Authorities are trying to determine where all the fish have gone in Wood Lake.
Spring fishing has been extremely slow, with few anglers landing kokanee.
“There’s been no massive kill-off that we know of but the population has taken an abrupt downturn,” said Paul Askey, a provincial fisheries stock assessment biologist.
“We’ve been getting all kinds of calls from people asking what’s wrong because they’re not catching fish this spring.”
Technicians are trying to determine what factors are at play, and one theory is related to poor water quality last year.
“There was a lot of algae and the bottom, cool layer of water ran out of oxygen while the top layer got really warm in the summer,” said Askey.
“It’s the biggest wild stock fishery we have. One of the great things about Wood Lake is the great number of nutrients but it appears to have tipped over the edge last year.”
Kokanee stocks took an abrupt downturn starting last year, and this trend is expected to continue this year based on 2011 acoustic data and 2012 angler reports.
Last year’s spawner return was the lowest on record since regular counts began in 1994.
Askey isn’t giving up on the kokanee fishery.
“We have a number of projects underway,” he said.
Among them is the impact of low water levels in Middle Vernon Creek on spawners.
Besides Ministry of Forests, Lands and Natural Resource Operations, the initiative also involves the Okanagan Nation Alliance, the Oceola Fish and Game Club, the District of Lake Country and the Habitat Conservation Trust Foundation.
“If we fix the water problems in the creek, that may help out,” said Askey.
The ONA is also focused on egg-to-fry survival.
The scope of the situation on Wood Lake should be more obvious this fall when spawning begins.
If both populations (shore and stream spawners) drop off, we know the problem is in the lake,” said Askey.
“If it’s water quality, there’s no easy fix to that.”