VIVA – Allegations while the death of millions of fish in the floating net cages of the waters of Lake Toba, North Sumatra, is caused by a lack of oxygen. Because the capacity of the floating net cages is not comparable in the number of fish.
"Another cause is the high density of fish populations in floating net cages, which greatly disrupts the circulation of oxygen, resulting in a lack of oxygen supply and causing the death of fish," Samosir Regent Rapidin Simbolon told reporters on Friday, August 24, 2018.
Another suspicion is that the water conditions in the largest lake in Asia are retreating and the weather conditions are strong. This affects the difference in water temperature on the surface and the mass movement of water from the soil to the surface.
The location of floating net cages is too shallow because the water drains from the lake so that the bottom of the water is muddy.
The action that Samosir Regency Government undertakes is to evacuate dead fish from floating net cages and bury them on land using heavy equipment (excavators).
"At the moment, the agricultural service has had samples of fish, water and feed examined in the Medan laboratory to scientifically determine the deaths of these fish," said Rapidin.
He appealed to farmers to drive cages to empty cages for at least two months and wash the nets and all equipment so that the situation would be normal and not contaminated with dead fish.
"As a result of the incident, eighteen families with a total number of dead fish were estimated at 180 tons of goldfish and tilapia and the loss of millions of fish was estimated at billions of Rupiah," he said.