Yellowstone biologists gain upper hand on lake trout

MAMMOTH HOT SPRINGS, Wyo. (KIFI/KIDK)-Over the past 20 years, Yellowstone National Park has invested over $20 million to recover the native cutthroat trout population.

Key to the effort has been the removal of non-native lake trout from Yellowstone Lake. After this year's campaign, park officials report a declining lake trout population. Park and contract crews removed 282,960 fish between May and October compared to 297,110 in 2018 and 396,950 in 2017. That is a 29% decline over 3 years.

"I want to personally thank the National Park Service team, our partners, and the many people who have philanthropically supported this continuing conservation effort," said Superintendent Cam Sholly. "There is a considerable amount of work yet to do to build on this progress. This will continue to be one of our conservation priorities."

Since lake trout were first discovered in 1994, more than 3.4 million of the predator fish have been removed through suppression gill-netting. It is one of the largest non-native fish removal programs in the United States.

While lake trout decline, long-term monitoring indicates a substantial increase in the number of cutthroat trout in the Yellowstone Lake ecosystem.

Fishery scientists estimate that a minimum of five more years of effort is needed to reach the lake trout population goal of below 100,000.

"The park will never completely eradicate lake trout but the return on investment is the ecological restoration of Yellowstone cutthroat trout, sustainable angling, and a chance to glimpse a river otter, osprey, or bear catching a cutthroat," said Dr. Todd Koel, leader of the Native Fish Conservation Program.