Manila Bulletin, Philippines : 70,000 kilos of fully grown tilapia lost to ‘fish kill’ in Isabela

03/20/2003

70,000 kilos of fully grown tilapia lost to ‘fish kill’ in Isabela

ILAGAN CITY (PNA) — At least 70,000 kilos of fully grown tilapia fish floated dead in the Magat River in this province.

The “fish kill” that has also devastated some 1,000 fishpens and fish cages since March 13 this year has also wreaked havoc on the entire fishing industry in Isabela.

Antonio Ramos, operations manager of the National Irrigation Administration’s Magat River Integrated System (MRIS), said the operators of fishpens and fish cages incurred heavy losses.

The operators estimated the damage at R4.9 million based on the R70-per-kilo price of tilapia.

Ramos said at the rate the water level of the Magat River is receding, it is likely that the “fish kill” would also affect other areas where the river snakes through.

The volume of the affected tilapia accounts for at least 20 percent of the total tilapia population in the province, it was learned.

The freshwater-fish producers in the region registered a yield of 105,362 tons of fish in Year 2000, 83 percent of which are tilapia.

Ramos said the low water level at the Magat Dam and the low oxygen level due to the overpopulated fish cages and fish pens must have caused the “fish kill.”

There are at least 10,000 registered fish cages and fishpens in the Magat River stretch in Isabela and Ifugao.

The fish structures are situated in the towns of Ramon and Cordon, both in Isabela, and Alfonso Lista, Mayoyao and Aguinaldo, all in Ifugao province.

Ramos admitted, however, that there are illegally constructed fishpens and fish cages in some areas in the Magat River.

The Department of Agriculture and the Bureau of Fisheries and Aquatic Resources (BFAR) have already dispatched teams of aquaculturists to investigate the “fish kill” and monitor the situation at the Magat River.

In the meantime, Ramos said, NIA has already requested the Department of Agriculture to conduct cloud-seeding operations to help mitigate the impact of the problem caused by the lack of water.

The operators were instructed to avoid any re-stocking of their fish cages of fishpens because this may cause further pollution.

Ramos expressed fear that the river might develop high level of hydrogen and sulfide, the high toxicity of which could affect aquatic life.

Water pollutants, which contribute to “fish kill,” consist of domestic liquid and solid wastes, organic wastes from pig and poultry farms and tanneries and wastes from manufacturing plants.