Five different types of shark have been discovered in the River Mersey, along with huge eels, sea scorpions and turbot.

In total, 37 different fish species have been confirmed as living in the Mersey, which flows from Stockport through Manchester and Liverpool in England’s north west. The species were recorded by the Mersey Rivers Trust, which ran a citizen science monitoring survey with local anglers throughout 2022.

Smooth-hound, starry smooth-hound and bull huss sharks were all found in stretches between Warrington and the Wirral.

Other surprise discoveries include smelt, a rare small fish, which may even be breeding in the estuary. More than a century ago smelt were very common in the area, with a canning factory in the town of Warrington, but industrialisation and population growth led to them being completely wiped out of the Mersey.

Mersey Rivers Trust’s Mike Duddy said the figure of 37 species was nearly two-and-a-half times the number found in a previous survey in 2002, when no more than 15 species were found.

He said, “Over the last 30 years, there’s been this tremendous regeneration of the River Mersey. This renewal started slowly but is now picking up pace. I still think we’re right at the beginning of something special.”

The River Mersey travels nearly 70 miles, passing through 29 local authority areas, with almost five million people living within its catchment. Its regeneration was kickstarted in 1983, when the then Secretary of State for the Environment Michael Heseltine, said the river was "an affront to the standards a civilised society should demand of its environment”.

The Mersey Basin Campaign launched in two years later in 1985 and began a major clean-up of the entire river. The campaign merged with other groups to form the Mersey Rivers Trust in 2017, which runs ongoing community projects to create a healthier river.

The trust is continuing its survey work with anglers in 2023 and would love to have more volunteers record the species they are catching.