Declared a Biosphere Reserve by UNESCO in 1984, the Urdibai estuary became the first protected natural area in Euskadi. Later, in 1989, the Basque Government passed the Urdaibai Biosphere Reserve Protection and Use Law. As protected areas, Biosphere Reserves form part of an international network, which thanks to scientific research and integrated management of the respective territories, allows closer study of the workings of world-wide ecosystems.