Invasive bait fish called the tui chub have returned to Diamond Lake again, most likely brought there by rainbow trout fishermen using live bait fish.
To rid previous tui chub invasions, wildlife officials poisoned the entire lake twice, the last time in 2006. This time around, they are stocking the lake with tiger trout, a sterile cross between brook and brown trout. The idea is for the tiger trout to eat the chub minnows.
The lake abounds with natural trout food. Unchecked, the chubs become the top predator in the lake and eat the trout food, which results in fewer trout and blooms of blue-green algae that clogs shorelines with a dangerously toxic, green sludge.
Diamond Lake is naturally fish-free. No lake fish are native, but the lake has been stocked with trout since the early 20th century. Some ecologists say the money spent on keeping trout fishermen happy at the lake could better be spent on native fish restoration elsewhere.
The Oregon Department of Fish and Wildlife says Diamond Lake sports fishing has generated about $15 million in economic activity since the last chub invasion 10 years ago.
Source: Burns, Jes. "Oregon Battles Invasive Minnows to Protect Non-Native Trout." Jefferson Journal 40 (Sept-Oct. 2016): 6-10. Print;
