Thousands of fish have taken residence at the Falkirk Wheel, the rotating boat lift that links the Union and Forth & Clyde canals.

The freshwater population has increased from just over a thousand in 2003 to 16,000, and includes pike, perch, roach and brown trout. Some were even found in the massive gondolas used to lift the boats the 115ft (35m) between the canals.

Environmental scientist, Olivia Lassiere, says this is great news. ‘Brown trout are more commonly associated with clean Highland lochs and rivers. To have them in the canal is simply fantastic.’

The discovery was made during a wildlife check that takes place before draining the basin. Fisheries consultants temporarily stunned the fish and transferred them to adjacent sections of the canal while the site underwent its annual maintenance.