Best undergraduate dissertation

The 2015 Greenwich Forum Prize for the Best Undergraduate Dissertation has been won by Marine Geography graduate Holly Welsby for her MESci project 'Diatom-dominated biofilm mediation of silicon dynamics in the Severn Estuary’. This is the third year in a row that a Cardiff University EARTH student has won this prize.

The aim of the project was to consider silicon dynamics in the Severn Estuary and to determine the biological mediation effect of diatom-dominated biofilms. Holly's research involved sampling the biofilms on both coastlines of the Severn during the summer and winter of 2014. She extracted mini-cores of sediment which she used to determine the surface biomass, key diatom species and benthic biogenic silica concentrations. Relative primary productivity was assessed by chlorophyll fluorescence. In addition, the pore fluids were analysed for their benthic dissolved silicon and phosphorous concentrations. The study showed that the silicon fraction is mediated through biological use by diatoms, and shows spatial and temporal variations.