Record low juvenile salmon counts on River Frome raise extinction concerns.
An annual monitoring programme on the River Frome in Dorset has recorded the lowest number of juvenile wild Atlantic salmon since surveys began more than two decades ago, reinforcing warnings over the species’ long-term viability in UK rivers.
Conservationists from the Game and Wildlife Conservation Trust (GWCT) counted and tagged 3,226 juvenile salmon during their four-week summer survey, less than a third of the 10,000 fish they typically aim to sample and below last year’s previous record low of 4,593.
Will Beaumont, senior research assistant at GWCT, told The Times: “Last year was the worst we’ve ever had, but this year has been catastrophic. This follows on from yet another year where we have seen a new record low number of adults returning from sea to spawn, confirming the continued steep decline of salmon in our rivers.”
Numbers of wild Atlantic salmon in the UK are estimated to have fallen by about 80 per cent over the past 40 years. Rivers that held tens of thousands of fish in the 1980s now support only a few hundred, and wild Atlantic salmon are classified as endangered in the UK and placed on the International Union for Conservation of Nature Red List alongside species such as elephants, pandas and polar bears.
The River Frome is one of GWCT’s key index rivers. Each late summer, a research team based at the charity’s river laboratory near Wareham spends four weeks catching, weighing, measuring and microchipping juvenile salmon, or parr, that hatched in the spring. Teams move to a different section of the roughly 20-mile river each day in order to sample as much juvenile habitat as possible. The work has been carried out for around 20 years.
Dylan Roberts, head of fisheries at GWCT, described the latest figures as “alarming” and warned that “if it continues, salmon could disappear from our UK rivers in the next 30 years”. He added: “It is also sadly reflective of what’s happening in other rivers in the UK and more widely in Europe. Almost all salmon rivers in England and Wales are classified as at risk by the government bodies.”
Roberts said the pressures on salmon are “many and complex”, citing tougher marine conditions linked to global warming and concerns over bycatch, but argued that action on freshwater habitats remains critical. “If we are able to improve conditions in our rivers, and make sure they can grow fitter, larger and stronger and reproduce in greater numbers, they will stand a better chance, once they migrate to sea, of returning in larger numbers,” he said.
On the Frome, GWCT staff have recorded a “huge increase in the growth of algae between spring and autumn”, Roberts said. Excessive algal growth reduces oxygen levels and smothers habitats used by juvenile salmon and the insects they feed on. According to GWCT, the algae is fuelled by high levels of nutrients, particularly nitrate and phosphate, entering rivers from sewage and septic tank discharges and from fertilisers and manures washing off agricultural land.
Eroding river banks killing salmon?
Researchers have also reported more fine sediment, or mud, entering the river from eroding banks and ploughed fields, where it settles on gravel beds and can suffocate salmon eggs.
“To create a better future for salmon, we need to tackle these issues together and at scale,” Roberts said. “To date, projects have been too small and patchy, mainly due to a lack of funding and bureaucratic challenges around farming and conservation, to make the changes needed.”
GWCT’s response has focused on landscape-scale collaboration with farmers and other land managers. The trust developed its Farmer Cluster model in 2012 to bring together neighbouring landholders to work on shared environmental targets. In 2022 it helped launch the Environmental Farmers Group (EFG), a farmer-led cooperative designed as an umbrella for clusters and individual farms seeking funding for habitat restoration and emissions-reduction projects. The EFG now represents 541 farmers across 341,404 hectares in regions including the South East, South West, the Midlands and Yorkshire.
Colin Smart, from the Environmental Farmers Group Dorset, said work was under way on a catchment conservation plan for the Frome in partnership with GWCT’s fisheries team.
“With a sufficient blend of investment from both the private and public sector, the catchment plan has the potential to reverse the catastrophic decline of salmon in the Frome, which is an indication of the poor health of the entire river system,” he said. “Farmers do care about the environment and can make a real difference but also need to produce food and make a living. They need adequate compensation to put the right measures in place.”
