Since 2010, the Waitaki Riparian Enhancement Society (WRES) has been operating a little-known salmon hatchery at Bell’s Pond, on the north bank of the Waitaki River.
Anglers are now reporting catching tagged fish, suggesting the hatchery is adding dozens of fish to the Waitaki salmon stock.
It was pleasing that more than a decade of hard work was paying off, WRES treasurer Linn Koevoet said.
"We are seeing an increase. Something is working," Mr Koevoet said.
In 2009, concerned Waitaki anglers formed the WRES in response to declining salmon numbers.
The group set up a salmon hatchery at the abandoned ICI Watties salmon facility, at Bell’s Pond.
The hatchery was built in 1969, when commercial salmon farming was just beginning in New Zealand.
Initial attempts to release smolt (young salmon) failed and the hatchery was abandoned.
The society has had better success.
This year, 13 salmon, fin-clipped by the society before they were released, were reported by fishermen, giving the WRES its "best return yet".
"Fish and Game has a formula that, roughly, one-third of the returning salmon get caught by anglers," Mr Koevoet said.
It was pleasing to know they were making a difference.
The hatchery now has about 200 3-year-old salmon that can be used for breeding.
At the incubation site, on the Dairy Holdings Ltd farm on the south side of the river, there were a further 74 females and 61 males ready for egg harvest.
Another indicator of larger salmon numbers came from Fish & Game surveys.
Mr Kovoet said last season’s survey found there were 176 "reds" (sockeye salmon).
Four seasons ago, there were none.
In addition to the hatchery, other factors have helped grow the number of salmon in the river, particularly the sea-run salmon bag limit, Mr Koevoet said.
Introduced in 2021, the bag limit restricted each licensed fisher to only two sea-run salmon per season.
Previously, some anglers were catching 10 to 20 salmon in a season.
Efforts to increase salmon numbers still faced several challenges, Mr Koevoet, who is also the South Island Fish & Game Council chairman, said.
Challenges included climate change, water extraction, nitrogen and phosphorus levels in the water, events at sea, nature’s food supply and didymo.
"Didymo has been one of these insidious problems that people don’t really talk about because it’s done an awful lot of damage to the ecology of the river," Mr Koevoet said.
"Worldwide we don’t have a solution on how to combat it."
The society relies on volunteers and donations. Its biggest expense is the 3.5 tonnes of fish food it uses each year.
The group also runs school and group tours of the hatchery and incubation facilities.
The next salmon release will be next May and June.
— Jules Chin, Cadet reporter
