Young salmon have been spotted in a section of the River Elan in Powys for the first time in decades.
Salmon and brown trout under the age of one were found in the water just downstream of Elan Village.
It follows a three-year scheme to restore the ecology of 4.3 miles (7km) of the tributary downstream of the Elan Valley dams.
The Wye and Usk Foundation, Welsh Water and Natural Resources Wales have been behind the work.
"Finding juvenile salmon there is a sign that we are heading in the right direction.
"However, the job is only part done. We need to continue adding further amounts of gravel to complete what is already a very successful project and to continue to monitor the results."
Completed in 1905, the dams cut off the natural source of riverbed gravels to the lower Elan while the river's existing gravels have steadily been washed away.
This left the river lacking the sediments needed for aquatic life to thrive but over the last two years, 2,300 tonnes of new gravel has been introduced to the Elan.
Initial surveys in 2017 showed a recovery of invertebrates in the newly gravelled areas and they were followed by sightings of adult salmon spawning in these areas last winter.
Now the young fish have been recorded there for the first time since monitoring began in the early 1970s.
There has also been a large increase in salmon numbers further downstream.