What is the Sillon de Talbert?
The Sillon de Talbert is a 3.2 km long by 35m wide strip of sand and pebbles that juts into the sea.
A geological curiosity and a site of ecological interest, it is also the northernmost mainland of Brittany.
The Sillon de Talbert is located in the municipality of Pleubian, at the tip of the peninsula delineated by the vast estuaries of the Trieux and Jaudy.
It protects the coast from sea erosion and from the waves during spring tides.
It also shelters the waters of the Ile de Bréhat from strong currents.
Twenty thousands years ago the sea level was 120m lower than today.
Extreme sub-zero temperatures caused the break-up of granitic rocks and the formation of pebbles.
The warming climate then triggered the melting of the glaciers and the rising of the sea levels.
Currents generated by the phenomenon broke the rocks and reduced them into stones.
They pushed them towards the coastline, where they became blocked by boulders and accumulated in long strips.
These strips were progressively displaced with the rising of the sea levels and eventually settled in their current location.
A unique land listed as Réserve Naturelle Régionale
The formation and location of the Sillon de Talbert turn it into a unique site.
It is indeed home to exceptional fauna and flora which, however, suffer from a precarious status, as the thin sandy strip undergoes continual erosion.
Various plant species that thrive on poor soil are therefore protected.
The fauna is also largely represented by marine nesting birds which lay their eggs in the pebbles.
Their eggs blend into the pebbles and are a perfect example of adaptation to the environment.
Number of migratory and wintering birds such geese and sandpipers knights also settle on the Sillon for the winter.
They feed on the mud flats and rocky reef at low tide.
The unique structure of the Sillon de Talbert turns it into a geological curiosity and a site of prime ecological interest.
As a result it was registered Réserve Naturelle Régionale du Sillon de Talbert in 2001.
This area extends over 18 hectares and is one of five nature reserves in Brittany.
This network consists of natural or semi natural sites located in the European Union.
Evolution of the Sillon de Talbert
The Sillon is under constant observation.
The first mapping surveys conducted in 1666 show how its shape has changed since.
It used to link the Ile d’Ollone to the mainland until the 18th century, when a strong storm opened a breach.
Other breaches appeared and closed again over the years and the southeast side is receding.
The Sillon’s length has shortened in the last 40 years and its tip is changing shape.
The Conservatoire du Littoral observed that the channel located between the Ile Blanche and the Sillon, which was 60m wide 50 years ago, is now almost closed!
Large granite blocks protect the Sillon’s north side.
However, many of these blocks are submerged in shallow waters and present a real danger to navigation.
The best known of these reefs is the Epées de Tréguier where the Héaux de Bréhat lighthouse – which marks the entrance to the Bay of St-Brieuc – was built.
The use of pebbles as building material largely contributed also to the Sillon’s fragility.
An official decree of 1907 therefore put an end to the exploitation of pebbles.
The Germans, alas, resumed the exploitation during WWII in order to build their bunkers along their Atlantic Wall.
Finally, after the war locals were exceptionally allowed to pick up large pebbles three days a year in order to rebuild their homes.
Strengthening the Sillon de Talbert
The collection of large pebbles, necessary to the stability, strength and resistance of the Sillon, eventually became a major issue.
The alarming evolution and change of shape of the Sillon led the department to undertake consolidation works in the 1970s.
However, the huge granite blocks put in place to protect the Sillon had a counter-active effect.
They indeed prevented its natural flexibility and thus weakened it further!
On June 11, 2001 the management of the site was therefore delegated by decree to a panel of experts grouped in the Conservatoire du Littoral.
Decision was made to allow the Sillon to:
“regain its natural flexibility and thus its reactivity against the natural phenomena that had built it and regulated it by removing and crushing the blocks of granite and displacing them.”
With time the Sillon de Talbert will recover stability and resistance it needs to survive!
Along the Sillon de Talbert
A nature trail runs along the ridge and allows you to discover the Sillon.
You’ll see tractors collecting seaweeds on the beach; they have replaced the boats and carts locals once used.
For over 10 centuries seaweed harvesting was indeed very active on the Sillon de Talbert.
Farmers dried the seaweeds on the beach then dehydrated them in furnaces installed on the ridge.
Modern day harvest methods are not as picturesque but they are still interesting to watch.
Department of Côtes d’Armor
Coordinates: Lat 48.866951 – Long -3.101710