Linking Shores: Defending non-disputed waters and West Philippine Sea claims

Nine years after the Arbitral Tribunal’s ruling in its favor, the Philippines continues to face Chinese harassment in the West Philippine Sea (WPS) and, without an international enforcement mechanism, must act to protect its maritime boundaries.

Under President Ferdinand Marcos, Jr., the Philippine government has continued to strengthen maritime security institutions to protect waters within our maritime zone. The Maritime Zones Act defines our entitlements and sovereign rights or jurisdiction over our maritime zone, including the territorial seas, contiguous zone, 200-mile Exclusive Economic Zone (EEZ), and the waters surrounding, within, and adjacent to the Kalayaan Island Group and Bajo de Masinloc (Scarborough Shoal). This institution plays a crucial role in operationalizing the arbitral ruling in the South China Sea, providing a concrete mechanism to safeguard our EEZ.

The EEZ, a vast body of water with significant economic value, must be safeguarded from threats, including China’s continued reclamation within the Philippine EEZ over the years. China’s provocative actions — such as ramming a Philippine naval vessel on a resupply mission to the grounded BRP Sierra Madre at Ayungin Shoal in the WPS, 124 miles from Palawan, and a symbol of the nation’s sovereign claims — highlight the serious challenges confronting Philippine maritime law enforcement and security. This year, the Philippine Coast Guard (PCG) also reported the presence of two Chinese research vessels operating within the EEZ without the consent of the Philippine government.

China’s gray zone actions have been concentrated in the western flank of the Philippines. However, with its long-standing interests in the Pacific seaboard, Chinese vessels have recently been sighted in the waters of the Philippine Rise — a 13-mile underwater plateau in the eastern flank that forms part of the Philippine continental shelf — prompting renewed calls to secure these waters. BBM described this as “a bit of an escalation” and a “clear intrusion,” which led to the deployment of a PCG vessel to carry out law enforcement operations. The Philippine Navy has also mounted a response.

This shift in Chinese activity toward the eastern flank underscores that the threat to the Philippine Rise is not limited to illegal incursions — a clear violation of territorial rights — but extends to the potential harm these encroachments pose to biodiversity and the marine environment. The Philippines holds sovereign rights over the Benham Rise, particularly in the exploration and exploitation of its rich and diverse resources, which include potential oil, gas, and minerals in the seabed, as well as abundant fisheries and tuna fishing grounds — critical for both food and energy security. As Justice Antonio Carpio has emphasized, this means the Philippines alone has priority and exclusive rights to its utilization.

Recognizing these stakes, calls to protect the Benham Rise intensified about eight years ago. In 2017, fisheries expert Dr. Jose Ingles described its conservation as “critical” to the nation and the long-term sustainability of oceanic tuna stocks. The Philippine Rise provides vital ecosystem services — regulating climate change, serving as a tuna habitat, and supporting livelihoods, food security, and recreation. In 2018, Silliman University President Ben Malayang urged science-based decision-making for its development, while Justice Carpio stressed that China should not be allowed to conduct marine scientific research unless it recognizes the 2016 arbitral ruling. That year also saw the creation of the Philippine Rise Marine Resource Reserve, a protected food supply exclusive zone. For fishers from Isabela, Aurora, Catanduanes, and parts of Bicol, it is their “food basket.”

It is noteworthy that the Philippine Rise is not part of the disputed WPS. The WPS accounts for only about a third of the country’s maritime domain, underscoring the vast extent and breadth of the Philippines’ maritime security and law enforcement responsibilities. This perspective highlights a broader imperative: to address — and, where necessary, prioritize — the connection between protecting and defending non-disputed waters and upholding the country’s WPS claims, while effectively integrating environmental stewardship with archipelagic defense.

As this clarifies the evolving threat picture for the Philippines, it becomes essential to reassess the defense and protection of the Pacific seaboard. At present, we are witnessing two-pronged efforts from various actors. On one front, the PCG in 2021 installed state-of-the-art buoys — tangible evidence of the government’s commitment to advance the Philippine Rise as a protected zone against mining and oil exploration. In 2022, Senator Risa Hontiveros filed Senate Bill No. 146, seeking to declare a portion of the Philippine Rise a protected area and to establish a Philippine Rise Marine Resource Reserve Management Board tasked with enforcing measures against illegal fishing, resource depletion, and unlawful intrusion. On the other front, in the area of archipelagic defense, a naval port in Aurora province and the enhancement of Aurora’s port capabilities now serve as a springboard for sustaining maritime presence in the Philippine Rise.

Together, these initiatives demonstrate a coordinated approach that reinforces both environmental stewardship and strategic defense across the Philippines’ maritime domain.

Alma Maria O. Salvador, PhD, is an associate professor of Political Science at Ateneo de Manila University.