The Don River watershed is located within Canada’s most highly urbanized area—metropolitan Toronto. To help assess the ecological health of the Don, biology students investigated the main Don River tributaries using macroinvertebrates instead of chemical indicators. As concerned investigators, students brought awareness to the community and especially to the nonbiology students who volunteered with the study. All students helped collect data, and some volunteered to pursue library research. The students' final task was to present their findings at a local science center.