In order to better understand how brown trout use the Clutha River system, a trapping programme has been undertaken on the Lindis River by Otago Fish and Game and Clutha Fisheries Trust.
The Lindis is a major tributary of the Clutha River system and the aim of the programme was to better understand how fish used the whole system, Fish and Game officer Cliff Halford said.
"We wanted to know where the fish are coming from and where they are going."
The trapping was in June and July, when fish return to spawn.
A special trap was constructed and 54 fish were measured, weighed and tagged. It was hoped anglers would recapture the fish and provide information such as where and when the fish were caught, Mr Halford said.
In a report presented to the Otago Fish and Game Council this week, he wrote that two fish had so far been recaptured.
He also wrote "it is estimated that up to 30% of Lake Dunstan brown trout use the Lindis River as spawning grounds. [Previous] surveys revealed that fish spend one-two months in the river over the winter and use the mainstream and side tributaries along the first 50km of the river to spawn".
However, because of "heavy over-allocation of water to out-of-stream uses", younger fish in the Lindis River experienced a high mortality rate.
