Plans have been lodged to install rock ramps in a Cumbrian beck in a bid to help the migration of a critically endangered species.
South Cumbria Rivers Trust has submitted two planning applications to Westmorland and Furness Council to install rock ramps at the upstream and downstream weir on Pennington Beck, near Ulverston, to help the migration of eels.
The weir acts as a barrier to migration as they are not passable for small fish or eels, the trust said.
There has been a drop in eel numbers of over 90 per cent in UK rivers in the last 25 years with the reasons not yet fully understood, it added.
A barrier to eels moving upstream to feed in British rivers is the presence of human-made structures and modifications, such as weirs, plans state.
Plans said the main project aim is to ease migration for the European eel and added the rock ramps would primarily benefit eel elvers which are smaller and found the weirs difficult to navigate.
A rock ramp would see a set of rocks or boulders installed in a gentle slope from the bottom to the top of the barrier, creating a series of pools for eels and fish to rest and the move up the barrier.
The European eel starts its life 4000 miles away in the Sargasso Sea. Soon after hatching as transparent glass eels, they start the journey towards Europe using the Gulf Stream.
Once in Europe, the eels enter the freshwater system, growing into elvers in becks and rivers where they can remain from five to 20 years. The last stage of their life is as silver eels, where they return to the Sargasso Sea to breed and then die.
They are on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.
The two planning applications are undergoing public consultation.
