The head of an environmental charity has expressed concern that Atlantic salmon could face extinction if their young are unable to reach the sea.
The Environment Agency has launched a study to explore ways of supporting the species’ migration from the River Itchen in Hampshire to the ocean.
According to the agency, juvenile salmon in Southampton – known as smolts – are struggling to navigate barriers along the river, contributing to a decline in their population.
Dr Dave Rumble, Chief Executive of the Wessex Rivers Trust, said the outlook for the salmon was “pretty bleak” unless significant changes are made.
He added: “Extinction is looking like a real possibility within a small number of years if we don’t really rally some activity.”
The Environment Agency will be focusing its investigation on the lower stretch of the River Itchen, between Woodmill and Mansbridge.
By October, it aims to “identify suitable options” to support salmon populations, which may include river habitat enhancements, improved fish passage, and increased community engagement.
Jackie Mellan, the agency’s project manager for the study, said: “The River Itchen has really changed in the past 10 years.
“The first step is finding out what can be done to improve the river system and increase its ecological resilience. For salmon that means improving migration to the sea and boosting their odds of returning to spawn.”
Each spring, shoals of juvenile salmon begin their journey from the Itchen to the sea. However, experts warn that many are “struggling to get past the first hurdle” due to environmental changes in and around the estuary.
In a statement, the agency explained: “It was once used for transport and trade as a sea lock and onward travel to Winchester. Now, the current structures control water levels through Riverside Park.
“These structures present the biggest obstacles for smolts, especially in large groups.”
It said the change in water velocity makes smolts “bunch up”, adding: “Eventually the current carries them over or under the structures and back onto their journey to the sea.
“But the delay impedes their migration and worsens the odds of them completing their lifecycle and eventually returning as adults to spawn.”
The agency is now working with partners, including the Wessex Rivers Trust, to develop ways to make fish passage “more smolt-friendly”.
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At Natural World Fund, we are passionate about restoring habitats in the UK to halt the decline in our wildlife.
