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Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic
- Source :
- Science of The Total Environment. :195-205
- Publication Year :
- 2015
- Publisher :
- Elsevier BV, 2015.
-
Abstract
- In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ(13)C) and nitrogen (δ(15)N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ(13)C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ(15)N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota.
- Subjects :
- Aquatic Organisms
Canada
Food Chain
Environmental Engineering
Biomagnification
Zooplankton
chemistry.chemical_compound
Arctic char
Animals
Environmental Chemistry
14. Life underwater
Waste Management and Disposal
Methylmercury
biology
Arctic Regions
Ecology
Biota
Mercury
Plankton
biology.organism_classification
Pollution
Food web
Lakes
chemistry
13. Climate action
Benthic zone
Environmental chemistry
Environmental science
Water Pollutants, Chemical
Environmental Monitoring
Subjects
Details
- ISSN :
- 00489697
- Database :
- OpenAIRE
- Journal :
- Science of The Total Environment
- Accession number :
- edsair.doi.dedup.....0fcea8ff0105eddb52283dc647c2d53e