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Solar salt or Sea salt?

  • ‘Solar salt’ is the generic term for crystalline salts which are obtained by solar evaporation of seawater, salt lakes, natural brine, mined brine (solution mining) or brine that comes from an above-ground dissolution of rock salt.
  • ‘Sea Salt’ is crystalline salt which is extracted from seawater by solar evaporation. Production of salt by evaporation of seawater in natural lagoons or artificially created ponds, salt marshes or marine salt flats is one of the oldest processes. Salt marshes were mainly created near areas inhabited by ancient civilizations and on flat stretches of coastline. The principle has remained the same over centuries: seawater evaporates up to the saturation point in open basins due to the action of sun and wind.

Solar salt works are unique constructed ecosystems

Solar salt works are integrated constructed coastal ecosystems with a unique architecture. They consist of a system of shallow ponds connected mainly in series through which seawater flows, evaporates by the power of sun and wind, and deposits sodium chloride in crystallising ponds.

The exploitation of sea salt contributes to the development of biodiversity with fauna and flora specific to wetlands. The spatial organisation of the ponds and their different depths and salinity levels favour the development of a variety of micro-environments and microorganisms (algae, bacteria, molluscs, worms etc) which are attractive to a wide range of bird and fish species. This kind of habitats for communities of salt-tolerant vegetation and aquatic invertebrates are rarely found in other types of environments.

Shelter for wildlife

The microscopic pond life supplies food for a large number of waterbirds, some of which are endangered and protected. Certain species of birds, such as the Avocet, the Black-necked Grebe or the Kentish Plover, depend directly on the productivity of salt works, since their diet is exclusively based on brine shrimps. These shrimps are also part of the diet of the beautiful flamingos.

Salt works do not only provide key food resources for a wide variety of resident and migratory birds, but by their design, they also provide protection from predators and human disturbances. Vegetated dikes and islands within large ponds furnish birds with safe nesting and resting areas. Salt works with beaches closed for people provide undisturbed sites for sea turtles, seaside plants, fish nurseries and sea grasses.

Important economic value

Solar salt works are profitable ecosystems. Apart from salt production, solar salt works spur other types of economic activities. The rich avifauna present here attracts birdwatchers developing eco-tourism and supporting local economies. The brine and mud of the evaporating ponds are widely used for therapeutic and cosmetic purposes. Furthermore, solar salt works improve water quality and prevent flooding. 

More public awareness needed

The added value of solar salt works to biodiversity conservation and creation deserves broader public attention. While urbanisation and industrialisation have unfortunately severely altered the coastlines, salt works represent an important capital for the conservation of biodiversity. More supportive actions directed to this multifunctional activity are needed.

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