Distribution of trace elements in waters of the Zrmanja River estuary (eastern Adriatic coast, Croatia)

Abstract

This study aims to investigate the geochemical characteristics of waters of the highly stratified Zrmanja River estuary (eastern Adriatic coast, Croatia). For that purpose, data on salinity and distribution of 16 elements in surface and bottom water of the Zrmanja River estuary was used to assess the spatial variation of trace elements in the estuary water and to identify the main processes governing these variations. The composition of the investigated water was found to be determined primarily by natural factors. Mass concentration levels of dissolved elements were relatively low and typical for unpolluted waters and are considered to primarily reflect the geological and hydrogeological background of the catchment area. The distribution of element mass concentrations along the water column was found to primarily reflect different water masses, the river on the surface and sea at the bottom. Deviation from conservative behaviour for some elements in the bottom water is due to adsorption and desorption processes from the particulate phases.