Fish

Originally, the Gunnison River supported native fish and aquatic insects in its clear, oxygen-rich waters—which start from snow melt on the western slope of the Continental Divide. After the Bureau of Reclamation built three dams on the Gunnison River from 1961 to 1978, the fishery of the river changed.

Before the dams, the Gunnison River water temperature would generally rise slowly from spring to summer, then decrease again for fall, and stay low during winter. Cool temperatures were preferable for native fish species. Presently, the dams release water from the bottom of the reservoirs. This is where the coldest water exists. When the water flows downstream to Black Canyon, its temperature is overall colder than pre-dam times.

Colder water, altered flows, and competition from non-native fish may all contribute to the lack of native fish species found in the park.

 

Non-native Species

Non-native species do not occur naturally in an area and are introduced as the result of human activities. Non-native fish species in Curecanti are present due to stocking programs and accidental or illegal introduction. Two non-native species are commonly found in Black Canyon: Rainbow trout and Brown trout. Both these species are “trophy” trout – meaning they are heavier, longer, or otherwise remarkable in some way.

 

Rainbow trout (Oncorhynchus mykiss)

Rainbow Trout

Rainbow trout (Oncorhynchus mykiss), were introduced into the Gunnison River in the 1880s, are stocked quite heavily and can be caught in river areas or the reservoirs. Identifying marks are black spots on a light body and a colorful red stripe along the sides.

 

Brown trout (Salmo trutta)

Brown Trout (German)

Brown trout (Salmo trutta) is another large fish species which can be found in the Gunnison River. They can be difficult to catch outside their fall spawning run. Their bodies have a spotting pattern composed of black and red-orange spots to help distinguish them from rainbow trout or cutthroats.