A CRACK team of Environmental Agency officers relocated thousands of fish from a shrinking river in North Dorset before they suffocated.

In a race against time the fish, including brown trout, pike, grayling, bullhead and eels, were removed from a series of pools on the River Tarrant, a tributary of the Stour, before they became trapped by low flows.

Using a system known as electro-fishing, the officers introduced a small electric current to the water using a metal probe.

This momentarily stunned the fish and allowed them to be caught and moved to safer waters downstream.

The latest rescue took place between Tarrant Abbey and Manor Farm at Tarrant Keynson, but the team had to move fast because once water stops flowing over the weir at Manor Farm, the one-mile stretch of river downstream of the weir dries out in just hours.

Jim Allan, from the Environment Agency, said: “The Tarrant is a little gem of a stream and is unique to the area.

“It is very productive with its own natural brown trout population.

“Migratory salmon and sea trout still regularly use the Tarrant to spawn, but unfortunately low flows mean the river dries up from the bottom to middle reaches and this makes it difficult for fish to migrate back downstream to the safety of the River Stour.

“Fortunately, local interest in the river is high and people keep us informed when flows become critical. This enables us to respond with actions such as fish rescues.”

Like many chalkstreams, the Tarrant is ground fed.

Flows are reduced and can even stop following prolonged dry weather when groundwater levels drop.

More than 3,000 fish were rescued in a similar operation on the River Tarrant last year.

The Environment Agency has started talks with local landowners and the Tarrant Valley Preservation Society to modify weirs along the river. The idea is to make it easier for fish to migrate down to the Stour and recolonise the upper reaches of the Tarrant with trout and salmon on lower flow years.