The Bay of Santander is both a ''

comarca A ''comarca'' (, or , or ) is a traditional region or local administrative division found in Portugal, Spain and some of their former colonies, like Brazil, Nicaragua, and Panama. The term is derived from the term ''marca'', meaning a "march, ...

'' of

Cantabria Cantabria (, also , , Cantabrian: ) is an autonomous community in northern Spain with Santander as its capital city. It is called a ''comunidad histórica'', a historic community, in its current Statute of Autonomy. It is bordered on the east ...

and the largest

estuary An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

on the North coast of

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

, with an extension of 22.42 km (9 km long and 5 km wide). Due to the influence of

Santander Santander may refer to: Places * Santander, Spain, a port city and capital of the autonomous community of Cantabria, Spain * Santander Department, a department of Colombia * Santander State, former state of Colombia * Santander de Quilichao, a m ...

and its metropolitan area, nearly half of the population of the autonomous community of Cantabria is gathered around it,Article from newspaper ''El Diario Montañés'
''El 50 por ciento de la población''
/ref> which makes the anthropic pressure on this area of water quite notable. The entrance to the bay is lined by the Sardinero beaches, where the Isle of Mouro with its

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lenses and to serve as a beacon for navigational aid, for maritime pilots at sea or on inland waterways. Lighthouses mar ...

can be found. The access to its interior is through a narrow channel of water between the Magdalena Peninsula, near to which are the Isle of the Tower and Horadada Island; and the sandbanks of the El Puntal, a long series of beaches and dunes that protect the tranquil inner waters of the bay. The morphology of the bay has suffered important changes in the last centuries. It is estimated that more than 50% of the original extension has been filled up, drying up a large amount of

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...

area for grasslands, to expand the

Port of Santander A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Ha ...

, and to create new industrial and residential areas. At the moment, work is going on to recover the seaside ecosystem in some areas of high ecological value.

Municipalities

The municipalities within the administrative comarca are as follows, listed below with their areas and populations:

Rivers and rias

Several rivers empty into the Bay of Santander. The most important is the Ria de Solía, in the South. The Ria de San Salvador empties in the center of the Bay via the Ria de Astillero while in the East flow the Rias of Carmen and Raos; to the West is the Ria de Cubas, which is the mouth of the Miera River.

Geology

The Santander Bay is formed by a

diapir A diapir (; , ) is a type of igneous intrusion in which a more mobile and ductily deformable material is forced into brittle overlying rocks. Depending on the tectonic environment, diapirs can range from idealized mushroom-shaped Rayleigh–T ...

generated during the alpinotype orogeny of the

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

period. Its materials are composed of

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

s and

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...

s (specially

Keuper The Keuper is a lithostratigraphic unit (a sequence of rock strata) in the subsurface of large parts of west and central Europe. The Keuper consists of dolomite, shales or claystones and evaporites that were deposited during the Middle and Late ...

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...

s) that ascended taking advantage of the faults. This movement generated an increase of the fracturing and an important dragging of rocks from the outer layers. The weakness zone generated by the Keuper's clays made easier its erosion compared with other

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

areas, which involved the advance of the sea and the formation of the bay.

Flora and fauna

*Common Tern ('' Sterna hirundo'')

References

External links

Live webcam of Santander BayHigh resolution live camera of the BayPictures of Santander and Cantabria, including Santander's bay

Report about the refill process of the Bay of Santander
{{Authority control Santander Bay

Green Spain Santander, Spain