Dissolved Nutrient Behaviour along the Estuarine Salinity Gradient at the Gediz River Mouth (Aegean Sea, Turkey)

Authors: AYŞIN SÜZAL, NİHAYET BİZSEL, KEMAL CAN BİZSEL, YUSUF SİNAN HÜSREVOĞLU

Abstract: The Gediz River is the largest fresh water source for İzmir Bay. Several studies have been carried out on the river's physical and biogeochemical dynamics. However, there has not been a particular geographical focus on the mouth of the river. In this study, along the salinity gradient towards the bay in 2004 and 2005, the dissolved inorganic nutrients were seasonally measured at the river mouth. During the sampling period, the concentration of the constituents showed variability in the range of 0.04-156 \mu M for NO_3^-, 0.02-12 \mu M for NO_2^-, 0-237 \mu M for NH_4^+, 0.02-26 \mu M for PO_4^{3-}, and 1-293 \mu M for SiO_2, while the river discharge fluctuated between 5.2 and 123 m^3/s. Resulting highly contrasted salinity gradients between 0.29 and 39.62 psu significantly influenced the concentrations of dissolved inorganic nutrients. Furthermore, simultaneous sampling carried out over the entire bay area provided an opportunity to study the effects of the river on the bay during periods of maximum and minimum discharge.

Keywords: Nutrients, Salinity gradient, PCA, Gediz River, İzmir Bay

Full Text: PDF