Laguna Salada de Torrevieja

"Torrevieja's  fortunes turned around at the beginning of the 19th century when the then King of Spain, Carlos IV, ordered salt production to be transferred to the Torrevieja lake from the nearby La Mata lagoon. Torrevieja prospered and is now home to more than 100,000 residents, including many foreign expats who have set up home here.

The park is about 3,700 hectares.The pink lake is 1,400 hectares and the green one is 700 hectares. Both are connected to the sea by canals. 

The strange pink-purple colour of the Torrevieja lagoon is caused by pigments of the Halobacterium bacteria which lives in extreme salty environments. This is also found in the Dead Sea and the Great Salt Lake. The colour is also caused by an alga called Dunadiella Salina, which is responsible for the bright red colour of the lake seen at certain times of the year. The Artemia Salina brine shrimp, which lives in the lake, is also red because it feeds on the bacteria. You will also see the flamingos turn a lovely shade of pink because they eat the shrimps. The salt is produced from the south-east corner of the pink lagoon.

Production tends to take place when Torrevieja starts to heat up in June and ends in October. The process begins when the sea water is carried to La Mata lagoon. The salt lake is four metres below sea level which is enough to open the gates of La Mata canal to let the water pass through. As it reaches the green salt lake, the water starts to evaporate. At this time, the water contains about 30g of sodium chloride (common salt) per litre. After the water evaporates, the salt level rises to about 150g per litre. At this point, the water is carried to the Torrevieja lagoon, where the salt level soars to about 300g per litre. It is at this key moment that the process of crystallisation takes place and the salt starts to solidify at the bottom of the lake. Now it is collected.

At one time, this was done manually with one worker hitting the salt to break it up and another loading it into a boat. Nowadays, a special machine does the work. The machine, which looks similar to a tank, moves through the lake lifting the salt and loading it on to a conveyor belt. This carries it to barges waiting at the side of the lake. Paddle boats – similar to Mississippi river boats – act as tugs to drag the barges on to an artificial island the middle of the lake. The salt is unloaded on to another conveyor belt and washed several times to get rid of any impurities such as clay. After this, it is taken to the side of the lake and deposited into large salt mountains.

The pyramid shape prevents rain water from washing away the salt as it simply runs off the sides. The salt is then split into different categories and sizes depending on its final use. Altogether, there are 14,000 different uses for salt including making glass, PVC manufacture, and in the textile, chemical and pharmaceutical industries. It is also used to de-ice the roads.

The Torrevieja salt is moved directly to the ships by conveyor belts linked to the ports so it can be exported abroad. Norway is the main importer while Italy, Portugal, UK, USA, Ireland and Denmark are also major users. Within Spain, Torrevieja salt is sent to Galicia for use by food companies and to Catalonia and the Basque country. Nowadays, the Torrevieja lakes produce 700,000 tonnes of salt a year and is still a very important industry for the Alicante region.

The current leaseholders has guaranteed salt production until at least 2039 so it will continue to be a profitable business for the area. As part of the agreement, the company has also agreed to invest in environmental improvements and to help promote the salt industry as a tourist attraction. Visitors can learn about the history of these amazing lagoons in an interpretation centre, which proudly boasts that the Torrevieja salt industry is one of the most important throughout Europe."

From http://www.spain-holiday.com/Alicante-province/articles/alicantes-pink-and-green-salt-lakes