Typhoon causes fish kill in Lake Buhi

BUHI, Camarines Sur—Typhoon “Lando” did not just wreak havoc in northern Luzon but also in its periphery in this province.

Lando (international name: Koppu) caused an upswelling at the bottom of Lake Buhi in this town, resulting in a massive fish kill of cultured tilapia valued at an estimated P14.5 million, said Dennis Del Socorro, director of the Bureau of Fisheries and Aquatic Resources (BFAR) in Bicol.

Buhi is the biggest lake in Bicol located in Buhi town in Camarines Sur where the smallest commercial fish, locally called “sinarapan” (Mistichthys luzonensis), is found.

Some 114 metric tons of tilapia owned by 68 fish cage owners were lost in Monday’s fish kill, a consequence of the bad weather condition since Friday last week.

The typhoon dumped heavy rains into Lake Buhi, stirring decaying matters at the bottom that caused the generation of ammonia and the depletion of oxygen in the water, Del Socorro explained.

Fish kill also happens during long dry season when a sudden downpour occurs for consecutive days, followed by an abrupt change of weather to bright searing sun, which disturbs the lake environment.

The biggest fish kill in Lake Buhi happened in October 2010, when 90 percent of 19,000 fish cages that were randomly put up across about 70 percent of the 1,650-hectare lake area were affected, according to Ronilo Real, lake development officer. Losses were estimated to reach P80 million.

Real attributed the phenomenon to overstocking and increased lake pollution, which had prompted the local government to dismantle more than 3,000 fish cages to clear areas for navigation and a communal fish sanctuary.

A study conducted by the BFAR’s Fish Health Section in 2010 found that five fish kill incidents had been caused by overstocking and had brought losses to as high as P33 million in 1998.

It said “the lake’s dissolved oxygen was very low, the ammonia nitrogen level was very high in 11 stations monitored in the lake, and high toxic traces of hydrogen sulfide were also detected.”