Thousands of young salmon will be released into the River Stour near Kidderminster today in a bid to re-introduce them to Midland rivers.
The fry will be released by the Environment Agency following a massive investment to improve water quality on the Stour in the past few years.
The species was previously present in the river but industrialisation and urbanisation resulted in a decline in water quality, robbing the fish of their habitat and the species they fed on, causing them to die out.
Improvements to discharges over the past few years and a decline in industry has resulted in oxygen levels increasing and pollution dropping.
These improvements have resulted in salmon being found in the lower reaches of the river where it meets the Severn.
Today's stocking is being carried out to boost these small numbers in the lower reaches by stocking salmon fry into the upper reaches to encourage their further migration downstream into the Severn and eventually into the sea.
The young salmon have been reared by hatching eggs from wild-caught salmon, a scheme which is run by the Environment Agency in partnership with Severn Trent Water.
Up to 350,000 salmon eggs are obtained from local stock each year. They are fertilised and hatched in purpose-built tanks and used to restock throughout England and Wales. Some of the fry are micro-tagged before being released so that marine survival in the returning adults can be assessed.
However, water quality improvements alone are insufficient to restore salmon to their former breeding gravels in the upstream stretches of the river. Obstructions have been built in the river in the past.
The fish cannot negotiate these obstacles, limiting upstream migration. The Environment Agency has started a programme to investigate the removal of these obstructions and intend to work with their owners to seek opportunities for removing them.