Lake Rose in Senegal loses its color

Lake Retba, also called Lake Rose, is a must-see during a trip to Senegal. It is also one of the two most visited tourist sites in the country. Unfortunately once again the intervention of man is getting the better of this little “pink candy”. Let's see why?

Presentation

About thirty kilometers from Dakar, on the Cape Verde peninsula, Lake Retba is known around the world for its pink color. It was for a long time the finishing stage of the Paris-Dakar, which contributed to its fame. Since then, people have come to see him from everywhere. more than 5 centuries old, it was once inhabited by crocodiles

A few meters from a beach with turquoise waters, it extends over 3 km². Between a landscape of dunes and lush vegetation, it is the place for 4x4 rides, horseback riding, camel rides... but it is not ideal for swimming due to its very high salt content.

Before being an essential tourist site, Lake Retba has been exploited for its salt since the 1970s. Deposited in a thick crust at the bottom of the shallow lake, the salt is broken using large sticks, then placed on canoes . It then dries on the banks of the lake, to be marketed. To break the salt, men spend entire days in very corrosive water: they protect their skin by covering themselves with a thick layer of shea butter.

However, this unique ecosystem is seriously threatened by the overexploitation of sea salt. If in the 15th century, the surface of the lake was 15 km2, it increased to 4 km2 in 1976 and has continued to decrease since.

Did you say pink?

The water of Lake Retba has only been pink for around forty years. Its pink is changeable, can go from candy pink to a fairly deep mauve, and the color palette is not due to a difference in lighting! While the Atlantic Ocean has 30 g of salt per liter, and the Dead Sea 250g/L, Lake Retba accumulates more than 320 g of salt per liter, due to its proximity to the ocean: it retains some salt. In these extreme conditions, certain bacteria still manage to develop: the microscopic algae – cyanobacteria – present in the water produce a red to orange pigment, similar to beta-carotene, to fight against salt. The algae thus protects itself from dehydration.

The development of the pigment depends on the salinity level of the water: air temperature, light, water evaporation will play their role in the color of the water. The drier the air, the brighter the color. The pink is very marked when the dry season wind blows, when the air is hottest, in the middle of the day.

But where has its beautiful color gone?

Yes, but the site has lost all its charm as well as its famous pink coloring. Indeed, a real ecological disaster is happening at Pink Lake, which was until then one of the most visited tourist sites in Senegal. This heavenly site has lost all its pinkish tint due to human intervention because wastewater and rainwater from the suburbs are directly poured into the lake through an evacuation canal, considerably altering its ecosystem. Today, the lake and its surroundings are completely deserted, as are the surrounding hotels. And now its entire ecosystem, faced with rising water levels, is under threat.

According to some scientists, the lake could become permanently pink again if the government and benefactors put in the resources. However, restoring the lake will require very serious studies and research. Some specialists affirm that the excess water, aided by the circumstantial pipes, were the basis of the discoloration of the lake, others on the other hand estimate that the pink lake, within its geographical limits, was one third empty due to the abusive extraction of salt which remains the main cause of its discoloration.

The tourism sector is very affected, because tourists are becoming increasingly rare and the players who revolve around it, such as sellers of art objects and others, are experiencing very difficult times.