Often salmon and trout are given greater amounts of attention than our other native fish species, in part due to their popularity amongst anglers and because they are under increasing pressures from a variety of sources. However today we finished the installation of a dedicated ‘eel pass’. Over the course of the last week or two we have installed eel brushes on the Garden Weir on the Lugton Water (tributary of the River Garnock). Low water levels have been necessary to allow us to do this work and we took advantage of low levels to finish this work on what has been a very fine (dare I say spring!?) day.
Essentially eel brushes are stiff bristle brushes, akin to a byre brush mounted in a flexible rubber compound. The bristles act as a climbing substrate for migrating elvers and allow these small fish grip, which the weir lacks as they make their way upstream. The cry from some anglers will always be “I’ve caught eels upstream, so they must get over”. And there is no disputing that eels can get over the weir unaided. However as with any fish species at an obstacle some may get over but many others won’t. Others may just take longer to progress over the obstacle making them more susceptible to predators and increasing the energy expenditure of the migration.
Garden Weir now has a salmon/trout pass to help improve fish passage so why should eels be afforded any less help? With numbers in decline, these highly protected fish need all the help they can get.
We mounted the bristle brushes to a HDPE plastic backboard anchored onto the face of the weir in a recessed channel. The recess will help maintain a flow of water through the brushes in even low levels. See the images below for a rough step by step in the process. We’ll now have to wait until early summer to see if the elvers will use our brushes. I look forward to reporting a good news story in a few months time.
Thanks to our partners in this project, North Ayrshire Council and SEPA.