This article reports one of the case studies in a 3-year longitudinal study in environmental science education. This case explores the process of teaching about ecosystems through co-teaching and co-generative dialogue in a Year-9 science classroom in Western Australia. Combining with co-teaching and co-generative dialogue aimed at transforming classroom practices and stimulating students' awareness of ecosystems and bio-diversity. The research employed mixed-methods methodology with multiple research methods. The results show that the teachers and the students were engaged and enjoyed the activities. The fieldwork experiences stimulated student critical voice, group cohesiveness, and student involvement.