Fungi in the food web: the role of marine fungi in the trophic ecology of pelagic ecosystems

Project Rationale
Fungi are widespread in the marine environment from coastal waters and shelf seas to the open ocean and polar regions (Amend et al 2019). The ecological roles of planktonic marine fungi (mycoplankton) are varied, including parasites of other plankton and saprotrophs that degrade particulate organic matter (Grossart et al 2019). Molecular studies of the gut contents of some zooplankton, particularly copepods, have shown a high abundance of fungi, suggesting that fungi are a prey resource. Copepods are amongst the most abundant multicellular organisms in the marine environment and have critical roles in ecosystem functioning, including maintaining important trophic links in the marine food web and impacting the biological carbon pump (Giering et al 2014).
A novel and open research question is to understand the prevalence, importance and function of fungi in the marine copepod diet in terms of their biology and ecology. The aim of this PhD project is to address these knowledge gaps through an integrated complementary programme of laboratory and field-based research approaches. Copepods will be studied in detail in the laboratory through feeding experiments with and without fungi. Copepod populations will also be studied in the marine environment across a range of habitats from coastal waters to the open ocean.

Methodology
A range of approaches will be utilised to address the knowledge gaps outlined above. Copepods will be collected from the marine environment and studied for gut content analysis using molecular tools. Study sites will include locally from Plymouth Sound and the Western English Channel, and during open ocean research cruises, such as at the Porcupine Abyssal Plain Sustained Observatory. Additional copepod samples will be provided from the Continuous Plankton Recorder (CPR). Copepods will also be studied in the laboratory under highly controlled experimental conditions. The Cunliffe group at the MBA has established a marine fungi culture collection, which will provide strains for experimental analysis. Feeding experiments will be performed to determine the specific impacts of fungi on copepod biology and ecology, including biochemical composition, behavior and ecological fitness.

Training
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and based at the Marine Biological Association in Plymouth. Specific training will include marine mycology (e.g. cultivation, microscopy), zooplankton biology and ecology (e.g. behavioral experiments), trophic ecology (e.g. biochemical/lipid analysis) and ecological timeseries analysis using molecular ecology techniques.