Netting operations on Yellowstone Lake have yielded higher numbers of both invasive lake trout and cutthroat trout, leading officials to declare progress in the battle to save native species.
Cutthroats once ruled in Yellowstone Lake, but the introduction of lake trout and whirling disease have greatly diminished their numbers. The solution: an aggressive netting program, as well as regulations requiring fishermen to keep the brown trout and release the cutthroat.
Todd Koel, Yellowstone’s supervisory fisheries biologist, said the numbers are proof that the park’s aggressive methods are showing returns.
“Age 2 and age 3 fish represent a large percentage of the cutthroat population, which we haven’t seen in around a decade,” he said. The fish spawn when 3 to 4 years old. “We haven’t necessarily won the battle, but it’s a good sign.”
The netting operations this summer have so far removed 275,000 lake trout from Yellowstone Lake with another three weeks of work yet to go. That compares to 224,000 netted last year and 150,000 in 2010.
The netting is funded by the National Park Service, assisted by a $1 million grant from the Yellowstone Park Foundation.