Pink Waters of Lac Rose in Senegal Make a Comeback After Nearly Three Years
Heavy rainfall and flooding in Dakar and its surrounding areas in 2022 caused Lac Rose to lose its characteristic pink color.
LAC ROSE, Senegal
The famous pink waters of Lac Rose in Senegal have returned after nearly three years of appearing green due to substantial rainfall and flooding.
Located 35 kilometers (21.7 miles) from Dakar, the lake is known as “Retba” in the local Wolof language and is recognized as one of the saltiest lakes in the world.
The lake’s unique pink hue is due to the presence of *Dunaliella salina* algae, which is also essential for Senegal’s tourism and economy.
For many years, Lac Rose has been a significant endpoint for the Paris-Dakar Rally and is often one of the first natural landmarks associated with Senegal.
Moreover, the lake is famous for its salt production, a crucial economic asset for the country, with around 60,000 tons of salt harvested each year, supporting the livelihoods of approximately 3,000 people.
Salt harvesting takes place from November to June during the dry season in a lake that reaches a maximum depth of 3 meters (10 feet).
Seasonal workers, mainly from Niger, Mali, and Burkina Faso, manually collect the salt.
Source of Pink Color is Green Algae
The pink color of the lake is a result of the growth of the halophilic green algae known as *Dunaliella salina*.
These microscopic organisms produce a red pigment as a protective mechanism against their saline surroundings, which gives the lake its pink appearance.
When the salinity of the lake, which contains about 400 grams of salt per liter, decreases, the algae lose their ability to generate pigment, resulting in the lake’s green color.
Lac Rose, which is currently a candidate for UNESCO World Heritage status, has been working to regain its pink color since 2022.
Greened Due to Heavy Rainfall
In 2022, excessive rainfall in Dakar and nearby areas led to extended flooding.
As a last resort, floodwaters were discharged directly into Lac Rose, causing the water level to rise from 3 meters to 6 meters.
This increase in water levels diluted the lake’s salt concentration, impeding the algae’s pigment production.
The lake’s transformation not only altered its visual appeal but also negatively impacted tourism and salt mining activities in the region.
To restore the lake’s pink color, excess water was redirected into a nearby basin, returning the water level to its original state.
