MANILA - The Philippines, Vietnam and China should set rules on common fishing in Scarborough Shoal, Acting Chief Justice Antonio Carpio said Wednesday.

"You cannot just overfish there because you have to have sustainable fishing. We must have rules and we should go to the tribunal, ask that China and Vietnam sit down with us to draft the rules there," he told ANC's Headstart.

The arbitral tribunal, in its 2012 decision, ruled that the lagoon and territorial sea around the shoal was the "common fishing ground" for the three countries, he said.

With Filipinos barred from the lagoon, Carpio said Manila should ask the tribunal to order Beijing to allow its fishermen in and also file a diplomatic protest on this.

"Our fishermen are not allowed to go inside the lagoon and I understand Chinese fishermen are allowed to enter the lagoon. There’s discrimination. We should protest that and ask tribunal to order China to allow Filipino fishermen," he said.

• China still rules over Scarborough Shoal, say Filipino fishermen

Filipino fishermen earlier complained that Chinese coast guard personnel would seize their catch, often worth thousands of pesos, in exchange for a few pieces of bottled water, packs of cigarettes, and instant noodles.

President Rodrigo Duterte said the exchange was a form of “barter” and it was unfortunate that the Chinese and Filipinos had a problem in determining the value of the catch and the items they gave in return.

• Duterte on bullying of Filipinos in Scarborough: It was barter, not outright seizure

Chinese Ambassador to the Philippines Zhao Jianhua said the coast guard personnel involved in the incident will be disciplined “in accordance with our own regulations.”

• Chinese envoy vows action on harassment of Filipino fishermen

Malacañang also said Duterte may raise the issue with Chinese President Xi Jinping.