His research, teaching and public service is motivated by contemporary environmental issues and centered on the role of transport in ocean, bay, nearshore and estuarine waters. His work has addressed transport of plankton, larvae, contaminants, pathogens, heat, salt, nutrients, dissolved oxygen, and sediment – and he places this work in the context of issues as diverse as marine reserves, fisheries, mariculture, beach pollution, wastewater discharge, wildlife health, desalination, river plumes, coastal power plants, kelp forests, wetlands, marine mining, coastal zone management and impacts of coastal development. At UCD he heads the Coastal Oceanography Group.