Document Detail


Trophic relationships in an Arctic food web and implications for trace metal transfer.
MedLine Citation:
PMID:  16387350     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Tissues of subsistence-harvested Arctic mammals were analyzed for silver (Ag), cadmium (Cd), and total mercury (THg). Muscle (or total body homogenates of potential fish and invertebrate prey) was analyzed for stable carbon (delta13C) and nitrogen (delta15N) isotopes to establish trophic interactions within the Arctic food chain. Food web magnification factors (FWMFs) and biomagnification factors for selected predator-prey scenarios (BMFs) were calculated to describe pathways of heavy metals in the Alaskan Arctic. FWMFs in this study indicate that magnification of selected heavy metals in the Arctic food web is not significant. Biomagnification of Cd occurs mainly in kidneys; calculated BMFs are higher for hepatic THg than renal THg for all predator-prey scenarios with the exception of polar bears (Ursus maritimus). In bears, the accumulation of renal THg is approximately 6 times higher than in liver. Magnification of hepatic Ag is minimal for all selected predator-prey scenarios. Though polar bears occupy a higher trophic level than belugas (Delphinapterus leucas), based on delta15N, the metal concentrations are either not statistically different between the two species or lower for bears. Similarly, concentrations of renal and hepatic Cd are significantly lower or not statistically different in polar bears compared to ringed (Phoca hispida) and bearded seals (Erignathus barbatus), their primary prey. THg, on the other hand, increased significantly from seal to polar bear tissues. Mean delta15N was lowest in muscle of Arctic fox (Alopex lagopus) and foxes also show the lowest levels of Hg, Cd and Ag in liver and kidney compared to the other species analyzed. These values are in good agreement with a diet dominated by terrestrial prey. Metal deposition in animal tissues is strongly dependent on biological factors such as diet, age, sex, body condition and health, and caution should be taken when interpreting magnification of dynamic and actively regulated trace metals.
Authors:
Larissa-A Dehn; Erich H Follmann; Dana L Thomas; Gay G Sheffield; Cheryl Rosa; Lawrence K Duffy; Todd M O'Hara
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2006-01-04
Journal Detail:
Title:  The Science of the total environment     Volume:  362     ISSN:  0048-9697     ISO Abbreviation:  Sci. Total Environ.     Publication Date:  2006 Jun 
Date Detail:
Created Date:  2006-05-23     Completed Date:  2006-07-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0330500     Medline TA:  Sci Total Environ     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  103-23     Citation Subset:  IM    
Affiliation:
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7000, USA. ftld@uaf.edu
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MeSH Terms
Descriptor/Qualifier:
Alaska
Animals
Cadmium / analysis*,  metabolism
Carbon Isotopes
Environmental Monitoring
Food Chain*
Foxes
Kidney / chemistry
Liver / chemistry
Mercury / analysis*,  metabolism
Muscles / chemistry
Nitrogen Isotopes
Principal Component Analysis
Seals, Earless
Silver / analysis*,  metabolism
Ursidae
Walruses
Water Pollutants, Chemical / analysis*,  metabolism
Whales
Chemical
Reg. No./Substance:
0/Carbon Isotopes; 0/Nitrogen Isotopes; 0/Water Pollutants, Chemical; 7439-97-6/Mercury; 7440-22-4/Silver; 7440-43-9/Cadmium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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