Regular visitors and locals have reported a rise in the number of face masks and PPE shields being collected from the seabed.
"It might be because some people who get on the boat just loop their masks on one end and it comes off, or others just do not throw them away properly," said Arnel Vergara, a Filipino professional diver who has been diving in the area for the past decade.
Carmela Sevilla, a resort owner and diving instructor, said the masks were adding to plastic bags, sachets, diapers and packaging materials that plague local waters during the monsoon season.
"I think we'll be seeing more of the face masks," said Sevilla. "I think we'll be wearing face masks for a while."
Girro Maranan, an official at the Batangas tourism office, said officials were aware of the issue and spearheading clean-up drives.
"Our marine diversity is the most affected," Maranan said.
Marian Ledesma, a campaigner for Greenpeace in the Philippines, said poor management of the country's waste disposal strategy had led to rubbish accumulating in its tributaries. - Reuters