Why blood rain soaked Spain

The rain brought more than water last autumn to some villages of Zamora, Spain.

The villagers noticed that the water in their fountains seemed blood-soaked. Researchers finally confirmed that the red rain was due to a strange algae that turned red when stressed. But how did the algae get there, that's still a bit of a puzzle.

Before that people started speculating everything from someone having spilled something into the basin, contaminants dumped from airplanes and even biblical plagues.

Joaquín Pérez, who lived nearby collected the 'bloody' rainwater to see if he could find the culprit, according to a statement by the Spanish Foundation for Science and Technology.

He gathered samples and found there were particles in the water staining it red and send the samples to researchers at the University of Salamanca.

Turns out that microscopic freshwater algae called Haematococcus pluvialis produce red pigment when they're stressed, which gave the water it's red tint.

This species of algae are found in water bodies in the Northern Hemisphere.

How the micro-algae reached the peri-Mediterranean environments is still not clear.

Analysis of weather data suggests that the algae could have hitchhiked to western Spain on the winds, but right now the source of this bloodbath are still unknown.  

This isn't the first time it's rained blood. In 2001, Kerala was washed down with blood rain and even Sri Lanka because of the algae Trentepohlia.

The results have just been published in the Spanish Royal Society of Natural History Journal.

Read more here.