Storms drag sand from the beach out to sea. This is a natural phenomenon. However, due to the increased number and intensity of storms, it is important to help the beach reverse erosion. Pals Beach is home to an important line of dunes, currently the most effective resource for tackling sea-level rise. Our dune protectors are facilitating their preservation through various stabilisation days and the creation of sand traps.

The collective imagination tends to associate dunes with extreme temperatures and arid, waterless climates. But examples as popular as the Great Dune of Pilat, Rooted in the maritime and forested environment on the Aquitaine coast in south-west France, it defies expectations. Pals Bay is the setting for a singular phenomenon: the extensive coastal dune.

Many of Catalonia's rivers have their source on the peaks of the Pyrenees. The slope of the surfaces down which the first waters flow accelerates their speed and favours the erosion of the initial rocks. Along its course, all the terrain it traverses is transformed by this effect, and the tiny fragments that break away are carried along by the current.

As the slopes lose their gradient, the new landscape morphology facilitates the widening of the riverbed and the reduction of river velocity, causing a small proportion of its sediments to begin depositing on its banks. Usually, the flow remains strong enough for the sluggish yet steady currents to reach the sea.

And so the Ter and the Fluvià complete their journey into the bays of Pals and Roses, discharging their waters and the well-rounded pebbles, until they release a great army of tiny particles between 0.5 and 2 mm in diameter, which we can now popularly call beach sand.

—

The coastal dune is that great mass of sand that never stays still. A special ally of the tramuntana and the gari, it has reshaped the appearance of the Empordà coast over the centuries, coexisting, not without friction, with both locals and visitors in the area. In the Middle Ages, it covered the heritage inherited from the first great civilisations; later, it invaded arable land until the ingenuity and effort of the local population stabilised it with extensive pine plantations. In the mid-20th century, in the midst of the Cold War, about its latent state, it became one of the station's foundations Radio Liberty, the most powerful broadcaster in the world. At the same time, the most important socioeconomic phenomenon of the century was born: tourism, one of the main aggravating factors of its regression.

YOUR GRAIN OF SAND MATTERS

The artificialisation of the coast jeopardises the dynamism of beach–dune systems and their capacity to recover after storm events. Maritime storms erode the dune front, which naturally regenerates during periods of calm seas. Dune systems are particularly important for slowing the advance of the sea and beach erosion in a context of rising sea levels and intense storms..

Currently, some of our rivers do not contribute the same volume of sediment as in past eras. Furthermore, the installation of new port infrastructure on the seafront alters the currents that had shaped our beaches as we know them. Thus, the combination of various factors affects the longitudinal transport of sand along the bay, causing some areas to accumulate less sand in both length and volume.

That is why, recently our group of Dune protectors, making use of the branches and logs brought to the coast by various storms, has carried out a day of sand trap construction. These traps consist of low-profile mesh lines, several metres long, designed to retain wind-driven sand grains, thereby aiding the restructuring of eroded dunes on the foreshore.

Below, we explain the construction process step by step.

Sand Traps

The activity stretched four dune threads totalling 16 metres of trap length, ready for the wind's generosity to increase their volume and for various herbaceous species, such as borro, to take root there and better stabilise the sinuous distribution of the sands. The flora and fauna of the dunes constitute a very exceptional habitat on the peninsular coastline and in the Mediterranean basin, with a a high degree of rarity and a high threat. For this reason, the Natural Park safeguards its protection by cordoning off the area and preventing foot traffic and overcrowding by people and domestic animals. This is especially important during the nesting season from March onwards. Kentish Plover, which lays its eggs in the sand. Once these formations have reached a sufficiently large size, the markers will be advanced towards the sea to ensure, as far as possible, their gradual reconstitution.

We are very keen to observe the progress of our intervention to promote the re-establishment of dunes on the seafront. At present, we are scheduling further workdays, taking advantage of the low level of human activity and heavy cleaning machinery during this time of year, which makes it easier to collect plant fibre debris of varying sizes.

Rebuild your beach

Do you want to know a little more?

We find ourselves facing a landscape of delicate aridity. According to the European Union Habitats Directive, dunes are habitats of community interest and some of their habitats are considered priority. Dune formations are dynamic areas of high ecological, biological, geological and landscape value, constantly subject to natural and anthropogenic disturbances. On our coastline we can distinguish between white dunes and grey dunes. During this day we have been restoring a white dune.

The White Dune

Also known as an embryonic mobile dune, it is found at the foot of the beach, protected behind dunes to prevent trampling due to its fragility and composed of very few elements other than sand and plant fibre debris. In Pals Bay we enjoy this treasure.Unique in Catalonia for its size, where botanical species of moderately deep, easily drained sandy soils and variable slopes grow, such as the sea rocket –Cakile maritima-, –Medicago marina-, the morning glory Calystegia –Calystegia soldanella-, the sea holly -Eryngium maritimum-, the sea spurge -Euphorbia paralias-, the’Stachys maritima and the precious sea lily –Pancratium maritimum-. The dunes and interdune areas with natural non-nitrophilic vegetation constitute a priority habitat of community interest, specifically in the closed area of Radio Liberty occupy an area of 16 hectares, and 14 hectares in the rest of the municipality outside the dune area.

We also find mobile dunes fixed with the European beachgrass –Ammophila arenaria–, just in front of the fence of Radio Liberty, in the area closest to the sea, with unique botanical species, such as Elymus farctus, the sea holly -Eryngium maritimum- and the Echinophora spinosa which covers an area of 1 hectare.

The Grey Dune

Also known as a fixed coastal dune, It is best represented on the seafront at Radio Liberty, covering an area of 13 hectares. Here the mobility of the sand decreases and it tends to compact; they are called grey dunes because of the significant contribution of organic matter to the soil, which forms a thin humic layer. They harbour communities of Crucianella maritima, botanical species such as cat's claw stand out. -Ononis natrix subsp.- and the shaggy sparrow-wort –Thymelaea hirsuta- , and shrubby species of calcareous and siliceous scrub such as the Tamarix Ramosissima, the the Spanish lavender or topped lavender –Lavandula stoechas-, the rosemary -Rosmarinus officinalis-, the grey-leaved cistus or white-leaved rock-rose -Cistus albidus-, the sage-leaved rock-rose -Cistus salviifolius– and Ephedra distachya. Also of note is the marine variety of the St John's Wort flower –Helichrysum stoechas var. maritimum-, the Tuberous Hawk's-beard –Aetheorhiza bulbosa-, Carex arenaria, or the Fringed Pink -Dianthus hyssopifolius subsp-.

All photographs by © Kait Hutchison.

Date of article creation: 24/2/2025.

WE DO NOT LET OUR GUARD DOWN

If this information has been forwarded to you and you like it, subscribe here.