MANILA—A dolphin beached in El Nido town, Palawan, died Friday after a garbage bag was jammed in its stomach.

Wally, the juvenile rough-toothed dolphin, was stranded in Nacpan Beach on Thursday morning, according to El Nido Resort's environment department.

"He was weak and emaciated, looking like he had not eaten for weeks. After several attempts at feeding and subsequent release, he succumbed to his illness," it said.

"Post-mortem examination revealed that he had swallowed a plastic garbage bag, which got stuck in his stomach. It was so tightly packed that the bones from the fish it ate after was not even able to pass through."

The advocacy group stressed the need to ban single-use plastics.

"More and more animals are popping up sick or worse, dead from plastic pollution. It is happening so much that it has now become the rule, rather than the exception," it said.

"We can only truly start cleaning up the earth once we eliminate the use of single-use plastics."

Last week, the Philippines and other Southeast Asian nations adopted a joint declaration against plastic pollution during a summit in Bangkok.

• Southeast Asian nations vow to combat plastic debris in oceans

The Philippines, Indonesia, Vietnam and Thailand, along with worst offender China, throw the most plastic waste into oceans, according to a 2015 report co-authored by environmental campaigner Ocean Conservancy.