title: Assessment of metal exposure, ecological status and required water quality monitoring strategies in small- to medium-size temperate rivers.
abstract: The present study was undertaken to obtain a better understanding of the seasonal variability of total dissolved metal/metalloid levels and physicochemical parameters within small- to medium-size freshwater ecosystems in temperate climate region. The research was conducted in four seasons in the Sutla River, medium-size polluted, and the Črnomerec Stream, small-size unpolluted watercourse in Croatia. In the Sutla River, characterized by the rural/industrial catchment, physicochemical parameters and total dissolved metal concentrations of 21 trace and 4 macro elements were analysed downstream of the point source of pollution, the glass production facility, indicating for the first time their variability across four seasons. Based on dissolved oxygen, total dissolved solids, nutrient concentrations, conductivity and total chemical oxygen demand, quality status of the Sutla River was good, but moderate to poor during summer, what was additionally confirmed by the highest levels of the most of 25 measured metals/metalloids in summer. Comparison with the reference small-size watercourse, the Črnomerec Stream, indicated significant anthropogenic impact on the Sutla River, most evident for Fe, Mn, Mo, Ni, Pb, Rb and Tl levels (3-70-fold higher in the Sutla River across all seasons). Generally, presented results indicated significant decrease of the water quality in the anthropogenically impacted small- to medium-size watercourses in summer, regarding physicochemical water parameters and total dissolved metal/metalloid concentrations, and pointed to significant seasonality of these parameters. Confirmed seasonality of river ecological status indicates that seasonal assessment represents a prerequisite for proper classification of the water quality in small- to medium-size temperate rivers.
authors.affiliation: a Division for Marine and Environmental Research , Ruđer Bošković Institute , Zagreb , Croatia.
authors.forename: Vlatka Filipović
authors.initials: VF
authors.lastname: Marijić
authors.affiliation: b Division of Zoology, Department of Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia.
authors.forename: Mirela Sertić
authors.initials: MS
authors.lastname: Perić
authors.affiliation: b Division of Zoology, Department of Biology, Faculty of Science , University of Zagreb , Zagreb , Croatia.
authors.forename: Renata Matoničkin
authors.initials: RM
authors.lastname: Kepčija
authors.affiliation: a Division for Marine and Environmental Research , Ruđer Bošković Institute , Zagreb , Croatia.
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Dragun
authors.affiliation: c Zagreb Zoological Garden , Zagreb , Croatia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Kovarik
authors.affiliation: c Zagreb Zoological Garden , Zagreb , Croatia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Gulin
authors.affiliation: a Division for Marine and Environmental Research , Ruđer Bošković Institute , Zagreb , Croatia.
authors.forename: Marijana
authors.initials: M
authors.lastname: Erk
mesh_terms: D057919:Biological Oxygen Demand Analysis; D017523:Croatia; D004463:Ecology; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry*; D005898:Glass; D007220:Industrial Waste / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D010100:Oxygen / Q000032:analysis; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D007220:Industrial Waste; D008670:Metals; D014874:Water Pollutants, Chemical; D010100:Oxygen
keywords: Anthropogenic impact; ecological status; glass production; macro elements; trace elements