Modelling biosecurity change: Ecology, economics, technology and social values

The threats and responses to biosecurity are constantly changing, creating decision problems for policy makers setting priorities for future biosecurity systems. In the United Kingdom during 2003–04, the Department for Environment, Food and Rural Affairs (DEFRA) commissioned a Horizon Scanning project to predict the future (20–30 years) of biosecurity needs in the United Kingdom. This project created an integrated model of key ecological, economic and technological processes involved in the development and control of invasive species, across a range of taxa, and also sought views on social values that could limit response options and affect the economic and political importance of introduced species. The model demonstrates the ability to make useful probability- based estimates of economic impact given practical assumptions on ecological, economic and technological inputs. Sensitivity analyses show where improved data could reduce uncertainty. The model establishes a framework that has been used to identify major drivers of biosecurity change affecting the next generation: increased and more diverse trade and travel increasing the entry of new species; climate change affecting establishment and spread of pests introduced from new zones that could approximate Britain’s climate; social values affecting attitudes to control measures such as animal culling and greater concern for environmental and amenity resources rather than agriculture; and technological improvements in pest detection. An important economic issue affecting the value of the impact caused by invasions is the time scale over which the impact is felt, ranging from immediate in the case of many livestock diseases through to the long-delayed recognition of loss of environmental quality from competition or diseases affecting native plants. New pest detection technology offers substantial opportunity to improve eradication of introduced species and could affect the prevention versus cure paradigm for many species for which general exclusion systems are presently adopted. An integrated modelling framework allows some quantification of these drivers and offers a tool to guide biosecurity planning.