Thousands of trout, perch and other river fish have been killed in two pollution incidents triggered by blockages in sewers which overflowed into water catchments.
Anglers found stretches of the Pocklington canal, a well-known fishing water near York, filled with dead or dying fish after a debris filter was jammed with sanitary waste.
Hundreds of fish also died after vandals dropped large pieces of timber down a manhole and blocked a sewer close to the river Holme, between Brockholes and Honley in West Yorkshire. Raw sewage backed up and finally spilled into the stretch, which is noted for perch, roach and bream.
Environment agency officials were later called to a third incident in Yorkshire, which saw fish poisoned in the river Worth, which runs past the Brontë village of Haworth to Keighley. A brief illegal discharge of detergent is thought to have polluted a stretch near Keighley for long enough to kill the fish.
A spokesman for the environment agency said that the Pocklington canal could take years to recover, because so many fish had died, along with other parts of the river food chain. The sewage also affected the Pocklington beck, a small stream which feeds into the canal.
Sewage is lethal to fish because it uses up oxygen, leading to other river life suffocating. Yorkshire Water, which manages the sewage system in all three areas, said the blockages were cleared within three hours of them being alerted.
The environment agency appealed for information on the river Worth incident which is thought to have been deliberate.
Anglers found stretches of the Pocklington canal, a well-known fishing water near York, filled with dead or dying fish after a debris filter was jammed with sanitary waste.
Hundreds of fish also died after vandals dropped large pieces of timber down a manhole and blocked a sewer close to the river Holme, between Brockholes and Honley in West Yorkshire. Raw sewage backed up and finally spilled into the stretch, which is noted for perch, roach and bream.
Environment agency officials were later called to a third incident in Yorkshire, which saw fish poisoned in the river Worth, which runs past the Brontë village of Haworth to Keighley. A brief illegal discharge of detergent is thought to have polluted a stretch near Keighley for long enough to kill the fish.
A spokesman for the environment agency said that the Pocklington canal could take years to recover, because so many fish had died, along with other parts of the river food chain. The sewage also affected the Pocklington beck, a small stream which feeds into the canal.
Sewage is lethal to fish because it uses up oxygen, leading to other river life suffocating. Yorkshire Water, which manages the sewage system in all three areas, said the blockages were cleared within three hours of them being alerted.
The environment agency appealed for information on the river Worth incident which is thought to have been deliberate.