Wild fish in North Canterbury lake tagged for first time in bid to track migration

Monday, 15 June 2026

Wild fish are being tagged for the first time in North Canterbury’s Lake Coleridge in a bid to track the migration of fish into spawning grounds.

Fish & Game staff have been tagging trout in Lake Coleridge since mid-May to gather data and migration patterns of the wild fishery.

North Canterbury Fish & Game field officer Jackson Meecham said the main aim of the project was to find out if trout were getting through to the Harper River’s upper spawning grounds.

The Harper River was diverted into Lake Coleridge using an artificial channel which was built in 1921 to boost lake levels for renewable hydroelectricity generation at the downstream Coleridge Power Station.

North Canterbury Fish & Game ranger Harry Graham-Samson nets another rainbow trout before tagging it on Lake Coleridge.

Meecham said it would provide valuable information for the future sustainability of the fishery.

“We have always assumed trout are coming from the lake but we want to know for sure if they are travelling through that diversion,” he said.

The team had tagged about 40 wild rainbow and brown trout in the lake near the diversion so far. The goal was to tag up to 70 fish this year before the start of the spawning season.

A North Canterbury Fish & Game ranger releases another rainbow trout after tagging it on Lake Coleridge.

He said the programme would take two to three years and different coloured tags would be used each year.

“It will take some time before we see if the fish are up there. It’s important for the sustainability of the population long term that we know they are getting to those waters and that’s going to help us with confidence to set bag restrictions or limits for the lake,” he said.

It was the first time since Fish & Game’s inception wild trout were being tagged, he said.

The project would tie in with the team’s annual survey of the fishery’s spawning ground. He asked the public to contact the North Canterbury Fish & Game regional office if they caught a tagged fish.

Graham-Samson tags trout on Lake Coleridge in the Canterbury high country on a fine early winter’s morning.

They wanted to know its location and size when caught and if it was kept or released.

“Catching a tagged trout is viewed by anglers as a trophy catch so it’s quite exciting to provide that opportunity in one of the region’s most popular lakes.”