- An invasive species found in Yellowstone is the Lake trout fish
- An invasive species is a non native species that causes problems such as decreasing a different population
- The Lake trout is decimating the native Cutthroat trout population in the Yellowstone lake.
- The lake trout carry a disease called the Whirling disease
- The whirling disease is caused by microscopic parasites that cause the cutthroat trout to not feed normally