Riuwaka Trout Population Boosted

Trout flying bright green streamers were released into the Riuwaka River Yesterday.

150 brown trout which had been raised from fish caught in a neighbouring waterway were tagged, trucked and released in a day long operation by Nelson/Marlborough by Fish & Game staff.

Above Right: Fish & Game Officer Jacob Lucas releases one of the tagged trout into the Riuwaka River.

Nelson Marlborough Fish & Game Manager Rhys Barrier says having a local source of trout and salmon grown on contract for Nelson Marlborough Fish & Game region will hopefully be of real benefit to licenced anglers.

“We carried out the release of adult brown trout into the Riuwaka River (formerly Riwaka) in order to try and boost the flagging population in this river, which was once a superb fishery.

Fish & Game staff will use this research project to investigate recruitment issues in the fishery.

With the trout only able to spawn in the main steams of the Riuwaka River, and the river being subjected to flooding events recently, and other human activities such as unsympathetic earthworks and sedimentation issues, the trout population has suffered.

The fish that were released were part of 1000 fish had been electrically fished from a neighbouring river so are effectively the same genetic stock.

The trout were taken over to the Wairau Valley were they were raised in ideal conditions by Pieter Wilhelmus in his hatchery to improve their chances of survival.

Yesterday 150 trout that averaged about 1.1 kilograms in weight were selected and tagged then trucked the 160 kilometres back to the Riuwaka and released into three sites along the river.

Fish & Game ask that anglers who catch the tagged trout release them if possible in the first year, but still let them know the tag number, date, time and location that the fish was caught.

This will enable Fish & Game staff to track the movement of the fish, the project will run for the coming three years.

Barrier says “Licence holders are reminded to get out there and make the most of the current fishing opportunities, noting that Riuwaka will close to fishing on April 30th”.

Fish & Game Field Officer Jacob Lucas says that after a wet summer, fishing conditions in Nelson and Marlborough’s Rivers are now excellent.

“Many rivers are hitting form, including local mainstays such as the Motueka and Wairau Rivers which are currently fishing very well, with the rivers in great shape, and good numbers of fish present,”.

“While trout can be fussy at times, you’ll find success at this time of year if you target willow lined edges, and riffle habitat, using small nymphs and dry flies or cicada imitations.

Lucas says “Trout are making the most of the terrestrial bonanza at the moment with passion vine hoppers and cicadas largely on the menu. Spin anglers are best to target the top water areas in the evenings, when trout sit just underneath the surface intercepting mayflies,”.