Homogenization of Fish Faunas Across the United States
Frank J. Rahel
*
Fish faunas across the continental United States have become more
similar through time because of widespread introductions of a group of
cosmopolitan species intended to enhance food and sport fisheries. On
average, pairs of states have 15.4 more species in common now than
before European settlement of North America. The 89 pairs of states
that formerly had no species in common now share an average of 25.2 species. Introductions have played a larger role than extirpations in
homogenizing fish faunas. Western and New England states have received
the most introductions, which is a reflection of the small number of
native fishes in these areas considered desirable gamefish by settlers.
Department of Zoology and Physiology, University of Wyoming,
Laramie, WY 82071, USA.
*
To whom correspondence should be addressed. E-mail:
frahel{at}uwyo.edu