The Asian Clam (Corbicula fluminea) was introduced into the United States in the 1930's, and now they are found in nearly every major watershed in the United States. Asian Clam and the Zebra Mussel (Dreissena polymorpha) are dissimilar to native mussels because they require no intermediate fish host for reproduction and are capable of reproduction in mass quantities. The Buffalo River was found to have increasing densities of Asian Clams and these growing populations were highest within sites with physical habitat disturbance and poor water-quality. At these locations the diversity of surrounding macroinvertebrate communities is decreasing and resource managers are trying to understand the mechanisms involved in the interactions between the aquatic insects and the Asian Clam.
In 1995 the largest sighting of feral hogs on the Buffalo National River was reported, a herd of 35 hogs was observed in the Lower Buffalo Wilderness Area. Feral hogs have been released into the park from numerous sources in the last 2 decades, and now hogs range up and down the whole river corridor. The increasing densities of feral hogs are a problem due to the impacts they have within the river corridor and tributaries from their rooting and foraging activities.
Other impacts include the decimation of rare plant communities that occur in springs and seeps, and negative interactions with native wildlife. Some other nonnatives species found in Buffalo National River include Kudzu, Mimosa, Garlic Musturd, Spotted Knapweed, Tall Fescue, Sericea lepidezia, Johnson grass, and numerous other species.