In an annual report issued yesterday, entitled Yellowstone National Park Natural Resource Vital Signs
, the National Park Service detailed the current progress of efforts to reduce the population of non-native fish species within the park. These efforts are specifically geared towards reducing competition with the park's native fish species, Westslope Cutthroat Trout and Yellowstone Cutthroat Trout, hopefully allowing the populations of these species native to the park's ecosystem to expand. According to the report, current efforts to remove non-native species of fish within the park are proving ineffective. In fact, populations of some non-native species have even increased, despite efforts to the contrary.
The situation concerning Yellowstone Cutthroat Trout (YCT) in Yellowstone Lake continues to be a struggle. In fact, the number of YCT caught per mile during sampling efforts reached an all-time low of 5.3 in 2010, after peaking at nearly 20 YCT per mile in the early 1980s. Managers attribute this continued decline to predation by nonnative lake trout, whirling disease and the effects of low water conditions in recent drought years. Unfortunately, despite the removal of over 550,000 nonnative lake trout during the last decade and a half, perceived populations of lake trout continue to rise.