Prof. Peter Croot is a marine biogeochemist whose research focuses on understanding the role of biogeochemical and physical processes on the concentration and distribution of trace elements and chemical species in the ocean and their role in controlling primary productivity and ecosystem function. His work combines different strands of ocean observations (in situ and satellite, physical, chemical and biological), with laboratory studies to elucidate the kinetics and mechanisms underpinning the transformation of chemical species in the ocean from the surface to the deep. A key theme of his current work is to combine satellite data with in situ optical measurements, nutrient and trace metal concentrations along with measured cell abundances (via flow cytometry) to examine the influence of picoplankton on biogeochemical cycles in the global ocean. Dr Croot has extensive experience of working in the open ocean, most notably in the oxygen minimum zones of the Atlantic and Pacific and in the iron limited Southern Ocean (Participating in 4 iron enrichment experiments: SOIREE, SOFeX, EisenEx, EIFeX). He is a co-PI in the SFI research centre iCRAG (Irish Centre for Research in Applied Geoscience) and an active collaborator in the marine biogeochemical community through the GEOTRACES, IMBER, GO-SHIP and SOLAS communities. In 2021 he was the convener for Chapter 7N Open ocean, for the United Nations World Ocean Assessment II.