Gulf of Morbihan

Geography

The gulf is long 20 km and broad 15 km. It opens on the Baie of Quiberon by a narrow passage between Locmariaquer and Port-Navalo and is made up many splits, points, rocks, and islands and small islands.

Formation

The gulf receives water of three principal rivers: that of Auray, Valves and Noyalo. A third of the surface of gulf (that is to say 40 km ²) consists of mudholes which are discovered with low tide. The geological origin of the gulf of Morbihan goes back to the quaternary era, following the cycles of glaciation, when the rivers dug an excessively deep estuary to join the ocean which had been withdrawn further. At the time of the thaw, the gulf consisted of marsh whose bottom subsided and the ocean ends up invading the basin. This phenomenon is not single with the gulf of Morbihan, even if its particular form is due to the presence of an offshore bar composed of more resistant rocks. At the time of the last phase of thaw, the gulf did not have the same extent as that which one currently knows. It is considered that the sea level rose from 4 to 5 meters compared to the period of the first prehistoric habitats.

Currents and tides

The gulf is separated from the Baie of Quiberon in the Atlantic Ocean by the Presqu'île of Rhuys and communicates with this one only by one narrow narrow part one kilometer broad between the points of Port-Navalo (commune of Arzon) and of Kerpenhir (commune of Locmariaquer). So one meets there very strong currents of Marée, sometimes giving to certain tightened passages paces of torrents. The sea enters and leaves the narrow part of Port-Navalo at a speed which can reach nearly 8 nodes (4 m/s). What makes of it the second running most extremely of Europe. The current of the mare, between the Island of Berder and the Île of the Mare can even reach 9,4 nodes.

The cycle of the tides is shifted compared to that of the ocean and knows a great inertia: thus, when the tide is high in Baie of Quiberon and at the entry of the gulf, the bottom continues “to fill” and the level to be gone up there. There thus exists a shift between the hour of full sea in the entry of the gulf and the hour of this one in the content of the gulf. The tide is high with Vannes one hour forty approximately five after the hour of full sea with Port-Navalo. Moreover, there exists a shift between the hours of tides at the entry of the gulf and in bay of Quiberon: the full sea with Port-Navalo is half an hour after the full bay sea of Quiberon. The opposite phenomenon is observed naturally at the time of the low tide. In addition the current ceasing being in the direction “going up” when the water level in the content of the gulf reached its maximum, at certain hours, one can observe a decreasing water level with Port-Navalo whereas the gulf continues to fill and thus the current being in the “rising” direction. Moreover, the currents of flood (flow) and ebb (backward flow) are not regular but interact inside the gulf, creating many counter-currents.

Islands of the gulf

The gulf is strewn with many islands (from 30 to 40 according to the calculations) and small islands. The Breton legend allots of it however a number even more raised, by claiming that there is as much as days in the year. The gulf would have been created by the tears of the driven out fairies of the forest of Brocéliande. The fairies would have then thrown their crown there which would have become the islands. Only two islands have a notable surface and a population: the Island with the Monks and the island of Arz. They are communes, many other islands being private properties.

Navigation in the gulf

These characteristics, added to the rather low depth in certain parts of the gulf, make necessary a careful navigation. Nevertheless the Pleasure sailing is very developed in the gulf. Indeed, the number of splits and recesses make particularly difficult navigation in the gulf. Reference marks make it possible to sail as the pink house which makes it possible to find the access to the river of Vannes.

Several port S of pleasure offers services more or less developed with the yachtmen: wearing of Valves which offers all the range of the port services to more modest dampings of Arradon, of the island to the Monks, Port-White, the island of Arz and Port-Navalo (nonexhaustive list).

The Center-board S and boards with veil are very active them also and of many schools of veil courses and hirings propose.

These ten last years, the gulf saw the explosion of navigation in more or less powerful motor boats. An association of dissatisfied residents tries to make limit to 5 nodes engine navigation and request with the public authorities to make comply with the rules of navigation which suffer from many infringements. More generally, a growing number of in love with the gulf deplores the pollution sound and maritime pulled by the multiplication of the motor boats.

Traditional boats

Certain villages of fishermen developed sailing S which is clean for them:

the Sinagot S of the name of the village of Senna, fishing vessels to fish, generally to two fore-and-aft sails
Pirates of the Bono.

Moreover, in all the gulf, flat-bottomed boats, the “punts are used”, for the fishing and the breeding of the shells and transport in the parts of the gulf where there is not very basic.

the Cheetahs, punt in " V" gulf of Morbihan of 5m50 (traditional construction wood).

Fauna and flora

The mudholes and the marshes of the gulf supported the development of a varied ecosystem, in particular by the presence of an herbarium of Zostère, the more important second of France. It contributes to stabilize the grounds, to decrease the turbidity of water, to support oxygenation, the production of the Phytoplancton and constitutes a natural shelter for the reproduction. The Academy of the littoral acquired a portion of the marshes of Senna, in order to protect them.

The gulf is especially famous for its ornithological interest . In addition to the gulls and the seagulls, it is one of the places of migratory in cash richest France, of which it accommodates between 60.000 and 130.000 individuals during the winter season:

Barnacle S
Duck S: Wigeon, teal, Duck mallard, Tadorne de Belon.
Waders: barge, ashy sandpiper, héron, white spatula, Brush garzette, ibis crowned

Prehistory

The gulf is an enthralling zone for the study of the Préhistoire and more particularly of the Neolithic time , as from 7500 years before our era. One finds there many monuments megalithic:

Menhir S
Dolmen S
Cairn S or Tumulus: constructions hones some not built being used to shelter death chambers. Most known is that of the island of Gavrinis, broad of 60m. At the time of its construction, the site was not isolated, it became an island only at one relatively recent period.
a double Cromlec' H out of horseshoe on the small island of er Lannic. It is a double enclosure of raised Mégalithes and partially immersed. At the time construction of the southern enclosure, the small island was connected to the shore. This site is a remarkable witness of the rise of water.

See in reference the publication: " The er lannic" site megalithic; of Philippe gouezin and Eric Gall. 1992 Association " Archéo Douar Mor" ; Terrestrial and subaqueous archaeological studies with land surveys of the site. 1991.1992 Scientific report/ratio. DRASSM.

Economy

The economy of the area of the gulf developed around the Agriculture and of the Ostréiculture, plus an industrial pole around Vannes. Nowadays, it is directed more and more towards the Tourisme. The maritime event of the Semaine of the Gulf organized every 2 years since 2001 in is an good example.

Fish and Ostreiculture

It is logical to gather these two activities in the gulf of Morbihan, because they are often carried out jointly by the same owners. Since the sailors gave up old the sinagots with the yachtmen, fishing is carried out either with small trawlers, or with flat-bottomed boats, the punts , adapted to place and raise the racks and to visit the oyster beds. One fishes in particular mule, Rouget and Coquillage S. fishing with foot exists, also practiced by the amateurs. It formerly constituted an important additional source of revenue for farmers located close to the littoral.

The activity most developed and adapted to the gulf is the Ostréiculture, with an annual production of 450 tons, mainly directed towards the production of seed oyster (young people oysters).

Tourism

Tourism developed considerably during the last decades, bringing its economic basket and its batch of pollution and disturbances for the natural environment.

The landscapes of the gulf are attracting, in spite of a rather flat relief. Omnipresent nature offers a subtle mixture of sea, marsh and moors. Coastal paths, one can observe the migratory birds and benefit from the variety of points of sights offered by the many islands.

Connections in the maritime high-speed motorboats serve the most visited places, and propose circular walks to discover them, in particular the island with the Monks and the island of Arz. The ports of Valves and Port-Navalo (commune of Arzon) are also landing stages to go to the islands Houat and Hoëdic in the close ocean.

The architectural heritage also contributes to the attraction of this area, with the Château of Suscinio, remains dukes of Brittany, the Romance abbey of Saint-Gildas-with-Rhuys, Auray and the old port of Goustan Saint, without counting the cairn of Gavrinis and the old city of Vannes.

The infrastructures developed consequently, and number of second home appear in periphery of the coastal villages. The vacation centres and the camp-sites are mainly located on the oceanic side of the peninsula of Rhuys, but near the gulf. With Arzon close to the old Port-Navalo in the Années 1980 was built the Port of Crouesty, true seaside resort which can shelter 1000 pleasure boats and has a center of Thalassothérapie. This initiative was discussed for its artificial aspect, even if architecture tries to be integrated in the coastal landscape. One can however consider that tourism in Morbihan remains turned as much towards nature and the gulf that towards the beaches of the very close ocean.

See too

Bordering communes

The Breton toponym possible is indicated between brackets.

Arradon
Arzon
Auray ( Year Alre )
Baden
Bono
Hézo
Island-in Arz
Island-with-Monks ( Izenah )
Larmor-Baden
Locmariaquer ( Locmariaker )
Noyalo
Plougoumelen
Saint-Armel
Saint-Gildas-with-Rhuys
Sarzeau ( Sarhau )
Senna ( Sine )
Theix
Valves ( Gwened )

The communes of Island-in Arz of the Island-with-Monks are not located on the circumference of the gulf, but on islands in its center.

Islands and small islands

The orthography of the small islands can vary according to the sources; the terms used here are those being reproduced on the charts of the national geographical Institut. The Breton name of the toponyms is possibly indicated between brackets.

Island of Arz ( enez Arh )
Île Bailleron
Île of Berder
Île of Boëd
Île Boëdic
Île Brannec
Île of the Charles
Cohty
Île of Conleau
Corn Bihan
Îles of Brouel
Île Creïzic
Denten
Dervenn
Île Drenec (as well as the two small islands of Drenec will vras and Drenec vihan)
Enézy
er Lannic
er Runio
Gavrinis
Île Godec
Island Govihan
Large Huernic
Hent Tenn
Island Holavre
Island Ilur
Island Iluric
Inézic
Island of Irus
Island of the Mare ( er gazeg )
Island of Lerne
Large Logoden ( Logodenn will vras )
Petit Logoden ( Logodenn vihan )
Long Île ( Enez to hir )
Île of Mancel
Île with the Monks ( Izenah )
Île Mouchiouse (or Mouchot)
Île of the Eggs
Île with the birds
PEN Bleï
Island Piren
Island Pladic
Island of the Point
Island Quistinic
Island Radenec
Reno Island (or Renaud island)
Seven Islands (actually, only one island)
Stibiden Island (“chébdenn decides”)
Île Tascon
Île Trohennec
Grand Veïzit
Petit Veïzit

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