Oca River, Biscay

Oca River
Marshland in the Oca estuary
Location
Country Spain
State Basque Country
Region Biscay
Physical characteristics
Mouth 
  coordinates
43°21′21″N 02°40′17″W / 43.35583°N 2.67139°W / 43.35583; -2.67139
Length17 km

The Oca river (Basque: Oka) is a river of the Cantabrian slope of the Iberian Peninsula that flows through the lands of Biscay, in the Basque Country (Spain).

The Oca river basin is the main part of the Urdaibai Biosphere Reserve, a protected area designated as such by UNESCO in 1984. Its naturalistic richness, especially ornithological, was a fundamental basis for this designation and for its declaration as a Special Protection Area for Birds (SPA) in 1994 and its integration into the Natura 2000 Network. In 1992, it was included in the list of Wetlands of International Importance of the RAMSAR Convention by decision of the Council of Ministers.

There are other rivers named in the same way; in Spain, there is the Oca river that runs through the province of Burgos and is a tributary of the Ebro. In Russia there is an Oká river that is a tributary of the Volga.