Pumping stations are vital pieces of infrastructure that protect large areas of land from flooding and saltwater ingress.
They work by pumping freshwater from the river and into the estuary when the tidal level is too high to allow for the river to drain naturally, whilst simultaneously preventing the intrusion of tidal water into the river. They are particularly numerous in and around the Somerset Levels given the low elevation of the land.
Pumping stations can prevent fish migration in both directions and seaward migrating fish are particularly at risk of injury from various mechanisms including shear stress and strike impact. This includes silver eel, which are mature eels returning to the sea to spawn and are a critical component of critically endangered eel populations.
It was unknown to what extent gold corner pumping station was impacting silver eel (and other fish) escapement and Fishtek undertook a study to determine injury and mortality rates as a direct result of pumping operations. Fish were sampled at one of the pump outlets for multiple 24-hour periods and the fish were sampled from the net with any mortality or injury recorded. Overall mortality rates of 26% and 10% were found for eel and ‘other fish’ respectively and suggestions were made for pump improvements and other mitigation options to reduce eel mortality.