Regeneration of the dune ecosystem of Laida beach (Urdaibai) [ LIFE / NATURE / 000031 / ES ]

There are very few dune systems left on the Basque coast, though they used to be found wherever there was a beach. Over the past 200 years they have been reduced to a fraction of their former extension, and this has destabilised areas of beach and shoreline
where unique species now cling precariously to survival. The dunes of Laida and Laga are the only ones that have ever existed within the Urdaibai Biosphere Reserve. The Laida dunes survived up to the 1950’s, when they were wiped out by a major storm. Human pressure on the area (walking, sand removal, vehicles, etc.) increased from the 1960’s onwards, preventing dune plants from establishing themselves on the beach and thus increasing erosion and sand loss due to the action of wind and sea. One of the priority goals of the Reserve is to regenerate and conserve its natural ecosystems. At Laida social interests - preserving the beach for responsible recreational use - combine with environmental interests in restoring an ecosystem that vanished 50 years ago. The area of the estuary containing the Laida dunes is part of Location of EU Interest ES2130007 (Urdaibai Shoreline & Marshes) and Special Protection Area for Birds ES0000144 (Urdaibai River Estuary).

The 13.3 hectares of dunes in Urdaibai are the largest area on the Basque coastline, accounting for 41.3% of the total of 32.2 hectares of dunes classed as Locations of EU Interest in the Autonomous Community of the Basque Country within the Natura 2000
network. It is thus a very rare type of ecosystem that has suffered damage and is declining on the Basque coastline. The project to regenerate the dunes at Laida receives funding under the European Commission’s LIFE-Nature programme.

BEACH REGENERATION. Dune formation

Dune systems form a dynamic, fragile environment. Few ecosystems can change as quickly as dunes. For a dune to form naturally, three essential elements must be present:

  • Sand.
  • Wind capable of shifting it.
  • Space for it to build up.

The steps in which a dune forms are as follows

  1. The waves deposit sand on the shore. In time this sand builds up high enough to form a beach. Sun dried sand can be shifted easily by the wind.
  2. Regeneration work on the dunes at Laida is based on knowing how the shoreline system works. Dune regeneration work seeks to accelerate natural processes.
  3. Not all winds can shift sand: wind speeds of more than 16 kph are needed. The higher the wind speed, the more sand can be carried. In the absence of obstacles, the wind will erode the surface of sand dunes and return sand to the sea.
  4. Dune generation depends on obstacles such as shells, pebbles, logs, etc. that can block the force of the wind and cause fine sand to be deposited around them. Laida is subject to both north and south winds, and sand builds up around obstacles on both fronts. The wind only carries fine sand. Shells stay where they are and are gradually covered as dunes build up.
  5. The biggest obstacle that causes sand to build up into dunes is vegetation: plants catch sand under them and grow as the dune grows. As dunes form the range of species found on them increases and different environments are generated. Fixing plant life stabilises dunes in general and consolidates the beach against natural erosion.

LAS DUNAS EN EL AMBITO DE LA COSTA VASCA (PDF, 400 KB)

REGENERACION DE PLAYAS. La formación de las dunas (PDF, 392 KB)

FUNCTIONS OF DUNES

Coastal dunes have many functions that often go unnoticed.

Did you know that

  • dunes consolidate beaches, prevent sand loss, encourage sand build-up and protect the shoreline;
  • stabilising dunes prevents sand from being carried into the estuary silting it up, thus saving on environmental costs and financial costs of dredging;
  • dunes diversify the uses of beaches by providing more private spots sheltered from the wind and encouraging relaxed recreational pursuits such as nature watching in all the seasons of the year;.
  • dunes grow in length and width, thus extending the area of beach available for public use and providing large recreation areas; they also considerably increase the area of beach available to sunbathers and swimmers;
  • dunes make for a more diverse, attractive, natural landscape on the shoreline;
  • dunes provide a valuable habitat for many endangered species, and one that we all have a responsibility to recover.

LAS FUNCIONES DE LAS DUNAS (PDF, 359 KB)

DUNE PLANTS

Dune ecosystems are scarce on the Basque coast, and are therefore essential conservation areas for many protected local plants. They are the most inhospitable coastal habitats because of their changeability, their poor substrate (sand), their high salinity and their exposure to the wind and waves.

Dune plants have developed various ways of surviving in this harsh environment. Most of them have fleshy leaves where what little water than can retain is stored. They have adapted to withstand the impact of wind-blown sand and even partial burial. some of them, such as the European beach grass (Ammophila arenaria) are natural sand traps, and their life-cycles are closely linked to that trapping process. Others, such as the beach morning glory (Calystegia soldanela) develop beautiful flowers on the surface and run out an underground network of roots that stabilise dunes and make them more consistent. A few years after the commencement of this project to regenerate the dunes at Laida there is a clear recolonisation by the species that formerly populated this shoreline. The first to appear were the searocket (Cakile maritima), the Russian thistle (Salsola kali) and the sea knotgrass (Polygonum maritimum), which formed the beginnings of dunes.

Later, in the shelter of the beach grass and couch-grass other plants developed, including Honkenya peploides, the sea holly (Eryngium maritimum), the sea spurge (Euphorbia paralias) and the lovely sea daffodil (Pancratium maritimum). Spring 2004 saw the appearance of the first saltcedars (Tamarix gallica). Aside from natural environmental circumstances such as wind, storms off the sea, etc. the main threat to these fragile plants are being trodden on and being engulfed by exotic invading plants that compete with them for spaces on the dune faces.

LA VEGETACIÓN DE LAS DUNAS (PDF, 415 KB)

THE INHABITANTS OF THE DUNES

Coastal dunes have long been breeding grounds for some species of birds. Regrettably, the small size of the dunes and sand bars remaining in the Autonomous Community of the Basque Country and the pressure exerted on these areas in the breeding season by human beings mean that there are no longer any nesting grounds there. One of the most interesting potential dune nesters is the little ringed plover, which is classed as a “vulnerable species”. The oystercatcher certainly also nested on our shores in the past, when they were wilder and more secluded.

Just as occurs with plants, many of the animals that live in dunes are rare, interesting and surviving only precariously. Insects with many different survival strategies live on the dunes: the digger wasp (Philantus triangulum) is a wandering predator that preys on insects as big if not bigger than itself, such as the honey bee. The dune tiger beetle (Cicindela hybrida) is another predator of the dunes. Special mention must be made of the ant lion (Myrmeleon formicarius): this strange insect builds funnel-shaped traps in the sand and lies in wait at the bottom to capture ants which slide down into the funnel.

The dunes are also home to reptiles such as the three-toed skink, one of the jewels in the crown of dune fauna. This harmless reptile, which looks similar to the blindworm, has vestigial forelimbs with three digits. In winter seals from northern Europe have also been detected in the area.

The coastal dunes are also important resting stopover points for some species of migratory birds in spring and autumn.

LOS HABITANTES DE LAS DUNAS (PDF, 379 KB)

SAND CONTAINS THOUSANDS OF DIFFERENT SUBSTANCES

Sand is a sedimentary substrate produced as the sea erodes the shoreline. The type of stone found in each area of shoreline determines the type of sand on each beach. Foraminers are another highly interesting group. These microscopic animals are used as bioindicators. Foraminers from the open sea have been detected in the sand at Laida. This confirms that the sand on the beach there originated in the sea, as the result of continued erosion by the sea of the rocks that form the coastline. The sea hurls pebbles and shells against the cliffs, breaking them into ever finer fragments and thus forming sand.

These tiny fragments are carried by the current and deposited in sedimentation serious, i.e. on beaches. In Urdaibai most of the beaches comprise medium and fine grained sand, although some coves are made up of coarse sand or even pebbles. Along with inert materials such as quartz, feldspar, rock splinters and fragments of shell , the sand contains huge numbers of microscopic invertebrates. Of these, the sand mites are especially interesting: their job is to metabolize what little organic matter remains in the sand and convert it into energy that can be used by plants.

LA ARENA CONTIENE MILES DE ELEMENTOS (PDF, 427 KB)

WHAT CAN YOU DO?

The project to regenerate the dunes at Laida needs your help. The success of this project depends on everyone complain with a few basic rules of behaviour.

Remember the following points and we will all be able to enjoy a more attractive, larger beach and live in harmony with the dunes and their inhabitants.

  • Do not go beyond the perimeter of the dunes.
  • Remember that the dunes are still being formed, and walking on them may do serious damage to plant life.
  • Do not pull up plants on the dunes.
  • Remember that most of these plants are protected species. All plants are important, so respect them.
  • Unauthorized vehicle access to the beach is prohibited.
  • Camping is prohibited.
  • Do not dump refuse on the dunes.
  • Please remove any litter that you may produce (cigarette ends, plastic bags, organic waste, etc.) and place it in a bin.
  • Comply with the signposts on the beach.
  • Use only the marked pathways through the dunes.

El proyecto de regeneración de la duna de Laida requiere de tu colaboración (PDF, 669 KB)

PROJECT

The project arose as a result of the worrying situation at Laida beach in the mid 1990’s, when more than half it’s surface area had been lost. After an analysis of the situation, a pilot scheme was drawn up to observe the mechanism of sand accumulation on this beach. The basic idea was to restore Laida beach by regenerating its dunes so as to recover the ecosystem lost 50 years ago.

It was set up at the north-western end of the beach. Sand traps were set up and the pilot scheme area was enclosed with wildlife-friendly fencing to prevent it from being walked on. The results confirmed that the beach could once again contain a major dune system capable of stabilising and consolidating it.

  • Sand trap barriers were placed over the tips to prevent sand loss and establish the first stage of regeneration of the dune system. Over this time an area above the tide line of around 10,000 m2 was stabilised and around 7,000 m3 of sand was trapped. A dune height of around 7.5 m was attained.
  • Once a given volume of sand had been trapped, characteristic sand trapping plants were planted. In this case the species used were European beach grass and sand-couch grass.
  • A perimeter fence was set up to discourage entry into the regeneration area and prevent the sand from being trodden on.
  • Monitoring & sediment assessment of the project were conducted by scientists from the University of the Basque Country and the Urdaibai Biosphere Reserve itself.
  • Sand from the dredging of the estuary was tipped on the site to bring it back into the system and accelerate dune regeneration.
  • From 2003 onwards, new sand traps were installed in several areas selected following studies of prevailing wind patterns.
  • In June 2004 225,000 plants were planted on the regenerated areas.
  • In the summer of 2004 an information and environmental education campaign was begun, aimed at users of the beach and inhabitants of the municipalities that lie within the Reserve.

PROYECTO DE REGENERACION DE LAS DUNAS DE LAIDA (PDF, 396 KB)

ACTIVITY REPORTS

Scientific monitoring

This research is conducted under the UNESCO Chair in Sustainable Development and Environmental Education in the framework of the Urdaibai Biosphere Reserve. 

Environmental education

2004 saw the beginning of an information campaign which continued in July, August and September 2004, 2005 and 2006.

An exhibition was set up at Laida beach and in the nearby towns and villages. Local towns and villages were also provided with a range of informational material including leaflets, comics & puzzles.

PHOTOS

VIDEOS

Last modified date: 12/05/2017