Throughout 2025, the Rivers and Forests Alliance (RAFA) partnered with Rios Lodge on an ongoing environmental education initiative designed to improve water quality in the Pacuare River.
As part of this program, individual travelers and visiting groups staying at the lodge on the banks of the Pacuare River learn about river ecosystems while engaging in a hands-on activity with tangible environmental impact: creating mud balls infused with beneficial microorganisms.
How the Mud Ball Activity Works
Guests help make mud balls using EM Research Organization Inc. technology that blends clay, molasses, rice bran, and Effective Microorganisms (EM). Once formed, the mud balls are stored in crates in a dark storeroom at the lodge, where they dry and ferment for about three weeks.
After this fermentation period, the mud balls are ready for their next stage. New lodge guests then toss them into the river, completing the cycle and helping clean and oxygenate the Pacuare.
The Science Behind Effective Microorganisms
The EM technology used in this program was developed in Japan by Dr. Teruo Higa. In Costa Rica, the application of this technology is guided by Takatsuru Nishikawa, representative of Tecnología EM Costa Rica, which supports environmental projects across the country.
The approach uses beneficial microbes, such as lactic acid bacteria, yeast, and photosynthetic bacteria, to outcompete harmful bacteria in polluted environments. Once submerged in the river, the microorganisms in the mud balls activate and begin breaking down organic sludge on the riverbed. Over time, this process helps restore a healthier microbial balance, improves oxygenation, and contributes to better overall water quality.
Guardians of the Pacuare Program
RAFA developed this environmental education activity as part of its Guardians of the Pacuare Program to engage volunteers in hands-on conservation while deepening their understanding of freshwater ecosystems and river restoration.
Photos shown here capture the energy and enthusiasm of middle school students and teachers from the Jaco Learning Center, who participated in the mud ball activity in June 2025.
RAFA extends its sincere thanks to our Guardians of the Pacuare partner, Rios Lodge, for their continued commitment to connecting tourism and conservation. Through this ongoing collaboration, visitors leave not only with unforgettable memories of the Pacuare River, but also with the knowledge that they helped protect it.
