European eels have a fascinating life cycle, spawned as larvae in the Sargasso Sea near Bermuda before travelling with the Gulf Stream to Europe, developing into glass eels. Upon reaching coastal areas they migrate up rivers and streams, such as the River Brent, which forms a large section of the Grand Union Canal, turning into elver (baby eels) as they hit freshwater.
However, their migration into the upstream waters and ponds where they mature has many obstacles. Weirs, which help to prevent flooding, make it difficult for the elvers to complete their journey and so we're supporting Thames River Trust to install passes, which will allow them to pass unhindered.
Stopping hungry herons
The first of four elver passes is now being installed at Boston Manor on the Grand Union Canal. This sandwich pass has long bristles and a very gentle water flow, which allows the elver to crawl along the walls of the weir and into the next stretch of river. The elvers mimic wet grass being pressed against the wall, stopping hungry herons snatching them from the water.
Working with our partners, we'll monitor the success of these passes over the next year which will allow the partnership to update the design of future elver passes.
Leela O'Dea, environment manager at the Canal & River Trust says: "I am really excited to be involved in the design and installation of elver passes, these are amazing animals with an unequalled journey, it is a testament to the natural environment and those working in it that such strong partnerships can be developed to bring about important changes within the river systems."