Meet Nathan Montelongo, seventh-grader who used shellfish waste to clean water

A La Joya, Texas seventh-grader named Nathan Montelongo began investigating the potential of discarded shellfish shells to remove pollution from water. The idea came to him after a local fisherman warned him of microplastic contamination in recently caught fish during a fishing trip along the Rio Grande. Nathan found shellfish shells to be a promising material, as they contain chitin, which can be processed into chitosan, a biodegradable substance capable of binding with pollutants.

Nathan collected discarded shellfish shells from local restaurants, turning them into chitosan powder for his experiments. His first test involved using glitter to mimic small particles, with the chitosan powder successfully capturing between 55% and 75% of the glitter. Nathan then proceeded to test the chitosan on actual water samples contaminated with visible plastic, observing that the water became clearer as the chitosan coagulated.

He further tested the material's effectiveness on Rio Grande water, using Arduino sensors to measure improvements in water quality. Additionally, Nathan explored the impact of chitosan-treated water on zebrafish embryos, finding that the embryos exposed to chitosan-treated water showed better development than those in untreated water.

Finally, Nathan designed a raft capable of monitoring water quality and releasing chitosan accordingly, creating a prototype for an automated cleanup system. Nathan's project, which combines recycling shellfish waste, testing a biodegradable material, monitoring water quality, and exploring an automated approach to pollution cleanup, has earned him a spot among the 30 finalists in the 2026 Thermo Fisher Scientific Junior Innovators Challenge.