“Why Has the Water Turned Green?” A Problem of Eutrophication in Primary School

This paper analyses how 224 students from the fifth and sixth grade recognise the key aspects, i.e., the causes, consequences, and solutions of the eutrophication problem affecting the relevant ecosystem in their region. Two instruments were used: a report sheet in which students work through the causes and consequences associated with the problem; and a personal letter addressed to the competent authority, which proposes solutions. The results show that students from the sixth grade recognised more complete interconnections between the agricultural development of the area and the changes that occurred in the ecosystem. In the identification of the key phases of the eutrophication process, students from both courses presented similar difficulties. Regarding the solutions, some reluctance was observed to limit agricultural activity. This reveals that students’ social perceptions about the importance of agriculture for their region may be a possible influence on their solutions. Finally, five models were established regarding the understanding that students reach of the problem as a whole. More than half of students were included in the same model, comprising those who were able to adequately identify the causes and whole process of eutrophication, as well as those who defended the advantages of the proposed solution. Educational implications are discussed in this paper.