The zone has an area of 23,870 square kilometres. The exact boundaries of the zone date back to treaties between what was then SFR Yugoslavia and Italy in 1968 and between Croatia and FR Yugoslavia in 2001. Prior to ZERP's declaration, Italian ships annually caught 300 million euros worth of fish from the zone - ten times the amount which Croatian ships caught. In its enactment of the zone, the Croatian Government also cited the danger of the Prestige oil spill being repeated on the Croatian Adriatic, which would seriously affect the country's tourism industry.