199 



OTA REPORT brief 



Purple loos«stnte ILifthrum selcana) 



State by State 



spread of 



two harmful 



non-indigenous 



species 



Tfie Office of 



Technology 



Assessment 



is an analytical arm 



of the U.S. Congress. 



OTA'S basic 



function is to help 



legislators anticipate 



and plan for the 



positive and negative 



effects of 



technological 



changes. 



recorded. However, from 1906-1991, just 79 

 MIS caused documented losses of $97 billion, 

 mostly in control costs and losses of market- 

 able goods. A worst case scenario for 15 

 potentially high-impact NTS adds another $ 1 34 

 billion in future economic losses. This figure 

 likely represents only a fraction of the total 

 costs because many species and kinds of 

 effects are uncounted. Harmful NIS also have 

 exacted a significant toll on U.S. natural 

 areas, ranging from wholesale changes in 

 ecosystems to more subtle ecological alter- 

 ations. 



The rate of harmful introductions fluctu- 

 ates in response to social, political, and tech- 

 nological factors. This rate does not appear to 

 be increasing, although it is far higher than the 

 natural rate of introductions. The cumulative 

 number of foreign NIS in the United Stales, 

 however, is climbing steadily and swiftly — 

 creating an ever greater economic and envi- 

 ronmental burden. Just since 1980, ovei 200 

 foreign species were first introduced or 

 detected and at least 59 of these are expected 

 to be harmful. 



Uncertainty in predicting types and levels 

 of risk remains a problem. Past intentional 

 and accidental fish and wildlife introduc- 

 tions, for instance, have had about equal 

 chances of turning out badly. Uncertainty can 

 be reduced, or at least be made explicit, using 

 methods such as risk analysis, benefit/cost 

 analysis, environmental impact assessment, 

 and decisionmaking protocols. The central 

 issues for NIS and genetically engineered 

 organisms, a special subset of this group, are 

 the same: how to match an organism's poten- 

 tial for harm to pre-release scrutiny, how to 

 treat high-risk species, and how to anticipate 

 effects in new environments. 



AN OUNCE OF PREVENTION? 

 For some species, prevention is the best 

 strategy. However, port inspection and quar- 

 antine are fallible, with diminishing returns 

 above a certain point. Also, some organisms 

 are more easily controlled than intercepted. 

 So aiming for a standard of "zero entry" is 

 unrealistic, especially if prevention comes at 



