Our Livliifi Kcxdiine.'i — Non-ihirivc Species 



431 



References 



Carlton. J.T. 1479. Introduced invertebrates of San 

 Francisco Bay. Pages 427-444 in T.J. Conomos. ed. San 

 Francisco Bay: the urban estuary. American Association 

 of the Advancement of Science. Pacific Division. San 

 Francisco. CA. 



Carlton. J.T. 1991. Man's role in changmg the face of the 

 ocean: biological invasions and implications for conser- 

 vation of near-shore environments. Conservation 

 Biology 3(3):265-27.1 



Courtenay. W.R.. and J.D. Williams. 1992. Dispersal of 

 exotic species from aquaculture sources, with emphasis 

 on freshwater fishes. Pages 49-81 in A. Rosenfield and R. 

 Mann, eds. Dispersal of living organisms into aquatic 

 ecosystems. Maryland Sea Grant. College Park. 



McClelland. M. 1992. Invasion of the hio-snatchers. Florida 

 Environments 6(2):5,I3. 



Meyers, J.H.. C. Higgins. and E. Kovacs. 1989. How many 

 insect species are necessary for the biological control of 

 insects? Environmental Entomology I8:541-.'i47. 



Miller, R.R.. J.D. Williams, and J.E. Williams. 1989. 

 Extinctions of North American fishes during the last cen- 

 tury. Fisheries l4(6):22-38. 



Mills. E.L., J.H. Leach, J.T. Carlton, and C.L. Secor. 1993. 



Exotic species in the Great Lakes: a history of biotic 



crises and anthropogenic introductions. Journal of Great 



Lakes Research 19( I );I-.'i4. 

 SFL 1994. Sport Fishing Institute releases repoil on eco- 

 nomics of sport fishing. Sport Fishing Institute Bull. 



452:6. March/Apnl 1994. 

 U.S. Congress, Office of Technology Assessment. 1993. 



Harmful non-indigenous species in the United States. 



OTA-F-.'Sfi.'S. U.S. Government Printing Office. 



Washington, DC. 391 pp. 

 Wildlife Nurseries. Inc. 1989. What brings them in. 



Catalogue of animals and plants for wildlife habitat. 



Oshkosh, WI. 

 Williams. J.D.. M.L. Wanen, Jr., K.S. Cummings. J.L. 



H;ims, and R.J. Neves. 1993. Conservation status of 



freshwater mussels of the United States and Canada. 



Fisheries l8(9):6-22. 

 Williams. M.C. 1980. Purposefully introduced plants thai 



have become noxious or poisonous weeds. Weed Science 



28(3):300-305. 



For further information: 



Richard Sayers, Jr. 



U.S. Fish and Wildlife Service 



1 849 C Street, NW, Mailstop 



ARLSQ-820 



Washington, DC 20240 



Within the United States alone, humans 

 have intentionally or unintentionally 

 intioduced mote than 4,300 species of tenestri- 

 al and aquatic species to areas outside their his- 

 torical range (U.S. Congress 1993). Although 

 many terrestrial introductions are viewed as 

 beneficial to humans because of economic and 

 social considerations, all but a few intentional 

 aquatic introductions have proven to be mixed 

 blessings (Courtenay and Williams 1992; 

 Steirer 1992; U,S. Congress 1993). No uninten- 

 tional aquatic introductions have been consid- 

 ered beneficial (Steirer 1992); instead, their 

 environmental consequences are generally 

 hannful and sometimes catastrophic (Taylor et 

 al. 1984; U.S. Congress 1993). 



Both intentional and unintentional introduc- 

 tions have enabled nonindigenous fish to 

 become temporary, and often pemianent, resi- 

 dents in neariy every U.S. aquatic system. 

 Complete eradication or exclusion is neither 

 economically plausible nor socially justified 

 (U.S. Congress 1993); therefore, nonindigenous 

 fish are and will continue to be components of 

 these aquatic systems. Because nonindigenous 

 fish have the potential to alter significantly the 

 U.S. aquatic ecosystems during the next centu- 

 ry and beyond, their interactions within the 

 aquatic community must be monitored and ana- 

 lyzed to ensure that effective management 

 actions are taken before a crisis arises. 



To help document the consequences of non- 

 indigenous fish introductions, the National 

 Biological Service monitors the status and dis- 

 tribution of these organisms in U.S. waters 

 (Williams and Jennings 1991). Since 1978, 

 reports and specimens of various nonindigenous 

 fish have been collected, verified, and entered in 

 a geographic information system, which is a 

 computerized mapping and data base system. 



Obtaining qualitative and quantitative infor- 

 mation on nonindigenous fish for a national 

 assessment requires cooperation by many agen- 

 cies, organizations, and individuals (Boydstun 

 and Benson 1992). We collect much of our eco- 

 logical and geographical data using a voluntary 

 reporting form. Historical accounts are gathered 

 through review of both scientific and other liter- 

 ature, including natural resource agency publica- 

 tions that often provide accounts of nonindige- 

 nous fish, stockings, and discoveries. For our 

 purposes, we established a historic cut-oft' date 

 for usable nonindigenous fish reports at 1800. 



We limited this analysis to only reports of 

 nonindigenous fish from open waters identifi- 

 able to species level and recognizable non- 

 indigenous hybrids. 



Status of Nonindigenous Fish 



We have collected more than 1 1,000 reports 

 that document 404 unique fish species or 

 hybrids introduced outside their native ranges 

 within U.S. waters. This diverse group of 67 

 families of fish includes species from every 

 continent except Antarctica. Of the 404 species, 

 252 (62%) are native to the United States but 

 found outside their native ranges, and 152 

 (38%) are from other countries. Nonindigenous 

 hybrid fish represent roughly 5% (19) of the 

 total 404 nonindigenous fish species. 



Our total is considerably higher than the 1 27 

 nonindigenous fish (70 U.S. and 57 non-U. S.) 

 reported in the United States in 1992 by the 

 Office of Technology Assessment (U.S. 

 Congress 1993). Courtenay and Williams 

 ( 1992) reported 99 exotic (non-U. S.) nonindige- 

 nous fish species in the contiguous U.S. waters 

 in 1992. of which 46 were established as sus- 

 taining populations. The di.sparity between our 



Nonindigenous 

 Fish 



by 



Charles Boydstun 



Pain Fuller 



James D. Williams 

 National Biological Service 



