Gerard is an oceanographer working at ICARUS (Irish Climate Research and Analysis Unit) and a lecturer in the Department of Geography at Maynooth University.

Gerard previously worked at the National Oceanography Centre in Southampton, UK, where he worked with the RAPID team measuring the Atlantic Meridional Overturning Circulation.

He is a leading observational physical oceanographer, with particular interest in changing ocean circulation and sea level rise. He is the 2019 recipient of the IAPSO early career medal for physical oceanography.