Hundreds of fish have been removed from the river

The Environment Agency will be taking to the river on Tuesday to scoop out the fish, which have died because of low oxygen levels caused by the current warm weather.

It is feared there could be a record number of dead fish in the river.

The agency has already removed 600 dead salmon and 33 sea trout from the river and is expecting to pick up another 50 a day while the warm weather continues.

Most of the fish have been found in the tidal area between Wylam and Newburn.

Drinking water

To try to combat the problem, the agency has twice released better-oxygenated water from Kielder Reservoir into the river in an effort to help salmon move out of the estuary and into the freshwater section of the river.

Roger Inverarity, water quality technical specialist, said: "We arranged for a similar release from Kielder for two days starting on July 25.

"This coincided with a small amount of rainfall and apparently encouraged some fish to move upstream.

"Over a three day period, the number of fish counted through the agency's fish counter at Riding Mill near Corbridge was about 400 higher than the preceding three days.

"But the total number counted throughout July was 6,000, so while the release appears to have resulted in extra fish movement it was not a spectacular result.

"With the current hot weather... we arranged a further two day release of water from Kielder last Thursday."

The water released over these two days would be enough to supply all of Tyneside with drinking water for a fortnight.