Risk Assessment of Marine Biological Invasions

Risk assessment has proven a useful tool in managing potential hazards in business and industry. Environmental hazards however, have proven to be less tractable to quantitative assessment. Here we discuss the application of risk assessments in the context of marine biological invasions and provide a summary of the progress to date in the Australian context. Risk assessment for marine biological invasions is being applied to aid in the management of ballast water using a target species approach assessed in discrete elements of the ballast water cycle (uptake, transit survival, and discharge). Risk assessments for marine bioinvasions provide another tool to aid managers in controlling and reducing the rate of current invasions. In contrast to a blanket ban on ballast water imports (i.e. mandatory ballast water exchange at sea), a risk-assessed approach can provide a mechanism to better understand the invasion problem and determine better operating procedures, high-risk routes or system failures (e.g. false reporting of ballast exchange, incomplete or inadequate exchange). Similarly, risk assessment can aid in the process of management strategy evaluation to determine what components of the invasion process are more susceptible to control, or more apt to fail under specific management regimes