Welcome to Les Salines, a combined marvel of nature and human ingenuity!
Salt pans occur naturally in many parts of the world, and people have harvested the valuable resources for centuries, so it’s not surprising to see these pans artificially created in coastal areas to farm this commodity. At Tamarin there is a large manmade salt terrace complex, spanning two separate locations. You can make your observations from the roadside at either location, or better yet, take the tour and hear for yourself all about the history here. Please note, only the primary site is still in operational status, but while the secondary site is no longer producing salt, it still offers good observation.
(Salt terraces seen from above)
The salt cycle
If you’ve ever been in the sea, you’ll know it’s salty, and this is the primary factor behind farming salt on terraces such as Les Salines. The process is relatively straightforward, but certain factors help ensure an efficient operation and high quality end product.
Step 1. Flooding the terrace.
At Tamarin, the salt terraces are slightly inland from the ocean (approximately 100m) and stretch several hundred metres farther inland, so pumps are used to extract sea water, and then flood the individual fields to a uniform depth of 3cm.
Step 2. Evaporation.
To separate the water from the salt, evaporation is used. With year round hot weather and lots of sunshine (7-8 hours per day average), the climate is well suited to evaporate the water and leave behind the salt.
Step 3. Harvesting.
Once the water has completely evaporated, the harvest can begin. Workers manually brush the salt crystals into piles, which are then transferred to storage sheds to completely dry out, then be packaged.
Significant factors.
Several factors contribute to make Tamarin a great location for salt terraces.
Factor 1. Proximity to the ocean.
Without a guaranteed supply of clean, fresh, sea water there would be no raw product to farm.
Factor 2. Rock type.
Local basalt is typically impermeable (unless fractured) which makes it ideal to use as a base for pools, since the water will not drain away. This ensures the saline solution stays in place while the evaporation occurs. It is also easy to work into small, flat bricks with lightly grained surfaces, which allow for easy harvesting of the salt by brush.
Factor 3. Rock colour.
Local basalt is very dark grey or black in colour, which ensures optimal absorption of heat from the sun, and in turn makes the evaporation process quicker and more efficient.
(Abandoned salt terraces at alternate observation site)
Recent problems affecting salt production.
The salt terraces at Tamarin are under pressure from two significant challenges. The first is pressure from external markets offering a lower quality product at a much cheaper price. The second is climate change. New weather patterns in Mauritius can result in less sunlight, and more humidity, both of which make the salt farming process less efficient due to reduced heat and the potential for more rainfall.
Required tasks to log this earthcache:
- Describe the type, shape ,and texture of the rocks used to line the pools in the terrace. Why are these elements important in the salt production process?
- Describe the depth of the pools and explain why this matters in the process?
- What colour are the rocks and do you think this is a significant factor in the efficiency of the process?
- What effect do you think climate change could have on future production of salt at Tamarin?
While not required, photos are always appreciated. Please enjoy your trip to Les Salines and thanks for visiting!