Near the end of October and beginning of November, a large population of Cyanobacteria was detected in Lake Atitlan in Solola, Guatemala.

This situation affects 200 thousand inhabitants of towns surrounding the lake.  According to previous studies, the presence of cyanobacteria had been detected approximately 30 years ago in very scarce amounts.

SERVIR, in its mission to provide timely and accurate environmental information, has carried out preliminary analyses of the affected area and, based on satellite images including from Landsat, EO-1 (ALI & Hyperion), and ASTER, is monitoring the behavior of this cyanobacteria in the lake.  See maps below.

TEMPORAL MONITORING

According to this time-series analysis, the first remote detection of the cyanobacteria  was on October 30, 2009, covering approximately 5% of the lake.  Later, the cyanobacteria proliferated, reaching its maximum coverage of 38% of the entire lake on November 22, 2009.   The last image acquired was captured on December 1,  2009, and shows a decline in the cyanobacteria population, covering 27% of the lake, corresponding to a decrease in 11% from November 22.

  Area affected by cyanobacteria

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Image credits: SERVIR/CATHALAC/NASA/USAID/GEO

Cyanobacteria

Photosynthetic bacteria with properties  common to algae, mainly concerning chlorophyll and oxygen generation.  Both carry out the processes of photosynthesis during the day and nitrogen fixation at night.

Some species of cyanobacteria (Lyngbya hieronymusii in Lake Atitlan) produce toxins and can poison humans who live in the same environment and make use of the contaminated water.  This occurs mainly during blooms (excessive proliferation), especially in fresh or brackish water with favorable temperature conditions and abundant nutrients such as phosphorus.

References:

Ochaeta, Francel V. 2009. Boletín informativo No. 01

http://es.wikipedia.org/wiki/Cyanobacteria

http://www.aetox.es/revista/revtox.18.2/revtox.18.2.cianobacterias.pdf