Personal tools

You are here: Home / Presentation / The study area of ZABrI / The islands and beaches

The islands and beaches


The Iroise island system includes the uninhabited islands of the Mullein Archipelago and three inhabited islands: Molène, Ouessant and Sein.

A declining population and changing activities in the islands

The total population in the islands, presently about 1,500 people, declined by two thirds in the 20th century, while the mainland coast, some 300 kilometers, has a population of about 75,000, and a growth rate similar to the average growth in coastal areas on the French mainland. Since the 1920s, the islands have seen a significant shift in the use and occupation of land, linked to a sharp decline in the human population. Over time, the islanders have practically abandoned agriculture, while the service sector has kept growing in response to an increasing number of tourists. As agro-pastoral activities decline, landscapes become more and more closed, entailing considerable changes in terms of accessibility, visibility and biodiversity. On the continent, the progressive abandonment of agricultural activity along the coast, the development of road infrastructure and the appeal of coastal living have led to urban sprawl.


Varied landscapes

The diversity of island landscapes is reflected in a mosaic of beaches, cliffs, coves and archipelagos, which are subject to the violence of winter storms and sea spray, as well as to tidal variations. The beaches of the Iroise Sea consist of fine to coarse sands, which come from the mobilisation of the submarine sediment deposits and the erosion of the granite and metamorphic rocks along the coast.

Fluvial contributions to the island beaches are nonexistent, as the Aulne and the Elorn carry fine soil particles that settle to the bottom of the Bay of Brest. The evolution of the beaches is mainly modulated by the following two forcing factors: marine erosion and human frequentation.