Plant Remediation and Repairing a Dying Lake

By: Devon Mendez

From the moment we landed in Guatemala I began to take in the multitude of differences that existed between my home in Ohio and the loud and bustling Guatemala City. As we traveled throughout the country, we were able to see and experience many incredible things, including a visit to Lake Atitlan, a lake created by the three volcanos, one of which you can see in the background of the photo below. While on the surface the lake seemed healthy, a meeting with members of the organization “Friends of Lake Atitlan” taught us that the water was anything but.  

For years the lake has been contaminated with many different types of pollution, including chemicals from hotels and industrial companies, phosphorus and nitrogen run off from farms, as well as sewage. Accumulation of pollution has led to the water in the lake to be extremely contaminated, causing harm to all those who drink it. One of the most significant risks present in the water of Lake Atitlan is phosphorus and nitrogen. This excess phosphorus and nitrogen are largely caused by runoff of both sewage and fertilizer, both known to be high in these nutrients. As a result of these excess nutrients there are often high numbers of cyanobacteria and coliforms, organisms that are known to cause severe negative health effects, including diarrhea. With diarrheal disease being one of the leading causes of death for children under five, it is imperative that these issues be resolved so that children can remain healthy and have access to clean water. 

To decrease the amount of phosphorus and nitrogen available in the water, “Friends of Lake Atitlan” have begun to research the use of plants for the absorption of these chemicals. These plants, predominantly consisting of algae and Eichhornia crassipes, are typically used for tertiary treatment of the water. Eichhornia crassipes is a shrub like water plant with roots that are able to absorb large amounts of phosphorus. This absorption occurs for approximately 21 days before turn roots turn black which denotes the plant is not able to absorb any more contaminants. As for the algae, its role is largely to add oxygen to the water, which helps encourage life within lake, and help combat the hypoxia that is often caused by harmful algal blooms from other species of algae.  

While plant remediation of the water is a newer technique and has not been implemented on a large scale yet, the research being done by “Friends of Lake Atitlan” shows a great amount of promise. It is my hope that, through a bit more research to increase ourunderstanding of how the plants can be utilized, we can begin to revive the lake. The use of the plants would provide a way to begin resolving these issues in a sustainable and natural way, aiding in the recovery of the ecosystem.  

Devon Mendez

CFAES Graduate Practicum Student

Department of Veterinary Preventive Medicine and College of Public Health