MicroTERRA, a Mexican-based startup, is developing a system that uses microalgae to turn fishpond wastewater into protein for fish feed. The circular system not only cleans and oxygenates dirty pond water for re-use but could allow a fish farmer to produce up to 60% of their own feed, the Advocate reports.

The company uses advanced biotechnology and IoT to convert the excess nutrients into high-quality protein. The wastewater flows into bioreactors, where it mixes with microalgae which absorb carbon dioxide from the water, along with nitrogen and phosphorous, converting the nutrients into protein, and releasing oxygen. The cleaned water is returned to the fish pond, while the protein is mixed with other ingredients to create pellets for fish feed. Technicians can monitor the system remotely with sensors and communicate with the farmer if something needs attention, like adjusting the pH, or opening a valve to circulate water.

The company estimates that a 100,000-liter system would cost about $250,000. MicroTERRA is focusing on fish farmers in Latin America as the targeted market and fish feed producers as a potential market of sustainable protein.

The company was selected for the 2019 cohort by the Techstars Sustainability Accelerator, a prestigious three-month mentoring and business development program backed by The Nature Conservancy. The program seeks to support viable businesses that are addressing top environmental challenges, including protecting land and water, providing food and water sustainably, building healthy cities, and tackling climate change.