For the fourth year in a row Hill Creek Spawning Channel, north of Nakusp, has exceeded a 50 per cent egg-to-fry survival. Recent fry counts show that 67 per cent of the eggs laid in the channel’s gravel in the fall of 2009 survived. The fry then migrated toward Arrow Lakes Reservoir in early summer 2010. This is also the second highest egg-to-fry survival since 1989.
The kokanee spawning channel is jointly run by the Ministry of Environment (MOE) and the Fish & Wildlife Compensation Program. The FWCP works on behalf of its program partners BC Hydro, MOE and Fisheries and Oceans Canada to conserve and enhance fish and wildlife impacted by the construction of BC Hydro dams.
“This long run of high survival rates shows that our local contractors are doing a good job in the maintenance and operation of the channel, and that those involved are paying attention to detail,” said FWCP fisheries biologist Steve Arndt from BC Hydro. “Everything from managing water flows to the annual cleaning of the spawning gravel plays a role in these consistent results.”
Those local contractors include Brian Barney who oversees the day-to-day operations. “Mother Nature certainly was on our side this season; we had few storms and a mild winter,” said Barney. “What made the survival rate so gratifying, however, was the sheer number of eggs deposited in the gravel last fall.”
An estimated 30 million kokanee eggs – the highest ever – were deposited in the channel in the fall. Therefore with an egg-to-fry survival rate of 67 per cent, more than 20 million kokanee fry headed out from the channel this year, which is well above the usual kokanee loading rates for the reservoir.
The high egg deposition coupled with the high egg-to-fry survival ratio have biologists rethinking the capacity of the spawning channel that was built in 1980 with BC Hydro funds as partial compensation for spawning habitat lost due to the construction of Revelstoke Dam.
“In short, the fry production in 2010 is well beyond the original design criteria and clearly the channel is capable of producing a lot more fry than was thought possible when it was built,” said Arndt. “This means we have an opportunity to better understand how record spawning channel fry numbers will affect food web efficiency, kokanee spawning in other tributaries, and recreational fisheries in the Arrow Lakes Reservoir for the foreseeable future.”
For more information contact: