I began my career with a focus on the ecology of limpets, which are more diverse and do more extraordinary things than anywhere else in the world. That passion developed into a broader exploration of rocky-shore ecology, competition, predation and other forms of interactions, and I shifted from an observational approach to experimental field work. The impact of alien species such as the blue mussel Mytilus galloprovincialis and the crab Carcinus maenas formed part of the focus of my postgraduate students. My interests then extended to include estuarine ecology, and particularly the remarkable role that sandprawns and mudprawns play. Sandprawns are known as 'bioturbators' because they turn over prodigious quantities of sediment, and powerfully influence the rest of the community, from bacteria to diatoms and other invertebrates. I have enjoyed a profitable and companionable collaboration with Deena Pillay on these amazing animals, including a monographic review of their ecology. From this ecological grounding, I became involved with research on marine invertebrates and algae that are of commercial importance, or are harvested as a source of food by recreational and subsistence fishers, including rock lobsters, abalone, urchins, mussels and seaweeds. This led to involvement with the development of a new fisheries policy and the development of Marine Protected Areas.