BESTNet/ecoSERVICES workshop on the economics and ecology of biological invasions: developing a synthesis of ecological and economic research on the biological risks of growth in world trade

09.00 – 09.45 Charles Perrings (ASU), William Brock (WisconsinMadison), Ann Kinzig (ASU) and Margherita Gioria (ASU), Globalization and invasive species The widening and deepening of international trade has had a number of environmental consequences, of which the most significant may well be the redistribution of species. There are two processes involved. The opening of new markets or trade routes has resulted in the introduction of new species either as the object of trade or as the unintended consequence of trade, while the growth in the volume of trade along existing routes has increased the frequency with which introductions are repeated. At the same time, the probability that an introduced species will establish and spread depends both on the characteristics of the species and on the vulnerability of the host system. More disturbed, less diverse systems are more vulnerable. We focus on the first process. The risk of introductions is increasing in the volume of trade, each unit of trade being regarded as a sample from the potentially invasive species in a source country. We model the problem and show that the existence of invasion risks of trade reduces both the socially optimal level of imports and the socially optimal level of harvesting effort. Evidence for the impact of traderelated invasion risks is presented and evaluated.