Uncertainty in risk/benefit assessment for proposed biological control agents

Abstract: In New Zealand applications for new biological control agent introductions include
a risk/benefit analysis that is submitted to the Environmental Protection Authority NZ (EPA) to be evaluated and considered for approval. A sample of recent applications, along with the EPA evaluation reports were examined for expressions of uncertainty (EoUs) relating to the
identification and assessment of risks and benefits. This study was carried out with the aim of
informing future research priorities that might be able to address and reduce uncertainty and
hence support more robust decision-making in the future. Twenty applications received by the EPA between 2009 and 2019 were examined for EoUs, using examples of biocontrol agents proposed for both weed and insect targets. As expected, uncertainty about likelihood of direct non-target impacts along with indirect food web effects was frequently identified, but some EoUs were less predictable. Māori consultation is a critical to the EPA application process, and particular note was taken of uncertainties relating to concerns about risk to cultural values. Recent changes to the risk assessment process have been made which requires that evidence of risk to Māori values will be given more prominence in the future. For uncertainty relating to benefits, many case studies mentioned efficacy, establishment and spread of the proposed biological control agent, and uncertainty about benefits to cultural values. Several questions were also raised about the method of cost: benefit analyses that had been presented in the application. Recommendations for future research were identified from the analysis.