lake trout

National Park Service

Yellowstone biologists are winning the war against invasive Lake Trout, and bringing back native Yellowstone Cutthroat.

Yellowstone Lake is a cold place. If you’re out on the lake even in the middle of the summer, you’ll need a jacket. So, when we went out in a boat with Yellowstone’s leader of the Cutthroat Trout restoration project, it was chilly.

Yellowstone Lake is the largest fresh water lake above 7000 feet in north America. It is also very deep, and cold. That is why non-native Lake Trout have thrived here. They evolved in the Great Lakes. 

A new study shows that the decline in native cutthroat trout has had dramatic impacts on the migratory elk herds in the Greater Yellowstone Area. 
 

Lead Researcher Arthur Middleton and others were studying the decline of elk herds in the region, and they determined that grizzly bears were playing a greater role in those deaths than they realized. 
 

The illegal introduction of lake trout into Yellowstone Lake has harmed the cutthroat trout population.