Stable sulfur isotopes identify habitat-specific foraging and mercury exposure in a highly mobile fish community.

Autor: Carr MK; University of Saskatchewan, School of Environment and Sustainability, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada. Electronic address: meghan.carr@usask.ca., Jardine TD; University of Saskatchewan, School of Environment and Sustainability, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Toxicology Centre, Saskatoon, SK S7N5B3, Canada., Doig LE; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Toxicology Centre, Saskatoon, SK S7N5B3, Canada., Jones PD; University of Saskatchewan, School of Environment and Sustainability, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Toxicology Centre, Saskatoon, SK S7N5B3, Canada., Bharadwaj L; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Toxicology Centre, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, School of Public Health, Saskatoon, SK S7N5B3, Canada., Tendler B; University of Saskatchewan, Toxicology Centre, Saskatoon, SK S7N5B3, Canada., Chételat J; Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON K1A0H3, Canada., Cott P; University of Alberta, Department of Renewable Resources, Edmonton, AB T6G2R3, Canada., Lindenschmidt KE; University of Saskatchewan, School of Environment and Sustainability, Saskatoon, SK S7N5B3, Canada; University of Saskatchewan, Global Institute for Water Security, Saskatoon, SK S7N5B3, Canada.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2017 May 15; Vol. 586, pp. 338-346. Date of Electronic Publication: 2017 Feb 10.
DOI: 10.1016/j.scitotenv.2017.02.013
Abstrakt: Tracking the uptake and transfer of toxic chemicals, such as mercury (Hg), in aquatic systems is challenging when many top predators are highly mobile and may therefore be exposed to chemicals in areas other than their location of capture, confounding interpretation of bioaccumulation trends. Here we show how the application of a less commonly used ecological tracer, stable sulfur isotope ratios ( 34 S/ 32 S, or δ 34 S), in a large river-delta-lake complex in northern Canada allows differentiation of resident from migrant fishes, beyond what was possible with more conventional 13 C/ 12 C and 15 N/ 14 N measurements. Though all large fishes (n=105) were captured in the river, the majority (76%) had δ 34 S values that were indicative of the fish having been reared in the lake. These migrant fishes were connected to a food chain with greater Hg trophic magnification relative to the resident fish of the river and delta. Yet, despite a shallower overall trophic magnification slope, large river-resident fish had higher Hg concentrations owing to a greater biomagnification of Hg between small and large fishes. These findings reveal how S isotopes can trace fish feeding habitats in large freshwater systems and better account for fish movement in complex landscapes with differential exposure pathways and conditions.
(Copyright © 2017 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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