Biogenic silica distrubitions in water column and sediment in the Iner Bay of Izmir

ABSTRACT BIOGENIC SILICA DISTRUBITIONS IN WATER COLUMN AND SEDIMENT IN THE INER BAY OF IZMIR Merks, Gizem MSc in Marine-Inland Water Sciences and Technology Supervisor: Prof. Dr. H. Baha BÜYÜKIŞIK January, 2017, 34 pages The aim of the thesis is to find the importance of the sediment in the dissolved silicate source with fluxes of biogenic silica, chlorofil α, carbon concentrations and reactif silica. To measure reactif silica fluxes, incubation experiments on board were conducted on core samples in acrylic tanks with sea water temperature held constant. Carbonate, chlorofil α, chlorophyll degradation products, organic carbon, biogenic silica and aluminium measurements are made. Evidence has been found to carbonate precipitation in the winter and summer months. Biogenic silica dissolution is affected negatively via carbonate sedimentation as fine grade particulates in winter and affected positively via coars grade particules from rivers runoff. The main factors controlling the reactif silica flux is calcium carbonate and biogenic silica. Other variables like organic carbon that make up the cement material also reduces the variations in the data. Reactif silica fluxes in the summer period are much higher compared to winter period was observed. Thus the reactif silica flux from sediment to overlaying water in summer period is the main process that provides the diatom dominance. Reactive Silica coming from rivers is extremely low compared to winter period. In the summer period which contributed much less reactif silica in the river, because of the lower primary productivity compared to the winter period and the silt size lithogenic contribution dominance, reactif silica flux enhancing effect of promoting the diatom growth, positive impact on public health and mussel gathering is come to the fore. Key Words: Biogenic silica, reactif silica flux, carbonate precipitation, Izmir Inner Bay.