International organizations and large coastal nations often define the limits of a coastal area according to the particular coastal management issue being address; that is, the coastal area is defined according to the use to which that definition will be put, and the form of definition is termed ‘definition according to use’. For example, tackling the issue of non-point sources of marine pollution would require the definition of an area of attention that included inland catchment and groundwater outflow regions. A coastal area defined for this purpose would be much larger than one defined to manage four-wheel-drive vehicle damage of beaches and dunes.