Phyto-remediation is the use of plants to decrease the level of contaminants in soils, sludges, sediments, surface water, and groundwater. It is an ideal cleanup technology for Lake Atitlán: natural, low-cost, and driven by solar energy; it can help to keep the lake alive by mitigating the effects of constantly increasing pollution. There are three simple, inexpensive phyto-remediation solutions that we can implement now to filter pathogens and remove nutrients from the lake. They will help to “buy time” for the longer term solutions that will prevent the inflow of excess nutrients and pathogens.
The Tul plant grows naturally along the shores of Lake Atilán, where it provides a protective barrier against erosion and a filter of contaminants as well as habitat for waterfowl, fish, crustaceans, and migratory birds. Tul is very good at absorbing nutrients that are contaminating the lake, plus each plant has billions of beneficial microbes living on it which consume even more nutrients and also filter the water.
Tul in the lake has decreased significantly though due to a rapid change in water levels a few years ago. Thus, we are spearheading initiatives with local organizations and volunteers to reforest Tul.
Please read about our tul-reforestation projects and Donate to our tul re-forestation campaign.
Here’s a collage of pictures from our recent Tul plantings!
Please enjoy our interactive map. On this map the pins are specific locations that we have planted. Each one contains details about where we planted, who helped us, how much was planted that day and pictures from the events. Red lines are areas not suitable for planting, green are existing Tul forests and blue are areas that need to be planted. Obviously this map is not finished. Eventually we will have the whole Lake mapped out.
Rafts covered with soil and plants are anchored in the lake to create floating garden “wetlands” that clean the water. The plant roots grow through the raft bottom into the lake, where they absorb nitrogen, phosphorous and other nutrients. Beneficial bacteria create a biofilm on the raft and roots that consumes even more nutrients and provides effective bio-filtration for the Lake.
Pollutants such as metals, pathogens and other particulates are also filtered out since suspended solids bond to the biofilm. This makes the water clearer, which lets light penetrate deeper, thereby promoting plant growth deeper and thus bringing oxygen to deeper waters. Organic matter that attaches to the underside of the floating islands also provides food for fish, and the islands provide habitat for birds. Planting floating gardens with commercially valuable plants can increase the impact of this project.
Like big hula hoops, floating rings are placed in the lake, and the interior is filled with water hyacinths, which work to consume contaminants and filter the water. Every couple of weeks, some of the hyacinths are harvested for use in composting operations to improve organic farming in the Lake Atitlán area, thus removing nutrients from the lake and converting those nutrients into high-quality organic compost for local farmers.
The fast-growing water hyacinth can be invasive if it grows out of control in non native environments. If controlled, however, this plant is an excellent resource for phyto-remediation. Water hyacinth can be planted in floating rings (giant hoops) to control their expansion; the roots hang down up to a foot below the surface creating a huge floating filtration area that absorbs excess nutrients from the water quickly. The plants can be harvested frequently and used for organic composting.