From blue and green, Iranian UNESCO site Lake Urmia has now turned into a lake of crime scene with its blood red color. Now, scientists have found an explanation to this perplexing phenomenon.

Culprits to the Red Blood Lake

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite was able to capture the shocking transformation of the lake. What is even more alarming is that the red blood color transition has occurred in a matter of months only.

Scientists claim that two main groups of organisms are responsible for the red-blood color: a family of algae called Dunaliella and an archaic family of bacteria known as Halobacteriaceae.

"Previous research suggests that Dunaliella salina is responsible for reddening of Lake Urmia," explained Mohammad Tourian, a scientist at the University of Stuttgart in a press release published by NASA.

"In the marine environment, Dunaliella salina appears green; however, in conditions of high salinity and light intensity, the microalgae turn red due to the production of protective carotenoids in the cells."

Shrinking Lake, Saltier Water

Because of the ever-changing and worsening climactic condition, scientists have witnessed the shrinking of the Lake Urmia over the years. According to Mirror UK, Iran's Lake Urmia was once five times the size of Hong Kong, but it has shrunk ever since. A study conducted in 2014 shows the size of the lake has been reduced by almost 90 percent.

Experts explain that as the size of the lake recedes, its water gets saltier, which makes way for the growth of the microscopic algae.

With drought conditions getting more severe, NASA notes that there's a possibility that Lake Urmia's red color could be permanent.

Other Algae Attacks

Microalgae stains have been plaguing the Floridian lakes and beaches as well. Over the summer, cyanobacterium has caused the bodies of water to turn green and slimy. As a result, organisms in the water had perished and people who had touched the toxic waters had gotten skin diseases.

Another reason behind the death of the lake is the intensive water diversion for agriculture, which limits the amount of fresh water reaching the lake. Hossein Akhani, a biologist at the University of Tehran, told Scientific American that Iran's agriculture demands puts pressure on the lake and that it should be taken as an emergency situation to prevent the lake from shrinking further.