriela asserted that Spratly Islands cannot be treated as a single archipelagic unit to claim surrounding waters, referencing the 2016 arbitral award which rejected archipelagic baselines around the Spratlys and denied exclusive EEZ or continental shelf rights from high-tide features.