MANILA — The Bureau of Fisheries and Aquatic Resources (BFAR) said on Monday the viral videos showing tons of tamban, or herring, in the shores of Sarangani was "natural."

Videos showing Sarangani residents harvesting live tamban as they gather on the shore went viral on social media over the weekend.

This, BFAR said, was likely a result of a phenomenon called upwelling.

"Sa mga ganitong pagkakataon na dumadagsa ang small pelagics kagaya ng tamban, may mga possible reasons. Isa dito ang upwelling, ibig sabihin, yung malamig na temperatura mula sa ilalim ng tubig, pumaibabaw siya, at ito yung nagti-trigger na mai-angat din nutrients sa ilalim ng tubig," said BFAR spokesperson Nazario Briguera.

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"Itong pag-angat ng nutrients na galing sa ilalim ng tubig, mangangahulugan ito ng pagdami ng planktons. Yung planktons ang pagkain ng isda, so hinahabol ng mga isda yung pagkain nila," he added.

Briguera said upwelling incidents are natural especially during the amihan season.

However, he said there were other reasons like beaching.

"Yung beaching, kung saan dumadagsa sa mga baybayin yung isda. Posibleng hinahabol sila ng malalaking isda gaya ng predators, naitataboy sa mas mababaw na parte ng karagatan," he said.

BFAR said the incident showed the abundance of fish stocks in that part of the sea.

Briguera clarified that since the fish were alive, they were safe for consumption of the residents.

"Pwede naman po ito kainin, hanggang sariwa ito. Nakita naman na buhay pa itong dumagsa. Kung may sobra, pwede itong ipreserba, pwede i-dry o lagyan ng asin. Kung may maliit, pwede rin lagyan ng bagoong," he added.

He said the incident had little to no impact to the supply of tamban in the country.