Integrating marine fungi into the structure and function of pelagic ecosystems

Even though marine fungi have been known to exist since the 19th century, the application of molecular ecology tools has established a foundational understanding of the widespread distribution and diversity of the ocean mycobiome. Recent evidence has indicated the functional roles fulfilled by planktonic fungi (mycoplankton) in open water ecosystems. Some marine mycoplankton are apparent saprotrophs that utilise high-molecular weight substrates via extracellular enzymes, whilst others are potential parasites of phytoplankton, particularly diatoms. A novel and open research question is to understand how marine mycoplankton fit within the wider structure and function of pelagic marine ecosystems. This research is timely because of the development of approaches to study marine fungi in the laboratory and in situ. Saprotrophy is an already well-established functional role of marine bacterioplankton and it is currently unknown how fungal and bacterial saprotrophy are interrelated. Even though fungal parasitism of marine phytoplankton is known, the prevalence and importance of phytoplankton parasitism and change through time and space remain largely speculated. This aim of this PhD project is to address these knowledge gaps through an integrated and complementary programme of laboratory, field and modelling based approaches