Thousands of fish were ‘stunned’ by an electric current to safely move them while repairs were carried out to part of the Wey and Arun Canal.
The two-day operation saw 7,000 fish moved from a half-mile stretch of the canal to another while a section near Billingshurst was drained.
The Wey & Arun Canal Trust called on specialist environmental company Aquamaintain to help with the move.
The firm used a process called electrofishing to catch the fish in a part of the canal at Drungewick.
A trust spokesman said: “This humane and Environment Agency-approved method involves passing an electric current through the water from a generator onboard a small boat.
“The field of electricity causes the fish to swim towards the positive charge and become momentarily stunned, allowing the fish catchers in the water to net them and transfer them within seconds into fresh water containers onboard the boat.
“From there they are moved to a tank of oxygenated water on the towpath, where they can then be discharged into another part of the canal.
“The process results in no lasting harm to the fish, which return to their natural state within minutes.”
Aquamaintain fisheries consultant Dave Hellard said the process was the most humane way possible to move the fish. “The fish recover quickly, and once in the oxygenated water tanks quickly become pretty lively again,” he said.
“The team in the water carefully monitor the voltage and and go back and forward over the area to be sure that as many of the fish as possible are caught.”
The process allows the experts to assess the health of the fish living in the canal, as well as look at the size of fish and species that thrive there.
The team gave the Wey & Arun Canal fish a clean bill of health with pike, eels, bream, roach and carp among the fish caught.
The trust had to drain the Drungewick stretch of canal to allow leaks to be repaired.