[2][3][4][5][6] Branfireun's research focused on understanding the bidirectional nature of hydrological-ecological interactions at a range of spatial and temporal scales.

[1][2][4] Branfireun has been involved in projects studying the hydrology, ecology and biogeochemistry of wetland-dominated environments from the Canadian subarctic to the subtropics of Mexico.

[1][2][4] Branfireun and colleagues have been conducting field research with the Grassy Narrows First Nation to learn more about how mercury moves through the environment, ultimately ending up in fish which can result in Minamata disease in humans.

As a result, members of the Grassy Narrows First Nation suffering long-term effects from mercury poisoning are now eligible for Ontario Disability Support Program.

[15] Since 2010 he has been a professor in the Department of Biology and Centre for Environment & Sustainability (joint appointment) with a graduate cross-appointment in Earth Science and Geography at Western University.