I have combined two threads throughout my career: marine ecosystem functioning and calanoid copepod taxonomy and phylogeny. I became interested in the identification and taxonomy of planktonic copepods because these Crustacea are numerically dominant among marine zooplankton and feed near the base of the marine food web. I aimed to document the species present in Southwest Pacific waters. Of necessity, I had to take a global view. We now known that the New Zealand planktonic copepod fauna is composed of species that are circumglobal in subantarctic waters, cosmopolitan subtropical or Pacific Ocean subtropical and includes a few indigenous species. A few species live in brackish and freshwaters. Among this fauna are species that live just above the sea floor including a primitive genus of significance to an understanding of the evolution of planktonic Copepoda. Its discovery enabled a proposal to reorganise the classification of the most primitive calanoid copepod families. I also worked with overseas colleagues on the identity of a common planktonic copepod genus Calanoides that lives in coastal upwelling systems from the Arabian Sea, around southern Africa to the Bay of Biscay. My identification expertise has been applied to an analysis of the food of fish larvae, preparation of electronic interactive identification keys as a service to ecologists, and the role of zooplankton in New Zealand’s marine ecosystems.