In Australia, there is a crisis in science education with students becoming disengaged with canonical science in the middle years of schooling. One recent initiative that aims to improve student interest and motivation without diminishing conceptual understanding is the context-based approach. Contextual units that connect the canonical science with the students' real world of their local community have been used in the senior years but are new in the middle years. This ethnographic study explored the learning transactions that occurred in one Year 9 science class studying a context-based Environmental Science unit for eleven weeks. Outcomes of the study and implications are discussed in this paper. (Contains 2 tables and 1 figure.)