The document describes a river project conducted by three students - Mara Neira Conde, María Méndez Lorenzo, and Cédric Diego Daumas. At their station, they examined the biological quality of the river by identifying macroinvertebrates and discussing biodiversity with elementary school children. They introduced materials like nets and magnifying glasses. The students explained invasive and native species, showed macroinvertebrates up close, and let the children find organisms in the river. They felt the activity went well and that the children participated actively and learned about macroinvertebrates.