Tiger trout primed to pounce at Diamond
Diamond Lake is getting a dose of predatory trout that quite literally will be lying in the weeds while doing their part to keep invasive tui chub and red-sided shiners from robbing the lake of its top-drawer trout fishery.
The Oregon Department of Fish and Wildlife next week will stock the first hybrid tiger trout intended to prey on the unwanted invasives before they take hold in this eastern Douglas County lake.
Tiger trout are infamous for their boldness, willing to stalk their prey in just a few inches of water, the same depths used by schooling chub. By next fall, these tigers will be large enough to turn their attention on eating whatever shiners or chubs they find schooling in the lake's shallows.
"I'm optimistic," says Greg Huchko, the ODFW's Umpqua District fish biologist. "Diamond Lake's pretty shallow overall and plenty of aquatic vegetation to give them cover. I think we're set up, theoretically, but we don't know for sure."
The first 5,000 tigers, about 7 inches long, will be stocked Monday in Diamond Lake. Another 13,000 fingerling tigers will be stocked later this month, ODFW spokeswoman Meghan Dugan says. They will join the 300,000 fingerling rainbow trout also set for release there this month, Dugan says.
Tiger trout are the sterile offspring of a female brown trout and a male brook trout. They are known to prey on small bait fish and have been stocked in waters like Fish Lake where they also prey on tui chubs illegally released there.
ODFW net-setters last October discovered one tui chub, the first there since the lake was poisoned with rotenone in 2006 to kill off an estimated 90 million chub that damaged the lake's ecosystem and ravaged its historically excellent rainbow trout fishery.
The shiners have been documented in the lake the past six seasons and Huchko says there is no good estimate on their population.
All tiger trout must be released unharmed and this year's trout bag limit is down from eight fish per day to the standard statewide limit of five trout a day over 8 inches long, but only one may be more than 20 inches.
The trout were bought and shipped from a private Utah hatchery for about $20,000, Hutchko says. The cost was covered by a federal Sport Fish Restoration Fund grant of $13,000 plus about $22,000 raised by the Umpqua Fisheries Enhancement Derby, he says.
The leftover derby money will go toward the purchase of 15,000 more tigers and the same number of triploid sterile brown trout planned for stocking next year, Huchko says.
The agency also plans a stepped-up netting effort this summer on tui chub and shiners as well as creel surveys, Huchko says. This includes trap netting, electro-fishing and beach seines as well as a smolt trap near the Lake Creek outlet.