The Bidasoa is a river in the Basque Country of northern Spain and southern France that runs largely south to north. Named as such downstream of the small town of Oronoz-Mugairi in the province of Navarra, the river actually results from the merger of several streams near the villageErratzu, with the stream Baztan that rises at the north-eastern side of the mount Autza being considered the source of the Bidasoa. It joins the Cantabrian Sea between the towns of Hendaye and Hondarribia. facilities in Hendaye, Irun in the distance and the Santiago Bridge spanning the borderline The river is best known for establishing the borderline at its lower tract. This stretch is crossed not only by aircraft at low height but by important European communication axes, namely AP8 E5 E80 - E70 A63, main roads N1 - N10 and major French and Spanish railway networks,—RENFE and SNCF. Besides these major lines, other regional ones cross it too, e.g. regional railwayEuskoTren and another double bridge joining the towns on the border, i.e. the historical Santiago Bridge. At this stage of the river, urban landscape prevails. Before pouring its waters into the ocean, it forms a bay called Txingudi located between these towns and Irun, the site being designated Wetland of International Importance in 2002, with a total area of 1.28 km2. The banks of Hondarribia hold the minor San Sebastian Airport serving domestic flights and currently mired in controversy over its lengthening and upgrading scheme.
Pronunciation and etymology
The river comprises an area of linguistic contact, so it is pronounced differently depending on the language, namely in Basque, in Spanish, and in French. Linguistic and historic research point to the name stemming from Latin phrase "Via ad Oiassonem" on account of the road that linked at Roman times Basque town Pompaelo with Oiasso, which may have run along the river.
Course of the river and tributaries
The Bidasoa flows through much of its 66 km length over Navarrese territory, except for the last 10 km, where it establishes the borderline between France and Spain, as well as the boundary between the Basque provinces of Gipuzkoa and Labourd. In line with the distribution of the river's length, the bulk of its watershed's area lies on Navarre. The basin holds 105 permanent streams and rivers that number 497 km, the region being drenched in rains regularly. The Navarrese side of the basin is inhabited by 22,000 inhabitants. 70% of its population have the sewage treated before spilling to the river. But for the first 15-odd kilometres, the river clings to the north to south disposition of other neighbouring rivers of Gipuzkoa joining the Bay of Biscay, e.g. Urumea, Oria, etc. Strengthened by the waters harvested from the sides of the pass of Belate, downstream of Doneztebe the river heads north and crosses the town of Bera at the north end of Navarre before entering Gipuzkoa at Endarlatsa. From the town of Doneztebe on, the main road N-121 runs along till the roundabout across the river from the toll of Biriatu by the AP-8. Next comes the quarter Behobia and the major towns on the shores of the estuary. The main tributaries of the Bidasoa are the minor rivers Zeberia, Ezkurra, Latsa and Endara. Additionally, further small rivers and streams feed the Bidasoa all along.
Fishing and environmental challenges
The Navarrese tract of the river is a preferred destination for fishing enthusiasts, the river being home to several native fish species, namely eel, salmon, trout, bullhead, Barbatula barbatula, Phoxinus phoxinus, gudgeon, sea lamprey, allis shad, flounder and grey mullet, some of them declared endangered species and highly interesting. Moreover, a species of the Ebro, Chondrostoma miegii, has been introduced in the last 30–40 years on the lower tract of the Bidasoa, thereafter extending gradually upstream. As a result, overfishing has become a major problem for the river's fauna, with special pressure put on salmon migrating upstream to spawn. They do not make it to their goal and die before spawning, either falling prey to fishers' bait or an inability to overcome hydroelectric power stations and the 114 related dams, since 63% of them prevent migratory fish from achieving their purpose. Schemes by the Regional Government of Navarre are underway with a view to handling the issue.
