A fish pond worker scoops up dead milkfish locally known as Bangus after thousands of them were found floating on Taal Lake in Batangas province, south of Manila, Philippines, Sunday May 29, 2011.
 
The Government Bureau of Fisheries and Aquatic Resources are still investigating the cause of the fish kill. The damage of the fish, the most in-demand fishes in the country, is estimated at least 50 tons.
 
More than 800 tons of fish have died and rotted on fish farms in a lake near Taal volcano south of Manila, with authorities blaming it on a sudden temperature drop.

The massive fish deaths started late last week but have eased. Officials have banned the sale of the rotting fish, which are being buried by the truckload in Talisay and four other towns in Batangas province, Bureau of Fisheries and Aquatic Resources official Rose del Mundo said Sunday.

The deaths are unrelated to recent signs of restiveness in Taal volcano, which is surrounded by the lake where many villagers have grown milkfish and tilapia - staple food for many Filipinos, officials said. The volcano and lake are a popular tourist draw.

Talisay agricultural officer Zenaida Mendoza said an initial investigation showed the deaths may have been caused by the temperature change as the rainy season set in last week after a scorching summer, which also depleted the lake's oxygen levels.