Zürcher Nachrichten - Back in the pink: Senegal salt lake gets its colour back

No sooner had the news hit social media when Julie Barrilliot, 20, bought a plane ticket to fly over from France.

Widely known as the "Pink Lake," Retba is a magnet for tourists, lying 40 kilometres (25 miles) northeast of the capital Dakar.

Separated from the Atlantic by a narrow dune, the shallow lake is so densely laden with salt that, as in the Dead Sea, bathers float like corks.

Harvesting and selling the salt -- that plays a key role in imbuing the lake with its signature tinge -- from its waters is a lucrative sideline.

But in late 2022, unusual and heavy flooding hit the region, likely aggravated by climate change scientists told AFP at the time, and disturbed the ecological balance of the lake.

Afterwards, the water lost its pinkish colour, proving a hammer blow to salt producers, traders, hotel owners and other commercial activities linked to the legendary "Pink Lake".

"In 2023, we noticed that our activities were slowing down and we undertook to rent a pump to extract the excess water from the lake, which had engulfed the entire ecosystem favourable to its pink hue," Amadou Bocoum Diouf, manager of the Chez Salim hotel, told AFP.

"Its depth had gone from two to six metres (6.6 to 20 feet)," Diouf, who is also president of the union grouping traders and hoteliers of the lake, added.

The pumping operation cost them several million CFA francs (several thousand euros) before the government stepped in, he said.

"But it's not all pink?" remarked Barrilliot disappointedly, who tried to console herself with a horse ride near where she was staying.

The hotel manager Ibrahima Mbaye, who heads an association to protect the lake, tried to reassure her that within an hour or two the pink colour would be back.

"For there to be pink, it needs warm sun and a fresh wind," Mbaye said. His Gite du Lac hotel has been swamped with phone calls from operators and foreign tourists wanting to know for sure that the lake is back to its famous colour.

And just before midday, the waters' shimmer turned to pink.

- 'Capricious' -

Mbaye said that when the conditions are right, there is a high concentration of salt in the lake coming from sea water.

"In contact with the sun, this salt concentration produces a large amount of evaporation, conducive to the proliferation of micro-organisms, particularly those called Pink algae," he added.

Cheikh Mbow, from the state-run National Ecological Monitoring Committee, told AFP that cyanobacteria produced the pink when its red pigment diluted in the water.

When a bus load of tourists pulled up on the pinkest side of the lake, Mbaye's eyes lit up -- his pride at seeing the stretch of water where he was born and that was once the finish line of the legendary Dakar Rally was obvious.

Mouadou Ndiaye, who sells bags and sachets of salt, ran over to the French visitors hoping for some sales before they departed.

"We've hardly had any tourists for more than two years," the 60-year-old said, slightly out of breath and barefoot on the sandy, shell-strewn ground.

He stuck it out during the less-than-rosier times, while many others threw in the towel.

"Many left for the towns and surrounding villages," Maguette Ndiour, head of the Pink Lake salt producers' group, said.

Residents fear intensive building will lead to the lake becoming polluted -- a small group of protesters held a rally that day against plans for 1,000 dwellings near the lake.

Mbow, of the ecological monitoring committee, warned that even minimal pollution could tip the balance.

"It's essential to reduce the negative impact of human activities," he said.

As the sun started to go down by late afternoon, the pink of the lake had begun to fade. "Sometimes it's capricious but it's always beautiful," Ibrahima said, smiling.

T.L.Marti--NZN