4.4 Biosecurity and zoning strategies

Disease is probably the main threat and cause of disaster to aquaculture everywhere and requires planning at all scales, from individual farms to aquaculture zones and aquaculture management areas. The development and implementation of biosecurity and zoning strategies is increasingly recognized by countries and industries as essential to sustainable growth in aquaculture (Håstein et al., 2008; Hine et al., 2012).

The World Organisation for Animal Health defines a zone as a portion of a contiguous water system with a distinct health status with respect to certain diseases; the recognition of zones is thus based on geographical boundaries.
A zone may comprise one or more water catchments from the source of a river to an estuary or lake, or only part of a water catchment from the source of a river to a barrier that effectively prevents introduction of specific infectious agents. Coastal areas and estuaries with precise geographic delineation may also comprise a zone. For more detail on zoning and spatial planning from the biosecurity perspective, see Annex 2.