Skip to main content
U.S. flag

An official website of the United States government

Invertebrate community data from native trout lakes and streams in the Southern Rocky Mountains

October 30, 2020

Native trout in the West suffer a high degree of vulnerability, as highlighted by cutthroat trout, a group of 14 subspecies, most of which have been petitioned for listing under the Endangered Species Act (ESA). In the Southern Rocky Mountains, greenback cutthroat trout (Oncorhynchus clarkii stomias; GBCT) are listed as threatened under the ESA, and few populations remain, in part because of the invasion of nonnative fishes (for example, brook trout, Salvelinus fontinalis). In an effort to restore GBCT to their native range, chemical treatments (piscicides) are often used as a tool to remove nonnative fishes prior to reintroducing native fish. However, the influence of the piscicides on nontarget organisms, such as benthic macroinvertebrates and zooplankton, is not well understood. It is important to fill this knowledge gap because the success of reintroducing native fishes is related to the overall functioning of streams and lakes, which includes stable fish prey assemblages. This multi-year dataset identifies and quantifies the invertebrate populations in three separate areas of interest within the native GBCT range with GBCT restoration potential.