The Lewiston Tribune –
Fisheries managers and researchers are gaining confidence that sturgeon in the Hells Canyon reach of the Snake River are reproducing.
Studies aimed at capturing young sturgeon, sturgeon larva and eggs in 2014-16 gave fisheries officials some alarm when they failed to document any young fish in Lower Granite Reservoir — a known sturgeon rearing area. A previous population survey conducted from 2012-14 indicated the sturgeon population was stable but also documented a possible decline in young fish.
The once-a-decade population survey prompted officials to look for evidence of successful sturgeon reproduction and survival, known as recruitment. They focused those efforts in Lower Granite Pool — the slack water portion of the river starting near Lewiston and extending downstream to Lower Granite Dam.
“It’s believed that a good portion of the sturgeon eggs that hatch — the larva will drift down into Lower Granite Pool,” said Joe DuPont, regional fisheries manager for the Idaho Department of Fish and Game at Lewiston. “They have a drift period of about two weeks, where they are slowly or (quickly) moving down river, dependent on current.”
The effort to locate young fish and successful reproduction in the pool began in 2014. For three years, Idaho Power Company sturgeon biologists were unable to document sturgeon recruitment there.