The latest maritime domain awareness flight of the Philippine Coast Guard confirmed a "slight" decrease in the number of Chinese ships in the West Philippine Sea.
This came after the agency intensified its patrols in the area and documented the aggressive actions of China in the strategic waterway since February.
The number of Chinese maritime militia spotted within the territorial sea of Pag-asa Island decreased to 15 from 42 in less than a week.
However, a China Coast Guard vessel and a People's Liberation Army (PLA) Navy's Jiangdao-class ship continue to loiter within Pag-asa's 12-nautical mile territorial sea.
While Chinese maritime militia ships were not spotted at the Ayungin Shoal, the China Coast Guard maintained its presence roughly six nautical miles from the Philippine Navy ship BRP Sierra Madre.
The number pf Chinese maritime militia vessels also decreased at Sabina Shoal to 17 from 26 two weeks ago.
Dr. Jeffrey Ordaniel, Maritime Security Director for the Pacific Forum, said the country Philippines should assert its domain despite the decreased presence of Chinese vessels in the West Philippine Sea.
Ordaniel said that the mere presence of the Chinese government vessels is a "form of harassment."
“Form of harassment siya kasi vina-violate niya 'yung ating sovereign right in our EEZ. Dine-deprive niya yung ating pangingisda na mangisda sa sarili nating dagat,” Ordaniel said.
On March 9, an aircraft of the Philippine Coast Guard conducted a maritime domain Awareness flight over the West Philippine Sea. With five journalists on board, the Philippine aircraft received seven radio challenges from the China Coast Guard - four times as it entered the territorial sea of the Pag-asa Island (Thitu Island) and three times at the Ayungin Shoal (Second Thomas Shoal).
The Chinese vessels fell squarely within Pag-asa Island's 12 nautical mile territorial sea. A China Coast Guard has lingered at Ayungin Shoal or within the Philippines' Exclusive Economic Zone (EEZ).
"You are entering the (inaudible) China air space," the China Coast Guard radio messages said. "Leave immediately... to avoid any misunderstanding."
In anticipation of the radio challenges, the Philippine Coast Guard has ready response.
"Calling China Coast Guard. You are transiting inside the Philippine territorial sea of Pag-asa island. Identify yourself and state your intention to prevent misunderstanding."
The Philippine Coast Guard reported that the Chinese vessels remain anchored in the contested waters, but no fishing activities are monitored.
“Dahil ba hindi kumikilos ang mga militia vessels, dahil hindi sila nangingisda ay hahayaan natin sila? First step lang yan (ng China)," Ordaniel said. "Papasok ang China Coast Guard. Papasok ang PLA Navy tapos mahirap na sila paalisin diyan.”
“Kung ikaw ay mangingisda with the presence of big fishing vessels of China and big government vessels of China ay hindi ka na makakapangisda diyan,” Ordaniel added.
He explained that lingering Chinese vessels in the West Philippine Sea is a "gray zone" tactic.
"Gray zone is a gray zone operations para siyang series of activities. You can imagine ang black and white spectrum. Black zone - those activities considered attack or invasion or use of force or giyera. On the other end of the spectrum, you have the white zone activities. These are activities that are peaceful. For example, exercise of innocent passage. If you are a warship, you pass through another state's territorial sea exercising innocent passage rite under UNCLOS, that is white zone activity," Ordaniel explained.
The Philippine Coast Guard said it will continue to publicize all incidents of Chinese incursions in the West Philippine Sea amid Beijing's aggressive actions in the strategic waterway.
The agency also assigned Commodore Jay Tarriela as the spokesperson on West Philippine Sea matters. Tarriela is a commissioned officer of the Philippine Coast Guard.
The Philippine Coast Guard, under the Department of Transportation, believes in the importance of exposing incidents of China's "bullying" in the West Philippine Sea to counter the Chinese "gray zone" strategy.
The National Task Force-West Philippine Sea members will vet the information the Philippine Coast Guard will release to the public.
In 2016, the Philippines created the NTF-WPS to coordinate its policy on the West Philippine Sea amid the rising tensions with China. National Security Advisor Secretary Eduardo Año leads NTF-WPS with undersecretaries from fifteen government agencies - including foreign affairs, national defense, environment and natural resources, energy, trade and industry, transportation and communications, the military, the police and fisheries and aquatic resources.