Assessment of consequences of notifiable fish disease incursions in England and Wales

A consequence assessment framework was developed to evaluate the economic and environmental consequences of an exotic disease in the context of supporting policy level decisions on mitigation strategies. The framework adopted a semi-qualitative analysis of impacts supported by expert judgement. The efficacy of the framework was illustrated via assessment of the notifiable fish disease, Gyrodactylus salaris. In this example, the economic cost of an illustrative outbreak of G. salaris ranged from £0.22 million to £90 million. The cost of the most likely scenario (regional spread) was estimated to be £7.5 million (minimum to maximum range of £2–22 million), reflecting the uncertainty in the extent of spread of the parasite before detection. The environmental impacts vary by a factor of 35 between incursion scenarios reflecting the number of affected catchments in the scenarios.