Analysis of farmed fish movements between catchments identifies a simple compartmentalised management strategy for bacterial kidney disease in Scottish aquaculture

The movement of live fish between fish farms has been identified as a critical risk factor in the spread of disease yet these movements are an essential part of fish farm production cycles. Bacterial kidney disease (BKD), caused by Renibacterium salmoninarum, is a disease which affects farmed salmon and trout production, although the impact on trout is considered less serious than on salmon. It is therefore desirable to minimise the exposure of salmon to R. salmoninarum. The approach presented here shows the potential for the salmon and trout industries to be split into two separately managed compartments in terms of control of spread of BKD by live fish movements. This compartmentalisation system is supported by the low number of cross compartment movements with only six out of 207 active farms in compartment S (mainly salmon) receiving fish from a farm located in compartment T (mainly trout). ► Live fish movements have been identified as a risk in the spread of BKD. ► We analyse movements of live fish between the salmon and trout industries. ► Low cross compartment movements support a compartmentalised management strategy. ► Principles developed have provided advice to policy makers. ► A new disease control strategy for BKD has been implemented.