title: Histopathology investigation on the Vardar chub (Squalius vardarensis) populations captured from the rivers impacted by mining activities.
abstract: Many natural freshwater ecosystems, especially in the north eastern Macedonia, are polluted with heavy metals, which are released by active mines. Long-term exposure to high levels of dissolved metals might result in increased metal bioaccumulation in organs of aquatic organisms, and consequently might cause various sub-toxic and toxic effects. The aim of this study was to assess the health of Vardar chub (Squalius vardarensis) inhabiting mining impacted rivers Zletovska and Kriva, in comparison with chub from the reference Bregalnica River. It was done by use of indicators of tissue damage (histopathology of liver and gonads) and general indicators of exposure to environmental stressors (condition factor, organo-somatic indices and external/internal macroscopic lesions). Histological assessment of gonads revealed good reproductive health in all three rivers, indicating high tolerance of gonads to contaminant exposure. Contrary, several external/internal lesions were more pronounced in chub from severely metal contaminated Zletovska River. Prevalence of hepatic lesions was also higher in mining impacted rivers (in Kriva, 70%; in Zletovska, 59%) compared to Bregalnica River (38%). The spectrum of histological lesions observed in chub liver varied from non-specific minor degenerative conditions, such as lymphocyte infiltration, fibrosis, parasites, granulomas and lipidosis, to extensive and/or more severe changes such as bile duct proliferation, necrosis, megalocytosis, light-dark hepatocytes and hepatocytes regeneration. The results of histopathological investigation for all three rivers showed clear signs of water contamination, especially prominent in mining influenced rivers. More research efforts should be devoted to study of environmental conditions and metal contamination in the mining impacted rivers worldwide, especially of their effects on health of local ichthyofauna.
authors.affiliation: Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss Cyril and Methodius University, Arhimedova 3, 1000 Skopje, Macedonia. Electronic address: majaj@pmf.ukim.mk.
authors.forename: Maja
authors.initials: M
authors.lastname: Jordanova
authors.affiliation: Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss Cyril and Methodius University, Arhimedova 3, 1000 Skopje, Macedonia. Electronic address: katerinarebok@yahoo.com.
authors.forename: Katerina
authors.initials: K
authors.lastname: Rebok
authors.affiliation: Ruđer Bošković Institute, Divison for Marine and Environmental Research, Laboratory for Biological Effects of Metals, Bijenička 54, 10002 Zagreb, Croatia. Electronic address: zdragun@irb.hr.
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Dragun
authors.affiliation: Ministry of Agriculture, Forestry and Water Economy, Hydrometeorological Administration, Division for Water, Air and Soil Quality Monitoring and Laboratory Analyses; Hydrobiology and Ecology Department, Skupi 28, 1000 Skopje, Macedonia. Electronic address: sheriban@meteo.gov.mk.
authors.forename: Sheriban
authors.initials: S
authors.lastname: Ramani
authors.affiliation: Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss Cyril and Methodius University, Arhimedova 3, 1000 Skopje, Macedonia.
authors.forename: Lozenka
authors.initials: L
authors.lastname: Ivanova
authors.affiliation: Institute of Animal Sciences, Ile Ilievski 92a, 1000 Skopje, Macedonia. Electronic address: vasilkostov@yahoo.com.
authors.forename: Vasil
authors.initials: V
authors.lastname: Kostov
authors.affiliation: Ruđer Bošković Institute, Divison for Marine and Environmental Research, Laboratory for Aquaculture and Pathology of Aquatic Organisms, Bijenička 54, 10002 Zagreb, Croatia. Electronic address: Damir.Valic@irb.hr.
authors.forename: Damir
authors.initials: D
authors.lastname: Valić
authors.affiliation: Ruđer Bošković Institute, Divison for Marine and Environmental Research, Laboratory for Biological Effects of Metals, Bijenička 54, 10002 Zagreb, Croatia. Electronic address: Nesrete.Krasnici@irb.hr.
authors.forename: Nesrete
authors.initials: N
authors.lastname: Krasnići
authors.affiliation: Ruđer Bošković Institute, Divison for Marine and Environmental Research, Laboratory for Biological Effects of Metals, Bijenička 54, 10002 Zagreb, Croatia. Electronic address: vfilip@irb.hr.
authors.forename: Vlatka
authors.initials: V
authors.lastname: Filipović Marijić
authors.affiliation: Ruđer Bošković Institute, Divison for Marine and Environmental Research, Laboratory for Aquaculture and Pathology of Aquatic Organisms, Bijenička 54, 10002 Zagreb, Croatia. Electronic address: kada@irb.hr.
authors.forename: Damir
authors.initials: D
authors.lastname: Kapetanović
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000033:anatomy & histology; D005260:Female; D008099:Liver / Q000187:drug effects* / Q000473:pathology; D008297:Male; D008670:Metals / Q000633:toxicity*; D008906:Mining; D010053:Ovary / Q000033:anatomy & histology / Q000187:drug effects; D045483:Rivers; D013737:Testis / Q000033:anatomy & histology / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical
keywords: Gonads; Histopathology; Liver; Metal contamination; Mining; Monitoring; Vardar chub