The fourth edition of this bestselling text has been rigorously updated to reflect major new discoveries and concepts since the previous edition in 2019. Many sections have been extensively revised with the help of co-authors with expertise in specific fields. This new edition reflects important new findings in Marine Microbiology revealed by further development of high-throughput sequencing, omics and single-cell technologies which have led to major advances in understanding of how the activities, interactions, and functions of marine microbes affect ecosystem processes and global biogeochemical cycles.

Novel pedagogy is designed to aid students’ interest and understanding and encourage exploration of current high-profile research topics, including the physiology of planktonic microbes and their role in ocean processes; the impacts of rising CO2 levels and climate change on microbial community structure and ocean processes; the evolution of viruses, organelles, and eukaryotic life; interactions of microbes with plastic pollution; and emerging diseases of marine life and their control.

This is the only textbook addressing such a broad range of topics in the specific area of Marine Microbiology, now a core topic within broader Marine Science degrees.

Dr Colin Munn is Honorary Fellow at the Marine Institute, University of Plymouth. He has a PhD in Microbiology from the University of Birmingham (1971-1974) and was Associate Professor in Microbiology before he retired in 2017. While at Plymouth, Colin was Admissions Tutor for Marine Biology Undergraduate Programmes, Principal Lecturer in Microbiology, and Head of Department of Biological Sciences. He is passionate about teaching the importance of microbes and enabling students to understand the remarkable new discoveries that are revolutionising our understanding of the field, especially in the marine environment. Colin has particular research interests in the interactions between symbiotic and pathogenic microbes and their hosts. He has studied microbial interactions with plants, invertebrate animals, fish, and humans and is a strong advocate of a comparative approach. His recent research has taken him into various aspects of marine microbiology, including microbes in coral health and disease and the effects of environmental stress on microbial community structure in corals and other marine invertebrates. Colin was a Visiting Professor at James Cook University/Australian Institute of Marine Science (2002), St George's University, Grenada (1998-2002), Central University of Venezuela (1985) and University of Victoria, Canada (1981). He is now a member of the review panel for DEFRA, US SeaGrant, US National Science Foundation, Netherlands Polar Foundation, US-Israel Binational Science Foundation. Colin is a referee for Proceedings of the National Academy of Sciences USA, ISME Journal of Microbial Ecology, Applied & Environmental Microbiology, Journal of the Marine Biological Association UK, Freshwater Biology, Archives of Microbiology, Microbial Ecology, Marine Pollution Bulletin, FEMS Microbiology Ecology.

Dr Taylor Priest received his BSc in Marine Biology and Oceanography at Plymouth University and an MSc in Marine Microbiology at the Max Planck Institute in Bremen. He went on to gain a PhD in the Molecular Ecology department at the same institute, his research centring around ecologically characterising microbial life that exists at the interface between the Arctic and Atlantic Oceans. More recently, Taylor moved to the Microbiome Research Lab at ETH Zurich as a Postdoctoral Researcher where his research is focused on understanding how the extant diversity of microorganisms we see across Earth’s biomes have adapted and evolved over time.

Dr Cordelia Roberts is a Postdoctoral Research Assistant in Marine Microbial Ecology and Biogeochemistry, and previously completed an MRes and PhD at the Marine Biological Association (MBA). As a researcher, Cordelia is interested in looking at dead, dying and faecal material in the ocean (similar to leaf litter on land) which form sinking and suspended particles. These particles are a habitat and food source for microscopic organisms, and the interactions that take between microbes and their home/food play a crucial role in cycling carbon in the ocean. Cordelia also provides support to Masters and PhD students working with microbiome data including sponge and diatom (microalgae) associated bacteria and sediment-dwelling fungi.

Professor Justin Seymour is the leader of the Ocean Microbiology Group in the Climate Change Cluster (C3) at University of Technology Sydney. The over-arching goal of his research is to understand how the seas smallest inhabitants ultimately control the ecology and biogeochemistry of the Ocean. His research interests incorporate aquatic microbial ecology and biological oceanography, and his research team tackles the important questions of who are the key microbial populations in different ocean ecosystems, and what they are doing?

Dr Joanna Warwick-Dugdale is a Postdoctoral Research Assistant at the Marine Biological Association (MBA) in Plymouth. She is fascinated by how communities of the smallest marine organisms (i.e. prokaryotes; algae; viruses) function to drive systems at the largest scales (e.g. global nutrient cycling). Previously Joanna has focused on the characterization of Open Ocean and Coastal viral communities, key players of global biogeochemistry who remain largely underexplored. To accomplish this, she developed a hybrid, long- and short-read viral metagenomic method during her PhD, a NERC DTP at the University of Exeter (UoE) and Plymouth Marine Laboratory (PML). During her first post-doctoral position at the UoE, Joanna further developed this method to include viral communities that are ‘active’ in host cells and applied it to the investigation of a hypoxic marine environment, work that is highly relevant to the reduction in oxygen levels of ever-growing areas of the Global Ocean. Currently she is conducting Horizon Europe funded research investigating temporal and spatial patterns in marine biodiversity of the Western Channel Observatory and other European time series.

Dr Erik Zettler is a microbial ecologist who was a member of the scientific community in Woods Hole, USA from 1985 till 2017 when he joined the Royal Netherlands Institute for Sea Research (NIOZ). From 1985-1994 he was a member of the Biology Department at Woods Hole Oceanographic Institution where he worked primarily on open ocean picoplankton using flow cytometry. From 1994-2016 he taught and did research at SEA Education Association, as Science Coordinator, Professor, and Associate Dean. It was during research cruises with undergraduate students on the SEA sailing research vessels that he first became interested in plastic marine debris, and particularly the role of microbial biofilms on the fate of plastic in aquatic systems. Erik has participated on over 60 research cruises collecting oceanographic data including plastic marine debris in the Pacific, Atlantic, Caribbean, and Mediterranean. His research for the last 20 years has been facilitated by students and citizen scientists, and whenever possible, he escapes from his computer to work and teach in the field. Most recently he has taught summer courses in oceanography at Shoals Marine Laboratory in Maine, USA, and island ecology at University of the Azores, on the island of São Miguel