After deades of decline, salmon have started to return to the rivers Wye and Usk, with last fishing season's salmon catch the highest number for years.
It follows millions of pounds worth of investment by the Wye and Usk Foundation to help improve water quality and to build fish passes.
The numbers of fish in the rivers had started to drop, partly due to commerical fishing and pollutants in the water.
Stephen Marsh-Smith from the Wye and Usk Foundation said the body was concerned that the fish would become extinct from the rivers.
This year things appear to be back on track, and a number of large salmon have already been caught.
Most fish are returned to the rivers to help improve the fish stocks.