MANILA, Philippines - Fishermen in San Miguel Bay in Mercedes, Camarines Norte got the surprise of their lives Sunday after the provincial tourism office and Bantay-Dagat sighted a butanding or whale shark in San Miguel's waters.

Juanito Barrantes, operations officer of Bantay-Dagat Mercedes, said the whale shark could have been attracted to rich feeding grounds in the area.

"I think the whale shark appeared because we've removed 75% of illegal fishing in Mercedes. There's also a lot of plankton in the area," he said.

Most whale sharks in the Philippines are sighted in Donsol, Sorsogon.

The Bureau of Fisheries and Aquatic Resources, meanwhile, denied that the threat of a tsunami brought the whale shark to Mercedes.

Director Dennis del Socorro of BFAR-Bicol said whale shark sightings could increase in Camarines Norte as the El Niño warms up coastal waters in the province.

He also warned fishermen not to catch whale sharks, which are considered a protected species.