| Autor: |
Tran, L., Reist, J. D., Gallagher, C. P., Power, M. |
| Předmět: |
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| Zdroj: |
Polar Biology; May2019, Vol. 42 Issue 5, p865-876, 12p, 4 Charts, 3 Graphs, 1 Map |
| Abstrakt: |
Given the importance of anadromous Northern Dolly Varden as a consumption staple for northern residents and the climate- and development-related impacts on total mercury (THg) concentrations, temporal changes in northern Dolly Varden THg concentrations were assessed between historical (1986–1988) and contemporary (2011–2013) periods from two rivers in the north-western Canadian Arctic. In the Rat River, mean THg changed from 79 ± 42 ng/g ww in 1986–1988 to 109 ± 44 ng/g ww in 2011–2013, while in the Firth River, THg changed from 126 ± 45 ng/g ww in 1986–1988 to 178 ± 47 ng/g ww in 2011–2012. Length adjusted values indicated increases in the Firth River were driven by the increased size of fish, but increases in the Rat River were not. After factoring in size, δ13C and δ15N, [THg] was found to be most influenced over time by fish size, but also significantly modified by temporal period and foodweb position. Relationships between log[THg] versus fork-length and log[THg] versus δ13C have remained constant over time in the Rat River, but not in the Firth River, while relationships between log[THg] versus δ15N have remained constant in the Firth River, but not in the Rat River. Changes in the significance and the slope of the relationships relating δ13C and δ15N to log[THg] suggests underlying bioaccumulative processes are temporally variant and will be sensitive to climate-driven changes in the aquatic environments within which fish live and feed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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