Four types of fish that frequent the Colorado River and Lake Powell are officially endangered because of the construction of dams and introduction of non-native species: the razorback sucker, Colorado pikeminnow, humpback chub and bonytail.
In addition to the above, Lake Powell is naturally home to the bluehead sucker, flannelmouth sucker, roundtail chub and speckled dace.
The National Park Service introduced three types of bass specifically for fishing purposes: the smallmouth bass, largemouth bass and striped bass.
Other non-native species have been introduced into Lake Powell with the intent of challenging fisherman. These include walleye, rainbow trout, channel catfish, bluegill and black crappie.
Though almost all non-natives are damaging to native ecosystems, the gizzard shad is causing many problems to the native and non-native fish populations because of its large size. The fish has spread throughout the lake and have no natural predators.
