MANILA - China is responsible for most of the destruction in the West Philippine Sea, an American scientist told House lawmakers Tuesday.

Marine biologist Dr. Kent Carpenter of US-based Old Dominion University told House members that China alone accounts for most of the destruction in the disputed waters.

“If you look at the total damage that's done so far, China is not the only country that has building activity on these islands on these reef flats on the West Philippine Sea. Vietnam does, the Philippines does, and Malaysia also has some activity out here," Carpenter said.

"But the bulk of the damage is being done by the People’s Republic of China, as 14 square kilometers (sq. km) were destroyed by (its) island-building activities."

The American scientist said about 104 sq. km of reefs in the disputed waters were destroyed by China’s activities.

He said Beijing's activities in the West Philippine Sea slowed down in the immediate aftermath of the ruling in 2016, when the Permanent Court of Arbitration (PCA) in The Hague upheld Manila’s sovereign rights to its 200-nautical-mile exclusive economic zone (EEZ), rejecting Beijing’s historic claim to resources in the South China Sea using its nine-dash line doctrine.

“After the court ruling, there was actually some push-off by (Beijing). After the tribunal came down and judged against them, there appeared to be some reluctance for them to continue their destructive methods,” said Carpenter, who testified for Manila in the famous Philippines vs China case in the Hague.

China, however, resumed its "destructive" fishing activities in 2018.

“We now have evidence in 2018 in Scarborough Shoal showing that they have started to extract again tridacna from the reef flats of different parts of the South China Sea," the scientist said.

He added: “We also have more satellite imagery in 2018 that shows the sediments continued to bleed away from these islands. We assume it will take decades, if not centuries, for coral reefs to be re-established in the islands that were destroyed.”

Carpenter urged Manila to keep up the diplomatic pressure against China as he noted that the destruction has come to the detriment of Philippine fishermen.

”One of the things that we have to worry about because of the destruction that was done in the West Philippine Sea, is that the amount of resources available for the Philippines has actually diminished and there's some actual evidence for this.”

Bayan Muna Rep. Carlos Zarate blamed this on the government's lack of action.

“I don't know that there will be a change in the policy of the current administration," he said.

Unlike the Aquino administration which filed the PCA case, the Duterte administration has pursued friendlier relations with China despite criticism over Beijing’s activities in the West Philippine Sea.

- Report from RG Cruz, ABS-CBN News