Rare fish set for Welshpool Severn return

One of Britain’s rarest fish could be returning to its Welshpool breeding ground next year for the first time in almost two centuries.

The little-known twaite shad, a member of the herring family, was once common in British waters with thousands of the fish migrating upstream in spring.

Numbers dwindled after weirs constructed in the 19th Century posed barriers to migratory fish.

But the BBC is reporting that a conservation project is trying to unlock the river for fish by creating routes around several weirs.

The Unlocking The Severn project by the Canal & River Trust, Severn Rivers Trust, Environment Agency and Natural England is in the process of reopening 150 miles (241km) of the river for twaite shad by creating routes around four major weirs.

Two large fish passes alongside Victorian weirs near Worcester have been completed as part of the conservation project, the largest of its kind in Europe.

Some fish have already been recorded further up stream and it is hoped that with more work, they could reach Montgomeryshire next year where historical records show they last spawned in the 19th century.

"We have historical records of twaite shad reaching as far as Welshpool," said Jennie Hermolle, communications and marketing officer at Unlocking the Severn. So far we have three of our four fish passes open to the river.

“Unfortunately the third site is still under construction until the autumn – it is the most challenging location as the only access for plant and material is via river barge so this site has been most severely impacted by higher river levels, and having the longest build-time as a result.

"So for the twaite shad to have the chance to get all the way to Powys it will be the 2022 shad run.

"However we’re already seeing salmon using the passes, so it should help more Salmon reach higher upriver, more easily. So those benefits will be immediate.”

The shad prefer to spawn in flowing water over gravel beds at night, in noisy “bull” events with lots of splashing as the male and female swim in a tight circle, as if chasing each other, as the eggs and milt, or semen, are released.

Although the events take place under cover of darkness, the distinctive sound can be recorded from the river bank to estimate the number of spawnings in different locations.

Good spawning conditions can result in a peak year for new shad, which can live for eight to 10 years and return to the river up to five times to spawn, so monitoring near Worcester as part of the project could give an early indication of the prospect for the population in coming years.