ONE of the largest conservation projects of its kind will see a rare species of fish return to Worcestershire for the first time in 170 years – and you can help.

The endangered twaite shad was cut off from historic breeding grounds in the city’s stretch of the River Severn through the installation of Victorian weirs.

Now, the Unlocking The Severn project by the Canal & River Trust, Severn Rivers Trust, Environment Agency and Natural England is in the process of making available to the fish 150 miles of the river by creating routes around four major weirs.

Two large fish passes alongside Victorian weirs at Diglis and Bevere have been completed as part of the conservation project.

It means that this month the twaite shad – known as the May fish because of the timing of its migration on to the river from the sea to spawn – will be able to swim past the weirs for the first time in nearly two centuries.

The fish passes, which allow the shad to swim upriver of the city, will help species such as salmon, lamprey and eels.

As part of conservation efforts, citizen scientists are also being sought to head out in the dead of night to monitor the distinctive sounds of their spawning.

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 the monitoring could give an early indication of the prospect for the population in coming years.

Jason Leach, programme director at the Canal & River Trust, said: “It’s never too late to give nature the chance to recover.

“And our project’s night-time riverside spawning vigils are a fitting way to begin recording the recovery of the fish affected so badly when our predecessors inadvertently caused a big problem for migratory fish.

“We hope lots of volunteers will be inspired to join us to witness and record the shad spawning phenomenon.”

Other volunteers in the conservation project count shad seen migrating during the day from the riverside to estimate the size of the run. People who want to get involved can find out more online: www.unlockingthesevern.co.uk