A number of macroinvertebrate species exist as important biotic factors in the Provo River. These include mayflies and caddis flies. Macroinvertebrates are an important food source for the many fish species, particularly trout, that live in the Provo River and its various tributaries.
Riparian and aquatic species of plants are important biotic factors in the Provo River ecosystem. Macroinvertebrates feed on the aquatic plants that grow in the river. Riparian tree species grow along the river banks and shade the river, keeping the water cool for fish and mammals. Riparian grasses and sedges also help to provide a buffer zone between the land and water, capturing potential pollutants and contaminants before they can get into the river itself.
The Provo River is known for its trout fishing and provides habitat for a number of species of trout. This includes common trout species like the rainbow and brown trout. Additionally, two threatened species, the Colorado cutthroat trout and the Bonneville cutthroat trout, both make their homes in the larger Provo River ecosystem.
Mammal and bird species act as the predators within the Provo River ecosystem. Raptors like bald eagles feed off of the river's fish species. Raptors also feed on smaller bird species that make their homes in the trees in the riparian zones surrounding the water. Mammals, such as the river otter, eat mollusks and aquatic plants from the bottom of the Provo River.
