Chemical agricultural runoff is destroying the lake's ecosystem
Just over a third of the land in the Lake Atitlán basin is used for agriculture (mainly coffee, vegetables, and fruit). Since the 1950s local farmers have been pressured to abandon natural farming and use chemical fertilizers, pesticides, fungicides, and herbicides instead. These toxic products are highly subsidized and poor farmers are strongly encouraged to use them copiously to boost their production.
Soil fertility and sustainable agriculture depend on a balanced supply of essential nutrients and minerals, and the continuous and excessive use of chemical products destroys this balance. They replenish only nitrogen, phosphorous, and potassium, while killing soil-friendly microorganisms such as insects, fungus, and bacteria.
Over time the soil becomes depleted of trace minerals and essential micronutrients. It hardens and becomes much less fertile. Chemical agriculture also contaminates the food people grow and depletes crops of micronutrients. Ultimately, it will kill the microorganisms that the soil needs to live and nothing will grow any more.
During rainy season thousands of tons of agricultural runoff, containing nitrogen, phosphorus, and trace chemicals, flows down into the lake from the surrounding fields. This contributes significantly to nutrient overloading, causes algal blooms and oxygen depletion, and makes the water hazardous to human health.