The endangered and threatened fish fauna of the United States exhibits problems resulting primarily from habitat modification by man. The evolutionary history of the fauna has left it especially sensitive to biotic interactions. In addition, many forms are of such restricted distribution that the entire taxon can be destroyed by very minor perturbations. The effects of habitat modification on woundfin and roundtail chub in the Virgin River of Utah, Arizona, and Nevada are discussed. Parasitism by Lernea on White River springfish is shown to coincide with population decline in some, but not all, cases. Population declines of Pahrump killifish are related to biotic interactions with both goldfish and mosquitofish. Population size of Devils Hole pupfish are shown to be quite responsive to small changes in habitat availability.
Fishes of the West are affected by the same general kinds of ecological problems that are causing extinctions throughout the world. The interplay of the economics with perceived value in society has led us into the numerous ecological problems facing us today. There is some evidence to suggest that society is making some preliminary effort to slow the rate of extermination. Perhaps this is happening because the conclusions of ecologists, philosophers, and theologians regarding the relationship of man and environment are to some extent being translated into legislation as well as into conventional wisdom.
Deacon, James E.
"Endangered and threatened fishes of the West,"
Great Basin Naturalist Memoirs: Vol. 3
, Article 7.
Available at: http://scholarsarchive.byu.edu/gbnm/vol3/iss1/7