Document Type



Iowa fishes, biodiversity, non-indigenous fishes, nonnative fishes, exotic fishes, non-indigenous species, introduced species, exotic species, common carp, grass carp, bighead carp, black carp, silver carp, rudd, gizzard shad, yellow bass, mosquitofish, spotted bass, white perch, round goby, ruffe, Cyprinus carpio, Ctenopharyngodon idella, Hybophthalmichthys nobilis, Dorosoma cepedianum, Scardinius erythrophthalmus, Gambusia a/finis, Marone mississippiensis, Mylopharyngodon piceus, Hypophthalmichthys molitrix, Marone americana, Micropterus punctulatus, Gymnocephalus cernuus, Neogobius melanostomus


Since the time of European settlement, at least 59 non-indigenous fish species have been introduced, reached, or moved within Iowa waters. At least 28 nonnative fish species have been introduced into, or reported from Iowa waters since settlement. Of that number, 10 are established at this time through natural reproduction. In addition, many species of native fishes have been translocated within the state, and we provide documentation for 31 of these species. Two translocated species, gizzard shad (Dorosoma cepedianum) and yellow bass (Marone mississippiensis), have had adverse impacts on Iowa's aquatic ecosystems. While many introductions are thought to be benign, problems with non-indigenous fishes include displacement of native fish species, alterations of aquatic habitats, reduction in total aquatic biodiversity, and lowering of water quality. We review the history of Iowa's non-indigenous fishes, document the timing and location of introductions when possible, and discuss problems caused by Iowa's current non-indigenous species as well as species likely to cause ecological problems in the near future.

Fishes highlighted include: common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella), bighead carp (Hybophthalmichthys nobilis), black carp (Mylopharyngodon piceus), silver carp (Hypophthalmichthys molitrix), white perch (Marone americana), western mosquitofish (Gambusia alfinis), rudd (Scardinius erythrophthalmus), yellow bass, spotted bass (Micropterus punctulatus), ruffe (Gymnocephalus cernuus), round goby (Neogobius melanostomus), and gizzard shad. We also discuss ecological consequences of stocking game fish and hybrids as well as threats from aquaculture, aquarium hobbyists, and anglers. Because eliminating an established nonnative fish is almost impossible, we urge all parties to work to prevent future release and establishment of non-indigenous fishes in Iowa and the United States.

Publication Date

December 2001

Journal Title

Journal of the Iowa Academy of Science





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© Copyright 2001 by the Iowa Academy of Science, Inc.



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