The Environment Agency is investigating the circumstances surrounding a 'vanishing stream' in Buxton.
Around 100 brown trout and bullhead are reported to have died due to the disappearance of water from the unnamed stream, in the Macclesfield Old Road area.
The Environment Agency said its officers have been on the scene performing a ‘fish rescue’, which has saved a further 175 trout and 50 bullheads.
Paul Reeves, who works for the Environment Agency in the East Midlands, said a ‘natural fissure’ is thought to have opened up under the stream.
“Officers have been busy carrying out electro fishing to rescue the remaining fish and transfer them to safety further downstream,” an agency spokesperson told the Advertiser.
“The disappearance of water from the stream is a natural phenomenon which is a characteristic of the geology in this area.
“In the short-term we will investigate measures which can be undertaken as a temporary repair pending evaluation of options for a more permanent solution.
“Our staff work 24/7 to protect people and wildlife and if anyone witnesses any fish in distress they should report the incident to our hotline on 0800 80 70 60.”
Investigations are expected to continue into tomorrow.