Salmon study enters second year as numbers hit record highs

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A PROJECT tracking salmon as they migrate along the Usk River has entered its second year.

Natural Resources Wales (NRW) is continuing its efforts to halt the decline of the species by identifying the challenges it faces on its journey to sea.

The project, supported by the Wye and Usk Foundation, involves catching up to 100 salmon smolts a year and tagging them with acoustic transmitters, which regularly emit high-frequency pings.

A smolt is a stage in the life cycle of salmon where it prepares to migrate to the sea.

The transmitters provide insight into their movements, as well as data on survival rates and migratory behavior, helping to inform future salmon management and conservation work.

An unusually wet May last year led to a good year for migration success in the first year of the project.

At least 67% of the tagged fish managed to travel more than 100 km from the tagging site on the upper reaches of the river to the Severn Estuary.

The fastest individual fish passage time from a monitoring point upstream of Brecon to the last receiver array in the estuary at Newport (95.6 km) was 36.22 hours.

The project is part of the NRW Salmon and Sea Trout Action Plan, which aims to understand and address the many factors contributing to the decline of these fisheries.

Oliver Brown, Aquaculture Manager, leading the project for NRW, said: “The number of salmon, adults and juveniles, is at an all time high in Welsh rivers, as well as in other parts of the world, and we must all do what we can to preserve them and safeguard the survival of this iconic species.

“The project will give us a good indication of what is happening to these fish at a critical time in their life cycle.

“Previously, we didn’t know how many smolts went out to sea, so this project gives us a good indication of survival rates, as well as helping us understand how perceived barriers can affect migration, for example, bridge footings or the weirs.

“Learning from the results of the first year, we have deployed 15 additional receivers along the Usk River this year, bringing the total to 46, to help increase the accuracy of detection data. We have also made changes to our trapping methodology to increase efficiency.

“We are grateful for the continued support of the Wye and Usk Foundation on this project. Ultimately, the information and data we gather will inform our collaborative salmon conservation work, which will prove invaluable in our efforts to address the cause of long-term population decline.

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