Abstract
Ecological risk assessment (ERA) is a tool used in the development of management plans for fisheries. These plans are a means for implementing an ecosystem approach to fisheries (EAF) that is now the global paradigm in fishery management. EAF requires fisheries to be managed within the context of their ecological, social and economic relationships. Therefore, the risk to the sustainability of all three of these spheres from the potential impacts of fishing activities needs to be assessed. The risk assessment of the ecological components of an ecosystem, including target species, bycatch and byproduct species, habitats, species assemblages and ecological processes is the focus of this review. The paper reviews, in a marine fisheries context, the methods used to estimate ecological risks and highlights essential aspects needed for any approach for estimating ecological risk in marine fisheries. A generalized risk-assessment framework consists of three parts: risk context, risk identification and risk characterization. The estimation of risk levels occurs in risk characterization. Quantitative and qualitative methods have been developed to estimate risk in fisheries. Quantitative methods, such as stock assessments, focus on target species. With the introduction of an EAF, there arose a need to assess the potential impacts to sustainability of all ecological components that can be affected by a fishery. Qualitative ecological risk-assessment methods were developed for this purpose. Diverse methods have largely been driven by differences in the legislative requirements of different countries. An overview of the methods currently in use for ERA is given and the principles they use to estimate risk is discussed. In particular, four Australian hazard-exposure methods are reviewed as these constitute the main qualitative methods developed so far. Eleven essential elements needed for any method for estimating ecological risk in marine fisheries are identified.