The Environment Agency are introducing thousands of new fish into the Clow Beck, River Wear and River Tyne, as part of plans to develop and restore rivers in the region.
These rivers have suffered from poor water quality and habitat degradation.
The Environment Agency is also restoring fish passage upon the River Gaunless by removing a redundant weir near Bishop Auckland that blocks the passage of species like dace, and the Wear Rivers Trust have carried out habitat improvement works to provide good fish cover and spawning.
The introduction of dace will help kick-start the recovery of the River Gaunless.
Fisheries officers target fish stocking activity using data from national fish surveys to identify where there are problems with poor breeding and survival.
"We are pleased that we can provide these fish for stocking as part of our obligation to rod licence-paying anglers. Restoration and the creation of new fisheries for everyone to enjoy is a very important aspect to our work."