Pollution - Cyanobacteria Lyngbya
In Lake Atitlan Guatemala
Lake Atitlan in Guatemala is currently experiencing a bloom of blue green algae known as Cyanobacteria Lyngbya caused by pollution from human and organic sources. In 2009 the genus Lyngbya Hironymusii was detected. This year, 2010, the strains Lyngbya robust and Microcystis cf. botrys were detected. The bloom this year is not as severe as last year, and November winds are helping to dissipate it.
Located in the highlands of Guatemala, Lake Atitlan is a scenic wonder and a popular tourist destination in the country of Guatemala. There is a large indigenous population around the lake including Tz'utujil and Kakquichel Maya. Many are subsistence farmers who depend on the lake for all of their drinking water and irrigation. Many others rely on the tourist industry.
Roads To Lake Atitlan are Open
There have been reports that the road into Lake Atitlan is closed. This is only true for the main road in from Solola to Panajachel. That road is closed until January for some needed work. There is an alternate route into Panajachel from Antigua, which is well known by the shuttle drivers. As always, it's safest to travel in daylight only due to changeable conditions.
Regular shuttles are also running from Antigua into San Pedro La Laguna on the othe side of Lake Atitlan. The road into San Pedro is open, but a bit rough in places. The shuttle drivers know it well. If you are driving yourself, then use extreme caution as the road is steep and full of switchbacks.
The lake received a record amount of rain this year which has resulted in many landslides and introduced a large quantity of pollution and new nutrients for the Cyanobacteria to feed on. The level of Lake Atitlan has risen over 3 meters, causing flooding of homes and businesses along the lake shore. The loss in tourist revenue associated with these problems has been very difficult for the many people who depend on it for survival.
Cyanobacteria is a form of blue-green algae naturally occurring in waterways and oceans worldwide. It feeds on pollution from agricultural runoff and human waste. It receives nutrients from the pollution in the form of nitrogen and phosphates in the water. The genus Lyngbya, in Atitlan, contains green pigment chlorophyll which traps the energy of sunlight and enables it to carry on photosynthesis. Most cyanobacteria in small concentrations is generally harmless. When cyanobacteria concentrations increase they can form HAB's or hazardous algal blooms. The toxins produced from a "HAB" can include cyanotoxins that induce everything from mild skin rashes to death of animals in cases of extreme exposure. The toxins from Lyngbya can vary widely over short times and could potentially be highly toxic to dogs who come in contact with the lake.
Another recent development is the appearance of Water Hyacinth in some of the bays of Lake Atitlan. This aquatic plant is highly invasive and can choke waterways quickly.
As of July of this year Health Minister Ludwig Ovalle, and the Deputy Minister of Environment for Guatemala, Enma Diaz held a press conference to report evidence of toxicity of cyanobacteria in humans and asked people around Lake Atitlan to refrain from using the lake water for human consumption, irrigation of crops and to not eat the fish, to avoid possible liver complications. "There is evidence that a low percentage of cyanobacteria has produced a toxin that causes liver damage, diarrhea, skin problems and hepatic encephalopathy, among other diseases," explained Ovalle. There were many cases of severe dermatitis reported around the lake from people who came in direct contact with the cyanobacteria during attempts to "clean" the lake in 2009. This was during the peak bloom, where it had amassed in large quantities.
Both Margaret Dix, a scientist at the Universidad del Valle de Guatemala, and Eliska Rejmankova, a scientist at University of California Davis, agree that the cyanobacteria Lyngbya will return annually for the foreseeable future due to the nutrient load in Lake Atitlan. The current cyanobacterial bloom season starts in early September and lasts through late November. Last year the bloom peaked and covered a large portion of the lake in mid October. Seasonal winds helped break up and dissipate much of the bloom in November.
First International Symposium on Cyanobacteria and Cyanotoxins
September 27-29, 2010 in Guatemala
This symposium held at the end of September has not released any detailed recommendations so far. The Minister of the Environment did release a declaration at the end of the symposium which is reprinted below. One of the clear challenges in monitoring cyanobacteria and cyanotoxins is the lack of laboratories capable of analyzing cyanotoxins rapidly enough to disseminate health warnings to the general public, as is demonstrated by the first declaration of the Symposium on Cyanobacteria and Cyanotoxins.
The symposium was the collaboration of the Agency for International Development USAID United States, the Pan American Health Organization, the Mexican Institute of Water Technology (IMTA), the United Nations Educational, Scientific and Cultural Organization (UNESCO), among others.
(more) http://www.lakeatitlanhealth.com/
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