Lake Coatepeque turns turquoise

One of El Salvador's natural treasures, Lake Coatepeque, has turned a bright turquoise color.   The unusual coloring is from an algae bloom in the lake.  From the Costa Rica Star:
The authorities of El Salvador declared an emergency in the area of Lake Coatepeque, in the northwest of the country due to an algae bloom that has changed the color of its waters. 
The decision was adopted by the National Red Tide Commission, made of the Ministries of Environment, Health and Agriculture, because of the unusual phenomenon, which gives the water an intense turquoise color. 
As a preventive measure, the committee issued a ban on the extraction and consumption of fishery products from the lake, in Santa Ana department. 
According to preliminary investigations, the change is the result of the proliferation of micro algae species Microcystis aeruginosa, Oscillatoria limosa and Ceratium furca.  The degree of their toxicity is not yet determined, so the government has declared an emergency as a precautionary measure, officials from the ministries explained in a press conference.
The ban on use of the waters of the lake, comes as an economic blow to the fishermen and small comedors located along the shores.   The lake is formed in the crater of an old volcano.

You can read a story of a recent visit to Lake Coatepeque at Linda's El Salvador blog.