Professor Peter Gell is a palaeoecologist who examines change in the condition of wetlands over culturally relevant timelines. He has a particular interest in contributing to a better understanding of natural ecological character under the Ramsar Convention. He specialises in the use of diatoms as indicators of present, and past, river and lake condition, particularly in coastal systems and across Australia's Murray Darling Basin. An emerging interest is the use of palaeoecological approaches to reveal past instances of regimes shifts and tipping points in wetland ecosystems. To this end he leads an international working group, Aquatic transitions, that examines the timing and nature of changes in the world's wetland ecosystems. He has also published research on both the Indigenous, and post-European fire regimes of our forest estate and climate variability and change over millennial timescales. He also continues his interests in the use of birds as indicators of ecosystem health.