Hundreds of thousands of milk fish washed up dead at Taal Lake in Talisay, Batangas, south of Manila on Sunday, baffling environmentalists and raising concerns over climate change issues.

About 500 metric tons (500,000 kilos) of fish, worth more than 50 million pesos (U.S. $ 1.159 million) were seen floating in the water in the six towns of Batangas province the past two days, a local mayor told Reuters.

According to a local town agriculturist, the cause of the fish kill was a sudden climate change in the area.

The common perception of fish death is linked to depletion of oxygen in water, which is caused due to a number of factors. Gases released from volcanic activities often lead to poor oxygen levels in nearby lakes, but scientists believe that the deaths are not related to activitities inside Taal volano, which is surrounded by the Taal Lake.

However, they didn't rule out the possibility of a sudden drop in temperature for the cause of the deaths of millions of fish.

Important seafood in Southeast Asia, the milk fish aquaculture is one of the major revenue sources of Philippines economy. Such a huge mass kill of fish has not occurred before in Manila, an official said, adding that it's a great loss to the country.

View pictures below.

Also view:

Millions of dead fish choke California harbor (PHOTOS)

California Climate change California Climate change