More than 8,000 fish were found dead in a dam in Ranchi, following which the fisheries department ordered a probe into the incident, an official said on Sunday.
Fish, weighing 500 gm to 1 kg, were found dead in four cages laid for fish rearing in Getalsud dam, district fishery officer Arup Kumar Chaudhary told PTI.
State Agriculture Minister Badal Patralekh ordered a probe into the incident on Saturday evening.
Badal directed the department secretary to carry out a probe into the matter on Sunday and submit a report at the earliest.
Chaudhary said he and his team would visit the dam during the day and try to find out how the fish died.
"There might be several reasons for the death of fish such as lack of oxygen, diseases or pollution. We suspect a lack of oxygen or disease could be the reason for the death of these fish. However, the exact cause could be ascertained only after we finish our probe," Chaudhary said.
He said that ideally, the oxygen level in water should be five milligrams per litre or more for the survival of fish.
If it declines below three milligrams per litre, fish die, he said.
Chaudhary said there are around 300 fish cages in the Maheshpur area, adjacent to the incident site and about one and half tonne of fish are being reared there but all of them are safe.