MS Thesis Defense: Malcolm Barnard

UNC-CH’s Department of Marine Sciences and the Institute for Marine Sciences is proud to announce the Master’s Thesis Defense of Malcolm Barnard. This event is scheduled for Friday, April 23rd, at 1:00 pm. This seminar is remote only and will be broadcast live online via Zoom (Meeting ID: 932-1650-5788).

Presenter Affiliation: Graduate Student, Paerl Lab Member, Institute of Marine Sciences, the University of North Carolina at Chapel Hill

Title: Adapting oceanic grazing techniques for use in high productivity systems

Abstract: Grazing of phytoplankton by heterotrophic bacteria and zooplankton plays a crucial in carbon and nutrient cycling dynamics along the freshwater-marine continuum. While oceanic grazing rates are well studied, grazing rates in freshwater and estuarine systems are much less characterized. Additionally, different methodologies are utilized across the freshwater-marine continuum for measuring grazing rates, leading to comparative issues between measured grazing rates. This thesis investigated the use of major ion solutions (MIS) instead of filtered site water as the diluent for use in the oceanographic Landry-Hassett dilution grazing bioassay methodology to develop a common grazing method across the freshwater-marine continuum by running paired dilution grazing experiments in lake, river, estuarine (tidal and lagoonal), and oceanic shelf systems. As MIS doesn’t include vitamins that would be in filtered water, vitamin effects on grazing rate determination were also investigated. Results show that this revised grazing method can be applied across the freshwater-marine continuum.