Atlantic salmon at risk as migration barriers prompt new Environment Agency study.
The Environment Agency has launched a study to identify ways to improve the migration of Atlantic salmon from the River Itchen in Hampshire to the sea, amid warnings that the species is at risk of local extinction.
The agency said juvenile salmon, known as smolts, are struggling to pass structural barriers in the lower river, particularly between Woodmill and Mansbridge in Southampton, contributing to a sharp decline in population numbers.
Dr Dave Rumble, chief executive of Wessex Rivers Trust, which is supporting the study, said: “Extinction is looking like a real possibility within a small number of years if we don’t really rally some activity.” He described the outlook for salmon as “pretty bleak” unless action is taken, according to the BBC.
The River Itchen, a designated Special Area of Conservation, has seen significant changes over the past decade. According to the Environment Agency, infrastructure originally designed for trade and water control now impedes the free passage of fish.
The agency said: “These structures present the biggest obstacles for smolts, especially in large groups. The delay impedes their migration and worsens the odds of them completing their lifecycle and eventually returning as adults to spawn.”
Project manager Jackie Mellan said the study, which will run until October, aims to identify suitable options to restore salmon migration routes. These may include habitat improvements, modifications to existing barriers, and increased community engagement.
The UK’s Atlantic salmon population has been in long-term decline due to a combination of factors including climate change, habitat loss, pollution, and migration barriers. The Environment Agency’s latest intervention comes amid growing concern that populations in southern English rivers are becoming increasingly fragile.