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Trophic relationships in an Arctic food web and implications for trace metal transfer.
Sci Total Environ. 2006 Jun 01; 362(1-3):103-23.ST

Abstract

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+Show Affiliations

Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775-7000, USA. ftld@uaf.eduNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

16387350

Citation

Dehn, Larissa-A, et al. "Trophic Relationships in an Arctic Food Web and Implications for Trace Metal Transfer." The Science of the Total Environment, vol. 362, no. 1-3, 2006, pp. 103-23.
Dehn LA, Follmann EH, Thomas DL, et al. Trophic relationships in an Arctic food web and implications for trace metal transfer. Sci Total Environ. 2006;362(1-3):103-23.
Dehn, L. A., Follmann, E. H., Thomas, D. L., Sheffield, G. G., Rosa, C., Duffy, L. K., & O'Hara, T. M. (2006). Trophic relationships in an Arctic food web and implications for trace metal transfer. The Science of the Total Environment, 362(1-3), 103-23.
Dehn LA, et al. Trophic Relationships in an Arctic Food Web and Implications for Trace Metal Transfer. Sci Total Environ. 2006 Jun 1;362(1-3):103-23. PubMed PMID: 16387350.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Trophic relationships in an Arctic food web and implications for trace metal transfer. AU - Dehn,Larissa-A, AU - Follmann,Erich H, AU - Thomas,Dana L, AU - Sheffield,Gay G, AU - Rosa,Cheryl, AU - Duffy,Lawrence K, AU - O'Hara,Todd M, Y1 - 2006/01/04/ PY - 2005/08/16/received PY - 2005/11/03/revised PY - 2005/11/05/accepted PY - 2006/1/3/pubmed PY - 2006/7/29/medline PY - 2006/1/3/entrez SP - 103 EP - 23 JF - The Science of the total environment JO - Sci Total Environ VL - 362 IS - 1-3 N2 - 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. SN - 0048-9697 UR - https://www.unboundmedicine.com/medline/citation/16387350/Trophic_relationships_in_an_Arctic_food_web_and_implications_for_trace_metal_transfer_ DB - PRIME DP - Unbound Medicine ER -