STUNNED onlookers enjoyed seeing two large fish swim past the Diglis Fish Pass viewing window.

Two large Chub were among some of the wildlife which made its way across the window during the Unlocking the Severn drop-in event.

A group of excited onlookers on a tour watched on as the fish made their way past, with a smaller Dace also making an appearance.

This was filmed during the early tours at the event, which commemorates the return of the endangered Twaite Shad to the River Severn as they migrate into freshwater.

READ MORE: Excited groups visit Diglis Fish Pass to mark return of endangered fish 

What is a fish pass?

The purpose of a fish pass is to allow fish to move past manmade blockages in water. In Diglis, the weir means that many fish looking to travel upstream struggle due to the two-metre separation.

The weir was installed in the 1840s to create a deeper, more reliable pool of water upstream for boats.

Stronger fish like salmon are occasionally able to get past the weir by jumping, but many species do not possess the required strength.

The pass consists of 11 small pools, each just 20 cm higher than the last, making it more manageable for the fish to swim through.

The fish detect the stream of water in the river and can travel upwards, with walls in each pool relieving some of the force created by the water. 

For more information about the Diglis Fish Pass and to book trips, visit https://www.unlockingthesevern.co.uk/diglis-island-fish-pass-tours/.