Sulaymaniyah – A water lake in a city in the Kurdistan Region of Iraq is surprising because it changes color to several colors, such as purple, white and pink, as temperatures intensify.

The lake has rare species of endangered turtles, in addition to containing large amounts of sulfur and rare algae, and this has prompted some to use them in the treatment of many skin diseases such as allergies.

Its age, depth and width

The lake is called "Qura Ku", and it branches from the Rania River (Little Zab) in the Sulaymaniyah Governorate in northeastern Iraq, and reaches a depth of about 27 meters and a width of about 370 meters.

Archaeologist Mulla Ismail Nur al-Dini estimates that the lake is about 5,<> years old, and it was formed by natural and environmental variables, away from human intervention. It is located within the city's ancient archaeological areas, and is characterized by the emission of an egg-like smell.

Speaking to Al Jazeera Net, Nour al-Dini refers to one of the wonders of this lake through what was discovered by a German team that conducted research on it years ago; German scientists found that the lake has rare species of animals that are close to extinction in the world, such as some species of turtles, as well as very small fish and worms that are not found in other lakes.

The "purple" lake reaches a depth of about 27 meters and a width of about 370 meters (island)

Scientific explanation

Bodies of clean water with sufficient oxygen in the daytime usually look light blue like the color of the sky, due to the electromagnetic absorption of water and the scattering of white light. Dissolved elements or suspended impurities may give a different color to the water, while bacteria and algae give lakes a green color due to their richness in organic matter.

The scientific explanation for the discoloration of this lake is due to purple sulfur bacteria, as well as non-sulfur-based purple bacteria, according to molecular microbiologist Dr. Behrouz Al-Jaf.

Al-Jaf, an assistant professor at the University of Sulaymaniyah, explains that these bacteria can live in water with high sulfur content, so that they can make their own food through photosynthesis with no oxygen, unlike what plants do, where they use sunlight in addition to organic matter as a source of energy with hydrogen sulfide gas with a stinky smell as a reducing agent and not water.

According to Al-Jaff's interview with "Al Jazeera Net", sulfur bacteria live at the bottom of the water and in hot sulfur springs, where they can resist high temperature, so they are active in ponds in the summer, when the amount of heat and light is appropriate.

"These bacteria make the color of the water body purple, and the intensity of the color fluctuates between blue, violet and purple depending on the amount of organic matter, the intensity of bacterial growth, temperature, and even the percentage of salts that encourage other salt-loving bacteria to make color changes, as well as the intensity of light, temperature, and even the angle from which the water is viewed."

Lake discoloration due to purple sulfur bacteria and non-sulfur-based purple bacteria (island)

Vertical view from height

Sardar Abdul Rahman, an expert in the field of environment and geography, says that the color of the lake changes when viewed vertically from a very high and high distance, unlike the horizontal gaze that sees water in its natural color.

Abdul Rahman explains – to Al Jazeera Net – that the lake's proportions of water remain the same and never change during the seasons of the year, describing this as a very "rare" case, unlike many other rivers and lakes whose level decreases due to drought and lack of rain.

He stresses that many people with skin diseases, including allergies, resort to lake water and sand to treat themselves because they believe that high levels of sulfur will help heal.

Lake "Qura Ko" is absent from the tourist map, although it is registered as a tourist area with the tourist department in the province (Al-Jazeera)

Tourist complaint

Regarding the tourism aspect, the Director General of Tourism and Travel in Raperin in Sulaymaniyah Governorate, Aram Beirut Ahmed, complains about the lack of tourism services for the "Qura Ko" (purple) lake, and that this made it absent from the tourist map in the Kurdistan Region of Iraq, despite the fact that it is registered as a tourist area with the tourist department in the province.

In an interview with Al Jazeera Net, Ahmed calls on government agencies in Kurdistan to pay attention to this lake and make it a rare tourist area to attract the largest number of tourists and move the economic wheel better in Sulaymaniyah.