title: Differential bioaccumulation of potentially toxic elements in benthic and pelagic food chains in Lake Baikal.
abstract: Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low.
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491, Trondheim, Norway. tomasz.ciesielski@ntnu.no.
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Ciesielski
authors.affiliation: Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Science, Irkutsk, 664033, Russia.
authors.forename: Mikhail V
authors.initials: MV
authors.lastname: Pastukhov
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491, Trondheim, Norway.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Leeves
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491, Trondheim, Norway.|Department of Environmental Technology, SINTEF Materials and Chemistry, Brattørkaia 17c, 7010, Trondheim, Norway.
authors.forename: Julia
authors.initials: J
authors.lastname: Farkas
authors.affiliation: Department of Chemistry, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway.
authors.forename: Syverin
authors.initials: S
authors.lastname: Lierhagen
authors.affiliation: Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Science, Irkutsk, 664033, Russia.
authors.forename: Vera I
authors.initials: VI
authors.lastname: Poletaeva
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491, Trondheim, Norway.
authors.forename: Bjørn M
authors.initials: BM
authors.lastname: Jenssen
mesh_terms: D000818:Animals; D058448:Biota; D017753:Ecosystem; D005399:Fishes; D020387:Food Chain; D007448:Invertebrates / Q000737:chemistry; D060106:Lakes; D008628:Mercury / Q000032:analysis*; D010933:Plankton / Q000737:chemistry; D012800:Siberia; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury
keywords: Bioaccumulation; Chemical elements; Food chain; Lake Baikal; Pollution