It is a "chocolaty" pigmentation of the water, in what used to be called the "Enchanted Lagoon."
This has attracted the attention of biologists and environmentalists because of the unusual color of the lagoon, and also the people and tourists who visit the area. This lagoon has been the site of important events of the fly boarding sport (which takes place in the water and the person is propelled by water hoses up to 20 meters above the surface,) and it has been visited by Canadians who are used to performing this sport in Canada. It was also the ideal place for the launching of flyboarding in Mexico because of its depth and large size, almost 2.5 kilometers long and 1.2 kilometers wide located inside a volcanic crater. Very close to the lagoon there are hot springs wells confirming the volcanic activity in the vicinity.
The Santa Maria del Oro Lagoon is very well known for its natural blue and green colors of different tonalities as the water contains volcanic salts and minerals that make it a unique place in the world. But now its chocolate color has captured the attention of worried biologists because it is definitely unusual for the lagoon.
According to biologists, being surrounded by forested mountains and with a single river that runs to the southeast, that may be what has caused this change that presents itself for the first time and is completely abnormal. But the causes that originated this change of color in the water are not yet known, they will have to carry out tests and discard suppositions to be able to clarify this rare event.