Bay of Biscay

The Basque Bay of Biscay (in Basque, Bizkaiko golkoa; in French, golfe de Gascogne) is a wide gulf of the North Atlantic Ocean located in the western part of Europe. It extends from Cape Ortegal in Galicia (Spain) to the tip of Pern on the island of Ouessant, in Brittany (France). It bathes the coasts of the Spanish autonomous communities of Galicia, Asturias, Cantabria and the Basque Country, as well as the French regions of New Aquitaine, Pays de la Loire and Brittany.

In Spain, the Bay of Biscay is considered the easternmost part of the Cantabrian Sea, which designates the coastal sea that bathes the north coast of Spain and the southwest coast of France and which would correspond to what the Romans in the century I a. C. named as Sinus Cantabrorum ("Bay of the Cantabrians"). The northernmost part was called Sinus Aquitanus or Mare Aquitanicum (sea of the Aquitanians).

Physical geography

Its southern coast is steep, with a multitude of cliffs between which beaches and small bays open up, generally at the mouths of rivers (which are usually in the form of estuaries). The tidal flat of the Gipuzkoan coast stands out, between Deba and Zumaya (which extends to a lesser extent as far as Ondárroa), and the beaches of Gijón, Llanes, Santander, Laredo, Comillas, Laga, Deba, Zarauz or San Sebastián, while the French coast is straight, low and sandy, with dunes and numerous marshes, from the south to the mouth of the Loire; in the northern third, on the Brittany coast, there are alternate rocky and elevated stretches, with numerous inlets, bays and wide sandy beaches.

The rivers that flow into the southern coast of this gulf are short, like all those on the Cantabrian slope. On the other hand, those on the east coast (Garonne that flows into the city of Bordeaux or Loire) have a long route, returning to being a short course to the north (in Brittany). Among the Spanish, the Nalón stands out, being the longest and mightiest river in the Spanish area, the Nervión, which forms the Bilbao estuary, and the Bidasoa, which partly marks the border between France and Spain.

The Christmas current is the warm surface waters that flow along the Atlantic coast of the Iberian Peninsula from south to north and the Cantabrian coast from west to east, until colliding with the French continental coast to move north. The months of November to March. in a strip approximately 50 km wide.

The strong south-westerly winds that generate it originate from low pressures centered over the British Isles and the North Sea, combined with the Azores anticyclone.

This current is to blame for part of the spillage of chapapote or galipot from the Prestige shipwreck reaching the French coast from beyond the city of La Coruña in Galicia.

Regarding bathymetry, the Bay of Biscay has two continental shelves separated by a wide abyssal plain with a maximum depth of 2,789 m. This plain was created by the separation and rotation of the Iberian plate with respect to the Eurasian plate. The boundary between both platforms is defined by the Capbreton Trench, a narrow submarine fjord 2,100 m deep and 150 km long that approaches in front of the port of Capbreton, in the French department of Landes.

This bathymetric arrangement and the northwest orientation of the Bay of Biscay make it especially exposed to storms from the North Atlantic. The narrowness of the continental shelf in the southern part means that the waves can reach a considerable height on this coast, especially in front of the Capbreton Trench.

Biological geography

The Bay of Biscay fishery is similar to that of the Cantabrian Sea. It is heavily exploited and there are many species that are in serious danger of extinction, such as sea bream, hake and even anchovy. Others, such as mackerel and bonito, are in good health and are regularly exploited. Some species have already disappeared from the Bay of Biscay, such as the glacial right whale, the last specimen of which was hunted in Orio at the beginning of the XX century. However, it is a good region for observing marine mammals.

Human Geography

Lighthouse and beach of Biarritz (Atlantic Pyrenees, France).

Since ancient times, the Bay of Biscay has been an important shipping transit area. The characteristic of its location and shape has encouraged its use for navigation between the western continental coast and the north of the peninsula, and between these points and the British Isles (unlike the western region of the Cantabrian Sea, the Galician and Asturian coasts, where routes to and from Ireland were encouraged). There are regular ferry services between Bilbao and Portsmouth, Gijón and Nantes, and between Santander and Plymouth.

Includes important commercial ports, such as Avilés, Gijón, Santander, Bilbao, Pasajes, Bayonne (France), Bordeaux, La Rochelle, Nantes or Lorient, and fishing ports such as Vivero, Burela, Luarca, Cudillero, Candás, Llanes, San Vicente de la Barquera, Santoña, Laredo, Castro-Urdiales, Bermeo, Ondárroa, Guetaria, San Juan de Luz, Les Sables-d'Olonne or Concarneau.

International Hydrographic Organization (IHO) delimitation

The highest international authority on sea delimitation, the International Hydrographic Organization (IHO), considers the Bay of Biscay to be a sea. In his world reference publication, "Limits of oceans and seas" (Limits of oceans and seas, 3rd edition of 1953), he assigns it the identification number 22 and defines it as follows:

A line that unites Corporal Ortegal with the western end of Ouessant (punta de Pern) through this island to the eastern end of the same (Lédénès) and from there, to the East, on the 48o28 parallel' N to the coast of Brittany.

Limits of oceans and you are, p. 9.