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Eriksson CE, Roffler GH, Allen JM, Lewis A, Levi T. The origin, connectivity, and individual specialization of island wolves after deer extirpation. Ecol Evol 2024; 14:e11266. [PMID: 38633525 PMCID: PMC11021858 DOI: 10.1002/ece3.11266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/19/2024] Open
Abstract
Wolves are assumed to be ungulate obligates, however, a recently described pack on Pleasant Island, Alaska USA, is persisting on sea otters and other marine resources without ungulate prey, violating this long-held assumption. We address questions about these wolves regarding their origin and fate, degree of isolation, risk of inbreeding depression, and diet specialization by individual and sex. We applied DNA metabarcoding and genotyping by amplicon sequencing using 957 scats collected from 2016 to 2022, and reduced representation sequencing of tissue samples to establish a detailed understanding of Pleasant Island wolf ecology and compare them with adjacent mainland wolves. Dietary overlap was higher among individual wolves on Pleasant Island (Pianka's index mean 0.95 ± 0.03) compared to mainland wolves (0.70 ± 0.21). The individual diets of island wolves were dominated by sea otter, ranging from 40.6% to 63.2% weighted percent of occurrence (wPOO) (mean 55.5 ± 8.7). In contrast, individual mainland wolves primarily fed on ungulates (42.2 ± 21.3) or voles during a population outbreak (31.2 ± 23.2). We traced the origin of the Pleasant Island pack to a mainland pair that colonized around 2013 and produced several litters. After this breeding pair was killed, their female offspring and an immigrant male became the new breeders in 2019. We detected 20 individuals of which 8 (40%) were trapped and killed while two died of natural causes during the 6-year study. Except for the new breeding male, the pedigree analysis and genotype results showed no additional movement to or from the island, indicating limited dispersal but no evidence of inbreeding. Our findings suggest wolves exhibit more flexible foraging behavior than previously believed, and hunting strategies can substantially differ between individuals within or between packs. Nevertheless, anthropogenic and natural mortality combined with limited connectivity to the mainland may inhibit the continued persistence of Pleasant Island wolves.
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Affiliation(s)
- Charlotte E. Eriksson
- Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | - Gretchen H. Roffler
- Alaska Department of Fish and GameDivision of Wildlife ConservationDouglasAlaskaUSA
| | - Jennifer M. Allen
- Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
| | - Alex Lewis
- Alaska Department of Fish and GameDivision of Wildlife ConservationDouglasAlaskaUSA
| | - Taal Levi
- Department of Fisheries, Wildlife, and Conservation SciencesOregon State UniversityCorvallisOregonUSA
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2
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Peraza I, Chételat J, Richardson M, Jung TS, Awan M, Baryluk S, Dastoor A, Harrower W, Kukka PM, McClelland C, Mowat G, Pelletier N, Rodford C, Ryjkov A. Diet and landscape characteristics drive spatial patterns of mercury accumulation in a high-latitude terrestrial carnivore. PLoS One 2023; 18:e0285826. [PMID: 37186585 PMCID: PMC10184919 DOI: 10.1371/journal.pone.0285826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 05/02/2023] [Indexed: 05/17/2023] Open
Abstract
Limited information exists on mercury concentrations and environmental drivers of mercury bioaccumulation in high latitude terrestrial carnivores. Spatial patterns of mercury concentrations in wolverine (Gulo gulo, n = 419) were assessed across a 1,600,000 km2 study area in relation to landscape, climate, diet and biological factors in Arctic and boreal biomes of western Canada. Hydrogen stable isotope ratios were measured in wolverine hair from a subset of 80 animals to assess the spatial scale for characterizing environmental conditions of their habitat. Habitat characteristics were determined using GIS methods and raster datasets at two scales, the collection location point and a 150 km radius buffer, which was selected based on results of a correlation analysis between hydrogen stable isotopes in precipitation and wolverine hair. Total mercury concentrations in wolverine muscle ranged >2 orders of magnitude from 0.01 to 5.72 μg/g dry weight and varied geographically, with the highest concentrations in the Northwest Territories followed by Nunavut and Yukon. Regression models at both spatial scales indicated diet (based on nitrogen stable isotope ratios) was the strongest explanatory variable of mercury concentrations in wolverine, with smaller though statistically significant contributions from landscape variables (soil organic carbon, percent cover of wet area, percent cover of perennial snow-ice) and distance to the Arctic Ocean coast. The carbon and nitrogen stable isotope ratios of wolverine muscle suggested greater mercury bioaccumulation could be associated with feeding on marine biota in coastal habitats. Landscape variables identified in the modelling may reflect habitat conditions which support enhanced methylmercury transfer to terrestrial biota. Spatially-explicit estimates of wet atmospheric deposition were positively correlated with wolverine mercury concentrations but this variable was not selected in the final regression models. These landscape patterns provide a basis for further research on underlying processes enhancing methylmercury uptake in high latitude terrestrial food webs.
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Affiliation(s)
- Inés Peraza
- Geography and Environmental Studies, Carleton University, Ottawa, Ontario, Canada
| | - John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Murray Richardson
- Geography and Environmental Studies, Carleton University, Ottawa, Ontario, Canada
| | - Thomas S Jung
- Department of Environment, Government of Yukon, Whitehorse, Yukon, Canada
- Department of Renewable Resources, University of Alberta, Edmonton, Alberta, Canada
| | - Malik Awan
- Department of Environment, Government of Nunavut, Igloolik, Nunavut, Canada
| | - Steve Baryluk
- Environment and Natural Resources, Government of the Northwest Territories, Inuvik, Northwest Territories, Canada
| | - Ashu Dastoor
- Environment and Climate Change Canada, Air Quality Research Division, Dorval, Quebec, Canada
| | - William Harrower
- Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Piia M Kukka
- Department of Environment, Government of Yukon, Whitehorse, Yukon, Canada
| | - Christine McClelland
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Garth Mowat
- Ministry of Forests, British Columbia Government, Nelson, British Columbia, Canada
- Department of Earth, Environmental and Geographic Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Nicolas Pelletier
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Christine Rodford
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, Ontario, Canada
| | - Andrei Ryjkov
- Environment and Climate Change Canada, Air Quality Research Division, Dorval, Quebec, Canada
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3
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Jonsson S, Mastromonaco MN, Wang F, Bravo AG, Cairns WRL, Chételat J, Douglas TA, Lescord G, Ukonmaanaho L, Heimbürger-Boavida LE. Arctic methylmercury cycling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:157445. [PMID: 35882324 DOI: 10.1016/j.scitotenv.2022.157445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Anthropogenic mercury (Hg) undergoes long-range transport to the Arctic where some of it is transformed into methylmercury (MeHg), potentially leading to high exposure in some Arctic inhabitants and wildlife. The environmental exposure of Hg is determined not just by the amount of Hg entering the Arctic, but also by biogeochemical and ecological processes occurring in the Arctic. These processes affect MeHg uptake in biota by regulating the bioavailability, methylation and demethylation, bioaccumulation and biomagnification of MeHg in Arctic ecosystems. Here, we present a new budget for pools and fluxes of MeHg in the Arctic and review the scientific advances made in the last decade on processes leading to environmental exposure to Hg. Methylation and demethylation are key processes controlling the pool of MeHg available for bioaccumulation. Methylation of Hg occurs in diverse Arctic environments including permafrost, sediments and the ocean water column, and is primarily a process carried out by microorganisms. While microorganisms carrying the hgcAB gene pair (responsible for Hg methylation) have been identified in Arctic soils and thawing permafrost, the formation pathway of MeHg in oxic marine waters remains less clear. Hotspots for methylation of Hg in terrestrial environments include thermokarst wetlands, ponds and lakes. The shallow sub-surface enrichment of MeHg in the Arctic Ocean, in comparison to other marine systems, is a possible explanation for high MeHg concentrations in some Arctic biota. Bioconcentration of aqueous MeHg in bacteria and algae is a critical step in the transfer of Hg to top predators, which may be dampened or enhanced by the presence of organic matter. Variable trophic position has an important influence on MeHg concentrations among populations of top predator species such as ringed seal and polar bears distributed across the circumpolar Arctic. These scientific advances highlight key processes that affect the fate of anthropogenic Hg deposited to Arctic environments.
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Affiliation(s)
- Sofi Jonsson
- Department of Environmental Science, Stockholm University, SE-106 91 Stockholm, Sweden.
| | | | - Feiyue Wang
- Centre for Earth Observation Science, and Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Andrea G Bravo
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
| | - Warren R L Cairns
- CNR Institute of Polar Sciences and Ca' Foscari University, Venice, Italy
| | - John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
| | - Thomas A Douglas
- U.S. Army Cold Regions Research and Engineering Laboratory, Fort Wainwright, AK, USA
| | - Gretchen Lescord
- Wildlife Conservation Society Canada and Laurentian University, Vale Living with Lakes Center, Sudbury, Ontario, Canada
| | - Liisa Ukonmaanaho
- Natural Resources Institute Finland (Luke), P.O. Box 2, FI-00791 Helsinki, Finland
| | - Lars-Eric Heimbürger-Boavida
- CNRS/INSU,Aix Marseille Université,Université de Toulon, IRD, Mediterranean Institute of Oceanography (MIO), Marseille, France
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4
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Treu G, Sinding MHS, Czirják GÁ, Dietz R, Gräff T, Krone O, Marquard-Petersen U, Mikkelsen JB, Schulz R, Sonne C, Søndergaard J, Sun J, Zubrod J, Eulaers I. An assessment of mercury and its dietary drivers in fur of Arctic wolves from Greenland and High Arctic Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156171. [PMID: 35613645 DOI: 10.1016/j.scitotenv.2022.156171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Mercury has become a ubiquitous hazardous element even ending up in pristine areas such as the Arctic, where it biomagnifies and leaves especially top predators vulnerable to potential health effects. Here we investigate total mercury (THg) concentrations and dietary proxies for trophic position and habitat foraging (δ15N and δ13C, respectively) in fur of 30 Arctic wolves collected during 1869-1998 in the Canadian High Arctic and Greenland. Fur THg concentrations (mean ± SD) of 1.46 ± 1.39 μg g -1 dry weight are within the range of earlier reported values for other Arctic terrestrial species. Based on putative thresholds for Hg-mediated toxic health effects, the studied Arctic wolves have most likely not been at compromised health. Dietary proxies show high dietary plasticity among Arctic wolves deriving nutrition from both marine and terrestrial food sources at various trophic positions. Variability in THg concentrations seem to be related to the wolves' trophic position rather than to different carbon sources or regional differences (East Greenland, the Foxe Basin and Baffin Bay area, respectively). Although the present study remains limited due to the scarce, yet unique historic study material and small sample size, it provides novel information on temporal and spatial variation in Hg pollution of remote Arctic species.
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Affiliation(s)
- Gabriele Treu
- German Environment Agency, Department Chemicals, DE-06844 Dessau-Roßlau, Germany; Leibniz Institute for Zoo and Wildlife Research, Department of Wildlife Diseases, DE-10315 Berlin, Germany.
| | - Mikkel-Holger S Sinding
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark; Greenland Institute of Natural Resources, Kivioq 2, Nuuk, Greenland
| | - Gábor Á Czirják
- Leibniz Institute for Zoo and Wildlife Research, Department of Wildlife Diseases, DE-10315 Berlin, Germany
| | - Rune Dietz
- Department of Ecoscience, Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark
| | - Thomas Gräff
- German Environment Agency, Department Systems on Chemical Safety, DE-6844 Dessau-Roßlau, Germany
| | - Oliver Krone
- Leibniz Institute for Zoo and Wildlife Research, Department of Wildlife Diseases, DE-10315 Berlin, Germany
| | | | | | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, DE-76829 Landau, Germany
| | - Christian Sonne
- Department of Ecoscience, Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark
| | - Jens Søndergaard
- Department of Ecoscience, Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark
| | - Jiachen Sun
- College of Marine Life Sciences, Ocean University of China, CN-266003 Qingdao, China
| | - Jochen Zubrod
- iES Landau, Institute for Environmental Sciences, University of Koblenz-Landau, DE-76829 Landau, Germany; Zubrod Environmental Data Science, Friesenstrasse 20, 76829 Landau, Germany
| | - Igor Eulaers
- Department of Ecoscience, Arctic Research Centre, Aarhus University, DK-4000 Roskilde, Denmark; Fram Centre, Norwegian Polar Institute, NO-9296 Tromsø, Norway.
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5
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McKinney MA, Chételat J, Burke SM, Elliott KH, Fernie KJ, Houde M, Kahilainen KK, Letcher RJ, Morris AD, Muir DCG, Routti H, Yurkowski DJ. Climate change and mercury in the Arctic: Biotic interactions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155221. [PMID: 35427623 DOI: 10.1016/j.scitotenv.2022.155221] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/18/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Global climate change has led to profound alterations of the Arctic environment and ecosystems, with potential secondary effects on mercury (Hg) within Arctic biota. This review presents the current scientific evidence for impacts of direct physical climate change and indirect ecosystem change on Hg exposure and accumulation in Arctic terrestrial, freshwater, and marine organisms. As the marine environment is elevated in Hg compared to the terrestrial environment, terrestrial herbivores that now exploit coastal/marine foods when terrestrial plants are iced over may be exposed to higher Hg concentrations. Conversely, certain populations of predators, including Arctic foxes and polar bears, have shown lower Hg concentrations related to reduced sea ice-based foraging and increased land-based foraging. How climate change influences Hg in Arctic freshwater fishes is not clear, but for lacustrine populations it may depend on lake-specific conditions, including interrelated alterations in lake ice duration, turbidity, food web length and energy sources (benthic to pelagic), and growth dilution. In several marine mammal and seabird species, tissue Hg concentrations have shown correlations with climate and weather variables, including climate oscillation indices and sea ice trends; these findings suggest that wind, precipitation, and cryosphere changes that alter Hg transport and deposition are impacting Hg concentrations in Arctic marine organisms. Ecological changes, including northward range shifts of sub-Arctic species and altered body condition, have also been shown to affect Hg levels in some populations of Arctic marine species. Given the limited number of populations and species studied to date, especially within Arctic terrestrial and freshwater systems, further research is needed on climate-driven processes influencing Hg concentrations in Arctic ecosystems and their net effects. Long-term pan-Arctic monitoring programs should consider ancillary datasets on climate, weather, organism ecology and physiology to improve interpretation of spatial variation and time trends of Hg in Arctic biota.
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Affiliation(s)
- Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3 V9, Canada.
| | - John Chételat
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Samantha M Burke
- Minnow Aquatic Environmental Services, Guelph, ON N1H 1E9, Canada
| | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3 V9, Canada
| | - Kim J Fernie
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Magali Houde
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Montréal, QC H2Y 5E7, Canada
| | - Kimmo K Kahilainen
- Lammi Biological Station, University of Helsinki, FI-16900 Lammi, Finland
| | - Robert J Letcher
- Ecotoxicology & Wildlife Health, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Adam D Morris
- Northern Contaminants Program, Crown-Indigenous Relations and Northern Affairs Canada, Gatineau, QC J8X 2V6, Canada
| | - Derek C G Muir
- Aquatic Contaminants Research Division, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
| | - David J Yurkowski
- Arctic Aquatic Research Division, Fisheries and Oceans Canada, Winnipeg, MB R3T 2N6, Canada
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6
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Evans MN, Waller S, Müller CT, Goossens B, Smith JA, Bakar MSA, Kille P. The price of persistence: Assessing the drivers and health implications of metal levels in indicator carnivores inhabiting an agriculturally fragmented landscape. ENVIRONMENTAL RESEARCH 2022; 207:112216. [PMID: 34656630 DOI: 10.1016/j.envres.2021.112216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/17/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Patterns and practices of agricultural expansion threaten the persistence of global biodiversity. Wildlife species surviving large-scale land use changes can be exposed to a suite of contaminants that may deleteriously impact their health. There is a paucity of data concerning the ecotoxicological impacts associated with the global palm oil (Elaeis guineensis) industry. We sampled wild Malay civets (Viverra tangalunga) across a patchwork landscape degraded by oil palm agriculture in Sabah, Malaysian Borneo. Using a non-lethal methodology, we quantified the levels of 13 essential and non-essential metals within the hair of this adaptable small carnivore. We robustly assessed the biological and environmental drivers of intrapopulation variation in measured levels. Metal concentrations were associated with civet age, weight, proximity to a tributary, and access to oxbow lakes. In a targeted case study, the hair metal profiles of 16 GPS-collared male civets with differing space use patterns were contrasted. Civets that entered oil palm plantations expressed elevated aluminium, cadmium, and lead, and lower mercury hair concentrations compared to civets that remained exclusively within the forest. Finally, we paired hair metal concentrations with 34 blood-based health markers to evaluate the possible sub-lethal physiological effects associated with varied hair metal levels. Our multi-facetted approach establishes these adaptable carnivores as indicator species within an extensively altered ecosystem, and provides critical and timely evidence for future studies.
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Affiliation(s)
- Meaghan N Evans
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK; Danau Girang Field Centre, Kota Kinabalu, 88100, Malaysia.
| | - Simon Waller
- School of Chemistry, Cardiff University, Cardiff, CF10 3AT, UK
| | - Carsten T Müller
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
| | - Benoit Goossens
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK; Danau Girang Field Centre, Kota Kinabalu, 88100, Malaysia; Sustainable Places Institute, Cardiff University, Cardiff, CF10 3BA, UK; Sabah Wildlife Department, Kota Kinabalu, 88100, Malaysia
| | - Jeremy A Smith
- School of Applied Sciences, University of South Wales, CF37 4BB, UK
| | | | - Peter Kille
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK.
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7
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Clatterbuck CA, Lewison RL, Orben RA, Ackerman JT, Torres LG, Suryan RM, Warzybok P, Jahncke J, Shaffer SA. Foraging in marine habitats increases mercury concentrations in a generalist seabird. CHEMOSPHERE 2021; 279:130470. [PMID: 34134398 DOI: 10.1016/j.chemosphere.2021.130470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/28/2021] [Accepted: 03/30/2021] [Indexed: 06/12/2023]
Abstract
Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of differential foraging may be especially important for generalist species that exhibit high plasticity in foraging habitats, locations, or diet. Here, we investigate whether foraging habitat, sex, or fidelity to a foraging area impact blood mercury concentrations in western gulls (Larus occidentalis) from three colonies on the US west coast. Cluster analyses showed that nearly 70% of western gulls foraged primarily in ocean or coastal habitats, whereas the remaining gulls foraged in terrestrial and freshwater habitats. Gulls that foraged in ocean or coastal habitats for half or more of their foraging locations had 55% higher mercury concentrations than gulls that forage in freshwater and terrestrial habitats. Ocean-foraging gulls also had lower fidelity to a specific foraging area than freshwater and terrestrial-foraging gulls, but fidelity and sex were unrelated to gull blood mercury concentrations in all models. These findings support existing research that has described elevated mercury levels in species using aquatic habitats. Our analyses also demonstrate that gulls can be used to detect differences in contaminant exposure over broad geographic scales and across coarse habitat types, a factor that may influence gull health and persistence of other populations that forage across the land-sea gradient.
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Affiliation(s)
| | | | - Rachael A Orben
- Oregon State University, Department of Fisheries and Wildlife, Hatfield Marine Science Center, Newport, OR, USA
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, USA
| | - Leigh G Torres
- Oregon State University, Department of Fisheries and Wildlife, Marine Mammal Institute, Hatfield Marine Science Center, Newport, OR, USA
| | - Robert M Suryan
- Oregon State University, Department of Fisheries and Wildlife, Hatfield Marine Science Center, Newport, OR, USA
| | | | | | - Scott A Shaffer
- San José State University, Department of Biological Sciences, San Jose, CA, USA
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8
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Elliott KH, Braune BM, Elliott JE. Beyond bulk δ 15N: Combining a suite of stable isotopic measures improves the resolution of the food webs mediating contaminant signals across space, time and communities. ENVIRONMENT INTERNATIONAL 2021; 148:106370. [PMID: 33476789 DOI: 10.1016/j.envint.2020.106370] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/27/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
Top predators are used as indicators of contaminant trends across space and time. However, signals are integrated over complex food webs, and variation in diet may confound such signals. Trophic position, assessed by bulk δ15N, is widely used to infer the variation in diet relevant to contamination, yet a single variable cannot completely describe complex food webs. Thus, we examined relationships across three aquatic systems varying from a single species to a small food web using bulk values from four isotopes and 21 amino acid-specific values. Because variation in baseline ('source') δ15N can confound estimates of trophic position , we calculated trophic position from the difference between δ15Ntrophic (δ15N for amino acids that change with trophic position) and δ15Nsource (δ15N for amino acids that do not change with trophic position). Across all three systems, variation in δ15Nsource explained over half of the variation in bulk δ15N, and stable isotope values that reflected the base of the food web (δ13C, δ18O, δ34S) predicted contaminants as well or better than δ15N-which was supported by a meta-analysis of other studies. In ospreys feeding in lakes, variation in δ15Nsource across space created a spurious relationship between ΣDDT and apparent trophic position, and masked a relationship between ΣPCB and trophic position. In a seabird guild, changes in diet over time obscured temporal variation in contaminants over five decades. In Arctic fish and invertebrates, more accurate trophic magnification factors were calculated using δ15Ntrophic-source. Thus, (1) using δ15Ntrophic-source, instead of bulk δ15N, avoided incorrect conclusions and improved accuracy of trophic magnification factors necessary to assess risk to top predators; and (2) diet assessed with multiple spatial isotopes, rather than δ15N alone, was essential to understand patterns in contaminants across space, time and biological communities. Trophic position was most important for lipophilic 'legacy' contaminants (ΣDDT, ΣPCB) and habitat was most important for other contaminants (ΣPBDE, ΣPFAS, mercury). We argue that the use of amino acid-specific analysis of δ15N alongside 'non-trophic' isotopes should be a core feature of any study that examines the influence of trophic position on chemical pollution, as required for a chemical to be added to international conventions such as the Stockholm Convention.
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Affiliation(s)
- Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, Sainte Anne-de-Bellevue H9X 3V9, Canada.
| | - Birgit M Braune
- Science & Technology Branch, Environment and Climate Change Canada, Ottawa K1A 0H3, Canada
| | - John E Elliott
- Science & Technology Branch, Environment and Climate Change Canada, Delta V4K 3N2, Canada
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9
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Peterson SH, Ackerman JT, Hartman CA, Casazza ML, Feldheim CL, Herzog MP. Mercury exposure in mammalian mesopredators inhabiting a brackish marsh. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 273:115808. [PMID: 33497946 DOI: 10.1016/j.envpol.2020.115808] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/18/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Bioaccumulation of environmental contaminants in mammalian predators can serve as an indicator of ecosystem health. We examined mercury concentrations of raccoons (Procyon lotor; n = 37 individuals) and striped skunks (Mephitis mephitis; n = 87 individuals) in Suisun Marsh, California, a large brackish marsh that is characterized by contiguous tracts of tidal marsh and seasonally impounded wetlands. Mean (standard error; range) total mercury concentrations in adult hair grown from 2015 to 2018 were 28.50 μg/g dw (3.05 μg/g dw; range: 4.46-81.01 μg/g dw) in raccoons and 4.85 μg/g dw (0.54 μg/g dw; range: 1.53-27.02 μg/g dw) in striped skunks. We reviewed mammalian hair mercury concentrations in the literature and raccoon mercury concentrations in Suisun Marsh were among the highest observed for wild mammals. Although striped skunk hair mercury concentrations were 83% lower than raccoons, they were higher than proposed background levels for mercury in mesopredator hair (1-5 μg/g). Hair mercury concentrations in skunks and raccoons were not related to animal size, but mercury concentrations were higher in skunks in poorer body condition. Large inter-annual differences in hair mercury concentrations suggest that methylmercury exposure to mammalian predators varied among years. Mercury concentrations of raccoon hair grown in 2017 were 2.7 times greater than hair grown in 2015, 1.7 times greater than hair grown in 2016, and 1.6 times greater than hair grown in 2018. Annual mean raccoon and skunk hair mercury concentrations increased with wetland habitat area. Furthermore, during 2017, raccoon hair mercury concentrations increased with the proportion of raccoon home ranges that was wetted habitat, as quantified using global positioning system (GPS) collars. The elevated mercury concentrations we observed in raccoons and skunks suggest that other wildlife at similar or higher trophic positions may also be exposed to elevated methylmercury bioaccumulation in brackish marshes.
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Affiliation(s)
- Sarah H Peterson
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - C Alex Hartman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - Michael L Casazza
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
| | - Cliff L Feldheim
- California Department of Water Resources, 3500 Industrial Blvd #131, West Sacramento, CA 95691, USA
| | - Mark P Herzog
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive Suite D, Dixon, CA, 95620, USA
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10
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Carrasco-Rueda F, Loiselle BA, Frederick PC. Mercury bioaccumulation in tropical bats from a region of active artisanal and small-scale gold mining. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1032-1042. [PMID: 32323107 DOI: 10.1007/s10646-020-02195-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/13/2020] [Indexed: 06/11/2023]
Abstract
Mercury negatively affects human and animal health. Artisanal and small-scale gold mining can be a major local source of mercury contamination, especially into aquatic systems in tropical areas. Animals associated with mercury-contaminated aquatic systems are at high risk of experiencing effects of this heavy metal, but it is not clear how far the effects may extend into nearby terrestrial systems. We report mercury contamination levels in bats in agricultural areas at increasing distances from gold mining (~3-89 km of distance). We hypothesized that bat mercury concentrations would differ between feeding guilds, land use types, and be higher at sites closer to gold mining areas. We collected 112 fur samples from 30 bat species and eight guilds, and provide the first reports of concentrations in 12 species. All mercury concentrations were below the level at which health is likely to be affected (10 ppm). We found guild-influenced differences among mercury concentration levels, with the highest concentrations in aerial insectivores and carnivores, and the lowest in canopy frugivores. Our results suggest insectivorous and carnivorous bats may still be at some risk even at sites distant from aquatic mercury contamination. We did not find an effect of agricultural land-use type on mercury concentrations within species or guilds, suggesting mercury contamination did not extend to agricultural sites from areas of gold mining activities, and that these agricultural activities themselves were not an important source of mercury. We conclude bats did not demonstrate a signature of mercury risk either as a result of proximity of gold mining, or as a result of agricultural activities.
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Affiliation(s)
- Farah Carrasco-Rueda
- School of Natural Resources and Environment, University of Florida, 103 Black Hall, Gainesville, FL, 32611, USA.
- Keller Science Action Center, The Field Museum of Natural History, 1400 Lake Shore Drive, Chicago, IL, 60603, USA.
| | - Bette A Loiselle
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, FL, 32611, USA
- Center for Latin American Studies, University of Florida, 319 Grinter Hall, Gainesville, FL, 32611, USA
| | - Peter C Frederick
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, FL, 32611, USA
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11
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Shillito LM, Whelton HL, Blong JC, Jenkins DL, Connolly TJ, Bull ID. Pre-Clovis occupation of the Americas identified by human fecal biomarkers in coprolites from Paisley Caves, Oregon. SCIENCE ADVANCES 2020; 6:eaba6404. [PMID: 32743069 PMCID: PMC7363456 DOI: 10.1126/sciadv.aba6404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
When and how people first settled in the Americas is an ongoing area of research and debate. The earliest sites typically only contain lithic artifacts that cannot be directly dated. The lack of human skeletal remains in these early contexts means that alternative sources of evidence are needed. Coprolites, and the DNA contained within them, are one such source, but unresolved issues concerning ancient DNA taphonomy and potential for contamination make this approach problematic. Here, we use fecal lipid biomarkers to demonstrate unequivocally that three coprolites dated to pre-Clovis are human, raise questions over the reliance on DNA methods, and present a new radiocarbon date on basketry further supporting pre-Clovis human occupation.
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Affiliation(s)
- Lisa-Marie Shillito
- School of History, Classics and Archaeology, Armstrong Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Helen L. Whelton
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, UK
| | - John C. Blong
- School of History, Classics and Archaeology, Armstrong Building, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Dennis L. Jenkins
- Museum of Natural and Cultural History, University of Oregon, Eugene, OR 97403, USA
| | - Thomas J. Connolly
- Museum of Natural and Cultural History, University of Oregon, Eugene, OR 97403, USA
| | - Ian D. Bull
- Organic Geochemistry Unit, School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, UK
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12
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Chételat J, Ackerman JT, Eagles-Smith CA, Hebert CE. Methylmercury exposure in wildlife: A review of the ecological and physiological processes affecting contaminant concentrations and their interpretation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 711:135117. [PMID: 31831233 DOI: 10.1016/j.scitotenv.2019.135117] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 10/15/2019] [Accepted: 10/21/2019] [Indexed: 05/12/2023]
Abstract
Exposure to methylmercury (MeHg) can result in detrimental health effects in wildlife. With advances in ecological indicators and analytical techniques for measurement of MeHg in a variety of tissues, numerous processes have been identified that can influence MeHg concentrations in wildlife. This review presents a synthesis of theoretical principals and applied information for measuring MeHg exposure and interpreting MeHg concentrations in wildlife. Mercury concentrations in wildlife are the net result of ecological processes influencing dietary exposure combined with physiological processes that regulate assimilation, transformation, and elimination. Therefore, consideration of both physiological and ecological processes should be integrated when formulating biomonitoring strategies. Ecological indicators, particularly stable isotopes of carbon, nitrogen, and sulfur, compound-specific stable isotopes, and fatty acids, can be effective tools to evaluate dietary MeHg exposure. Animal species differ in their physiological capacity for MeHg elimination, and animal tissues can be inert or physiologically active, act as sites of storage, transformation, or excretion of MeHg, and vary in the timing of MeHg exposure they represent. Biological influences such as age, sex, maternal transfer, and growth or fasting are also relevant for interpretation of tissue MeHg concentrations. Wildlife tissues that represent current or near-term bioaccumulation and in which MeHg is the predominant mercury species (such as blood and eggs) are most effective for biomonitoring ecosystems and understanding landscape drivers of MeHg exposure. Further research is suggested to critically evaluate the use of keratinized external tissues to measure MeHg bioaccumulation, particularly for less-well studied wildlife such as reptiles and terrestrial mammals. Suggested methods are provided to effectively use wildlife for quantifying patterns and drivers of MeHg bioaccumulation over time and space, as well as for assessing the potential risk and toxicological effects of MeHg on wildlife.
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Affiliation(s)
- John Chételat
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, ON K1A 0H3, Canada.
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, Dixon Field Station, 800 Business Park Drive, Suite D, Dixon, CA 95620, United States
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, 3200 SW Jefferson Way, Corvallis, Oregon, 97331, United States
| | - Craig E Hebert
- Environment and Climate Change Canada, National Wildlife Research Centre, 1125 Colonel By Drive, Ottawa, ON K1A 0H3, Canada
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Cyr AP, López JA, Wooller MJ, Whiting A, Gerlach R, O'Hara T. Ecological drivers of mercury concentrations in fish species in subsistence harvests from Kotzebue Sound, Alaska. ENVIRONMENTAL RESEARCH 2019; 177:108622. [PMID: 31419713 DOI: 10.1016/j.envres.2019.108622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
The State of Alaska assesses human exposure to mercury (Hg) via fish consumption producing consumption guidelines for fish tailored for children and women of childbearing age. Under these guidelines, unrestricted consumption is suggested for many fish species, while limited consumption is recommended for others. Subsequent questions have arisen regarding ecological drivers influencing [Hg] in fishes consumed by Alaskans. This community-assisted public health study evaluates [Hg] in fishes from Kotzebue Sound to examine factors that may drive observed [Hg]. We examined eight species of subsistence harvested fish (least cisco, chum salmon, Pacific herring, humpback whitefish, sheefish, starry flounder, Pacific tomcod, and fourhorn sculpin) from Kotzebue Sound. We report total Hg concentrations ([THg]) and monomethyl Hg+ concentrations ([MeHg+]) in the context of various factors (such as species, fork length, carbon and nitrogen stable isotope (δ15N or δ13C)) values that may influence [Hg] and [MeHg+]. Across all 297 fish, [THg] ranged from 3.4 - 235.2 ng/g ww. [THg] was positively correlated with fork length in six of eight fish species, as well as with trophic level (indicated by δ15N values) in five species. [MeHg+] was positively correlated with fork length in four species, and with δ15N values over all specimens examined, and specifically for three individual species. In six of the seven species analyzed, %MeHg was >80% of [THg]. This value decreased with fork length in three species, with no relationship for δ15N values in any species. Among top ranked models based on Akaike Information Criterion correction (AICc), fork length was more frequently included as an explanatory factor for [Hg] than δ15N or δ13C values. The food web magnification factor for [THg] was 11.3, and 12.6 for [MeHg+]. Biomagnification is likely driving [THg] and [MeHg+] over the entire food web, while within species, bioaccumulation is likely a stronger driver of [THg] and [MeHg+] than feeding ecology or trophic position. The [THg] for all species fell within the established unrestricted consumption guideline of 200 ng/g weight wet as established by the State of Alaska's fish consumption guidelines for Hg.
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Affiliation(s)
- Andrew P Cyr
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Drive, Fairbanks, AK, 99775-7220, USA.
| | - J Andrés López
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Drive, Fairbanks, AK, 99775-7220, USA; University of Alaska Museum of the North, University of Alaska, Fairbanks, 907 Yukon Drive, Fairbanks, AK, 99775-6960, USA
| | - Matthew J Wooller
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Drive, Fairbanks, AK, 99775-7220, USA; Water and Environmental Research Center, Institute of Northern Engineering, 306 Tanana Loop, Fairbanks, AK, 99775-5860, USA; Alaska Stable Isotope Facility, University of Alaska, Fairbanks, 907 Yukon Drive, Fairbanks, AK, 99775-6960, USA
| | - Alex Whiting
- Native Village of Kotzebue, 600 Fifth Ave., Kotzebue, AK, 99752, USA
| | - Robert Gerlach
- Office of the State Veterinarian, Alaska Division of Environmental Health, 5251 Drive. Martin Luther King Jr. Ave., Anchorage, AK, 99507, USA
| | - Todd O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, 901 Koyukuk Drive, Fairbanks, AK, 99775-7750, USA
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14
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Cyr A, López JA, Rea L, Wooller MJ, Loomis T, Mcdermott S, O'Hara TM. Mercury concentrations in marine species from the Aleutian Islands: Spatial and biological determinants. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 664:761-770. [PMID: 30763856 DOI: 10.1016/j.scitotenv.2019.01.387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/21/2019] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Several species found in the Bering Sea show significant spatial variation in total mercury concentrations ([THg]) longitudinally along the Aleutian Island chain. We assessed [THg] in other members of the Bering Sea food web to better understand the factors shaping regional differences. [THg] and stable carbon and nitrogen isotope ratios (δ15N and δ13C values) were measured in muscle tissue from 1052 fishes and cephalopods from parts of the Bering Sea and North Pacific Ocean adjacent to the Aleutian Islands. The spatial distribution of the samples enabled regional comparisons for 8 species of fish and one species of cephalopod. Four species showed higher mean length-standardized [THg] in the western Aleutian Islands management area. [THg] in yellow Irish lord were very different relative to those observed in other species and when included in multi-species analyses drove the overall regional trends in mean [THg]. Multi-species analyses excluding measurements for yellow Irish lord showed mean length-standardized [THg] was greater in the western Aleutian Islands than in the central Aleutian Islands management area. Linear regression of [THg] and δ15N values showed a significant and positive relationship across all species, varying between regions and across species. Isotopic space of all species was significantly different between the western Aleutian Islands and central Aleutian Islands, driven largely by δ13C values. Stable isotope values observed follow the same regional trend of lower trophic taxa reported in the literature, with significantly lower δ13C values in the western Aleutian Islands. We conclude that there are regional differences in carbon and nitrogen stable isotope ecology, as well as species-specific feeding ecology that influence [THg] dynamics in part of the marine food web along the Aleutian Island chain. These regional differences are likely contributors to the observed regional variations of [THg] in some high-level predators found in these regions.
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Affiliation(s)
- Andrew Cyr
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Dr, Fairbanks, AK 99775-7220, USA.
| | - J Andrés López
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Dr, Fairbanks, AK 99775-7220, USA; University of Alaska Museum of the North, University of Alaska, Fairbanks, 907 Yukon Dr, Fairbanks, AK 99775-6960, USA
| | - Lorrie Rea
- Water and Environmental Research Center, 306 Tanana Loop, Fairbanks, AK 99775-5860, USA
| | - Matthew J Wooller
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Dr, Fairbanks, AK 99775-7220, USA; Water and Environmental Research Center, 306 Tanana Loop, Fairbanks, AK 99775-5860, USA; Alaska Stable Isotope Facility, University of Alaska, Fairbanks, 907 Yukon Dr, Fairbanks, AK 99775-6960, USA
| | - Todd Loomis
- Ocean Peace, Inc., 4201 21st Avenue West, Seattle, WA 98199, USA
| | - Susanne Mcdermott
- NOAA National Marine Fisheries Service, Alaska Fisheries Science Center, 7600 Sandpoint Way, NE (F/AKC2), Seattle, WA 98115, USA
| | - Todd M O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, 901 Koyukuk Drive, Fairbanks, AK 99775-7750, USA
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15
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Peterson SH, Ackerman JT, Crocker DE, Costa DP. Foraging and fasting can influence contaminant concentrations in animals: an example with mercury contamination in a free-ranging marine mammal. Proc Biol Sci 2019; 285:rspb.2017.2782. [PMID: 29436501 DOI: 10.1098/rspb.2017.2782] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 01/08/2018] [Indexed: 11/12/2022] Open
Abstract
Large fluctuations in animal body mass in relation to life-history events can influence contaminant concentrations and toxicological risk. We quantified mercury concentrations in adult northern elephant seals (Mirounga angustirostris) before and after lengthy at sea foraging trips (n = 89) or fasting periods on land (n = 27), and showed that mercury concentrations in blood and muscle changed in response to these events. The highest blood mercury concentrations were observed after the breeding fast, whereas the highest muscle mercury concentrations were observed when seals returned to land to moult. Mean female blood mercury concentrations decreased by 30% across each of the two annual foraging trips, demonstrating a foraging-associated dilution of mercury concentrations as seals gained mass. Blood mercury concentrations increased by 103% and 24% across the breeding and moulting fasts, respectively, demonstrating a fasting-associated concentration of mercury as seals lost mass. In contrast to blood, mercury concentrations in female's muscle increased by 19% during the post-breeding foraging trip and did not change during the post-moulting foraging trip. While fasting, female muscle mercury concentrations increased 26% during breeding, but decreased 14% during moulting. Consequently, regardless of exposure, an animal's contaminant concentration can be markedly influenced by their annual life-history events.
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Affiliation(s)
- Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA .,Institute of Marine Science, University of California, Santa Cruz, Santa Cruz, CA, USA.,US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, USA
| | - Joshua T Ackerman
- US Geological Survey, Western Ecological Research Center, Dixon Field Station, Dixon, CA, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
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16
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Herring G, Eagles-Smith CA, Varland DE. Mercury and lead exposure in avian scavengers from the Pacific Northwest suggest risks to California condors: Implications for reintroduction and recovery. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 243:610-619. [PMID: 30218871 DOI: 10.1016/j.envpol.2018.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/01/2018] [Accepted: 09/02/2018] [Indexed: 06/08/2023]
Abstract
Mercury (Hg) and lead (Pb) are widespread contaminants that pose risks to avian scavengers. In fact, Pb exposure is the primary factor limiting population recovery in the endangered California condor (Gymnogyps californianus) and Hg can impair avian reproduction at environmentally relevant exposures. The Pacific Northwest region of the US was historically part of the condor's native range, and efforts are underway to expand recovery into this area. To identify potential threats to reintroduced condors we assessed foraging habitats, Hg and Pb exposure, and physiological responses in two surrogate avian scavenger species (common ravens [Corvus corax] and turkey vultures [Cathartes aura] across the region between 2012 and 2016. Mercury exposure near the Pacific coast was 17-27-fold higher than in inland areas, and stable carbon and sulfur isotopes ratios indicated that coastal scavengers were highly reliant on marine prey. In contrast, Pb concentrations were uniformly elevated across the region, with 18% of the birds exposed to subclinical poisoning levels. Elevated Pb concentrations were associated with lower delta-aminolevulinic acid dehydratase (δ-ALAD) activity, and in ravens there was an interactive effect between Hg and Pb on fecal corticosterone concentrations. This interaction indicated that the effects of Hg and Pb exposure on the stress axis are bidirectional, and depend on the magnitude of simultaneous exposure to the other contaminant. Our results suggest that condors released to the Pacific Northwest may be exposed to both elevated Hg and Pb, posing challenges to management of future condor populations in the Pacific Northwest. Developing a robust monitoring program for reintroduced condors and surrogate scavengers will help both better understand the drivers of exposure and predict the likelihood of impaired health. These findings provide a strong foundation for such an effort, providing resource managers with valuable information to help mitigate potential risks.
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Affiliation(s)
- Garth Herring
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA
| | - Collin A Eagles-Smith
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, 97331, USA.
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17
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van den Brink NW, Scheiber IBR, de Jong ME, Braun A, Arini A, Basu N, van den Berg H, Komdeur J, Loonen MJJE. Mercury associated neurochemical response in Arctic barnacle goslings (Branta leucopsis). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:1052-1058. [PMID: 29929222 DOI: 10.1016/j.scitotenv.2017.12.191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/04/2017] [Accepted: 12/17/2017] [Indexed: 06/08/2023]
Affiliation(s)
- Nico W van den Brink
- Wageningen University, Div. Toxicology, Box 8000, 6700 EA Wageningen, The Netherlands.
| | - Isabella B R Scheiber
- University Groningen, Groningen Institute of Evolutionary Life Sciences, Behavioural and Physiological Ecology, PO. Box 11103, 9700 CC Groningen, The Netherlands
| | - Margje E de Jong
- Arctic Centre, University Groningen, P.O. Box 716, 9700 AS Groningen, The Netherlands
| | - Anna Braun
- University Groningen, Groningen Institute of Evolutionary Life Sciences, Behavioural and Physiological Ecology, PO. Box 11103, 9700 CC Groningen, The Netherlands
| | - Adeline Arini
- Faculty of Agricultural and Environmental Sciences, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | - Niladri Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec H9X 3V9, Canada
| | - Hans van den Berg
- Wageningen University, Div. Toxicology, Box 8000, 6700 EA Wageningen, The Netherlands
| | - Jan Komdeur
- University Groningen, Groningen Institute of Evolutionary Life Sciences, Behavioural and Physiological Ecology, PO. Box 11103, 9700 CC Groningen, The Netherlands
| | - Maarten J J E Loonen
- Arctic Centre, University Groningen, P.O. Box 716, 9700 AS Groningen, The Netherlands
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18
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Treu G, Krone O, Unnsteinsdóttir ER, Greenwood AD, Czirják GÁ. Correlations between hair and tissue mercury concentrations in Icelandic arctic foxes (Vulpes lagopus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 619-620:1589-1598. [PMID: 29107366 DOI: 10.1016/j.scitotenv.2017.10.143] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/14/2017] [Accepted: 10/14/2017] [Indexed: 06/07/2023]
Abstract
Monitoring organic pollutants in wildlife is a common approach to evaluate environmental health, chemical exposure and to make hazard assessments. However, pollutant concentrations measured from different tissue types among studies impede direct comparisons of levels and toxicity benchmarks among species and regions. For example, mercury (Hg) is a metal of both natural and anthropogenic origin which poses health risks for marine and arctic biota in particular. Although hair is recognized as the least invasive sample type for Hg exposure measurement in wildlife, measurements in previous studies have used different tissues among individuals and species. This lack of tissue type consistency hinders cross study comparisons. Therefore to systematically evaluate the use of hair in ecotoxicological studies, total mercury (THg) concentrations measured from hair were compared to values obtained from liver and kidney in 35 Icelandic arctic foxes (Vulpes lagopus). THg concentrations varied considerably among tissues with hair and kidney levels generally lower than in liver. Nevertheless, significant correlations among tissue types were observed. THg values in hair were predictive for liver (R2=0.61) and kidney THg levels (R2=0.51) and liver values were a good predictor of THg in kidney (R2=0.77). We provide further evidence that non-invasively collected hair samples reflect the THg levels of internal tissues. We present equations derived from multiple linear regression models that can be used to relate THg levels among tissue types in order to extrapolate THg values from hair to soft tissues. Using these equations, we compare the results of previous studies monitoring THg levels in different tissues of arctic foxes from various regions of the Arctic. Our findings support that hair is a suitable sample matrix for ecotoxicological studies of arctic predators and may be applied in both wildlife welfare and conservation contexts for arctic vulpine species.
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Affiliation(s)
- Gabriele Treu
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany.
| | - Oliver Krone
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany
| | | | - Alex D Greenwood
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany; Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Gábor Á Czirják
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Str. 17, 10315 Berlin, Germany.
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19
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Lazarus M, Sekovanić A, Orct T, Reljić S, Jurasović J, Huber Đ. Sexual Maturity and Life Stage Influences Toxic Metal Accumulation in Croatian Brown Bears. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 74:339-348. [PMID: 29230529 DOI: 10.1007/s00244-017-0487-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 11/27/2017] [Indexed: 06/07/2023]
Abstract
The influence of reproductive and (early) life stages on toxic metal levels was investigated in the brown bear (Ursus arctos), the largest mammalian predator species in Croatia. The purpose was to examine critical clusters in a population that might be at a higher risk of adverse health effects caused by metals as environmental contaminants. Levels of cadmium, mercury and lead in muscle, liver and kidney cortex of 325 male and 139 female bears, quantified by inductively coupled plasma mass spectrometry, were analysed according to distinct bear life stages (young: cub, yearling, subadult; mature: adult). Metal levels did not differ among sexes in young animals (< 4 years), except for mercury in muscles (higher in females), and adult females had higher cadmium and mercury. A trend of renal cadmium accumulation with age in immature male animals disappeared once they reached maturity, whereas for females this trend has only slowly declined in mature compared to immature bears. In early life stage (< 1 year), bear cubs had lower cadmium, comparable mercury, and higher lead in the kidneys than the bears of the following age category (yearlings). Due to a higher proportion of renal lead transfer from the mother to the cub compared with cadmium, it may be that the high burden of cadmium found in kidneys of older females has lower toxicological concern for their cubs than the lead content. Sex, reproductive, and life stages of bears were confirmed as important in assessing toxic metal burden.
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Affiliation(s)
- Maja Lazarus
- Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, 10000, Zagreb, Croatia.
| | - Ankica Sekovanić
- Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, 10000, Zagreb, Croatia
| | - Tatjana Orct
- Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, 10000, Zagreb, Croatia
| | - Slaven Reljić
- Department of Biology, Veterinary Faculty, University of Zagreb, Heinzelova 55, 10000, Zagreb, Croatia
| | - Jasna Jurasović
- Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, P.O. Box 291, 10000, Zagreb, Croatia
| | - Đuro Huber
- Department of Biology, Veterinary Faculty, University of Zagreb, Heinzelova 55, 10000, Zagreb, Croatia
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20
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Use of Blood-soaked Cellulose Filter Paper for Measuring Carbon and Nitrogen Stable Isotopes. J Wildl Dis 2018; 54:375-379. [PMID: 29369725 DOI: 10.7589/2017-08-202] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We explored the use of filter paper soaked in whole blood for measuring carbon (C) and nitrogen (N) stable isotopes, often used in feeding ecology or diet studies, to better understand drivers of exposure to contaminants. Our results showed no statistically or biologically relevant differences in C and N stable isotope measures between our gold standard (whole blood with anticoagulant) and eluates from processed, blood-soaked filter paper. Our data supported the effectiveness of using filter paper for assessing C and N stable isotopes in blood to address feeding ecology and other uses. The ease of sampling and processing should allow blood-soaked filter paper to be used in sampling of live (e.g., captured, stranded) and lethally taken (e.g., hunter-killed) wild vertebrates.
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Cyr A, Sergeant CJ, Lopez JA, O'Hara T. Assessing the influence of migration barriers and feeding ecology on total mercury concentrations in Dolly Varden (Salvelinus malma) from a glaciated and non-glaciated stream. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 580:710-718. [PMID: 27979620 DOI: 10.1016/j.scitotenv.2016.12.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 06/06/2023]
Abstract
Assimilation of mercury (Hg) into food webs is directly influenced by ecological factors such as local habitat characteristics, species feeding behavior, and movement patterns. Total Hg concentrations ([THg]) in biota from Subarctic latitudes are driven both by broad spatial processes such as long-range atmospheric transport and more local influences such as biovectors and geology. Thus, even relatively pristine protected lands such as national parks are experiencing Hg accumulation. We analyzed [THg] and stable isotopes of carbon (δ13C) and nitrogen (δ15N) in 104 Dolly Varden (Salvelinus malma) collected from two rivers in southeastern Alaska, upstream and downstream of apparent anadromous migration barriers in watersheds with and without glacial coverage. To assess the potential magnitude of marine-derived THg returning to freshwater, we analyzed [THg] in ten adult pink salmon from each study system. There were no differences in Dolly Varden mean [THg] between sites after the data were standardized for fork length, but unadjusted [THg] varied relative to fish size and δ15N values. While previous studies generally show that [THg] increases with higher δ15N values, we found that Dolly Varden below migration barriers and foraging on salmon eggs had the highest δ15N values among all sampled individuals, but the lowest [THg]. Dolly Varden residing below anadromous barriers had δ13C values consistent with marine influence. Since salmon eggs typically have low [Hg], our results suggest that abundant salmon populations and the dietary subsidy they provide may reduce the annual exposure to [Hg] in egg-eating stream fishes such as Dolly Varden. In addition to identifying a suitable species for freshwater Hg monitoring in southeastern Alaska, our study more broadly implies that river characteristics, location within a river, fish size, and feeding ecology are important factors influencing Hg accumulation.
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Affiliation(s)
- Andrew Cyr
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Dr, Fairbanks, AK 99775-7220, USA.
| | - Christopher J Sergeant
- National Park Service, Inventory and Monitoring Program, 3100 National Park Road, Juneau 99801, AK, USA
| | - Juan Andres Lopez
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, 905 N Koyukuk Dr, Fairbanks, AK 99775-7220, USA; University of Alaska Museum of the North, University of Alaska Fairbanks, 907 Yukon Dr, Fairbanks, AK 99775-6960, USA
| | - Todd O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, 901 Koyukuk Dr, Fairbanks, AK 99775-7750, USA
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Peterson SH, Ackerman JT, Costa DP. Mercury correlations among blood, muscle, and hair of northern elephant seals during the breeding and molting fasts. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:2103-2110. [PMID: 26757244 DOI: 10.1002/etc.3365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 12/09/2015] [Accepted: 01/07/2016] [Indexed: 06/05/2023]
Abstract
Mercury (Hg) biomonitoring and toxicological risk assessments for marine mammals commonly sample different tissues, making comparisons with toxicity benchmarks and among species and regions difficult. Few studies have examined how life-history events, such as fasting, influence the relationship between total Hg (THg) concentrations in different tissues. The authors evaluated the relationships between THg concentrations in blood, muscle, and hair of female and male northern elephant seals (Mirounga angustirostris) at the start and end of the breeding and molting fasts. The relationships between tissues varied among tissue pairs and differed by sampling period and sex. Blood and muscle were generally related at all time periods; however, hair, an inert tissue, did not strongly represent the metabolically active tissues (blood and muscle) at all times of year. The strongest relationships between THg concentrations in hair and those in blood or muscle were observed during periods of active hair growth (end of the molting period) or during time periods when internal body conditions were similar to those when the hair was grown (end of the breeding fast). The results indicate that THg concentrations in blood or muscle can be translated to the other tissue type using the equations developed but that THg concentrations in hair were generally a poor index of internal THg concentrations except during the end of fasting periods. Environ Toxicol Chem 2016;35:2103-2110. © 2016 SETAC.
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Affiliation(s)
- Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, USA
| | - Joshua T Ackerman
- Dixon Field Station, Western Ecological Research Center, US Geological Survey, Dixon, California, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, California, USA
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23
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Harley JR, Bammler TK, Farin FM, Beyer RP, Kavanagh TJ, Dunlap KL, Knott KK, Ylitalo GM, O'Hara TM. Using Domestic and Free-Ranging Arctic Canid Models for Environmental Molecular Toxicology Research. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:1990-1999. [PMID: 26730740 PMCID: PMC5290708 DOI: 10.1021/acs.est.5b04396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The use of sentinel species for population and ecosystem health assessments has been advocated as part of a One Health perspective. The Arctic is experiencing rapid change, including climate and environmental shifts, as well as increased resource development, which will alter exposure of biota to environmental agents of disease. Arctic canid species have wide geographic ranges and feeding ecologies and are often exposed to high concentrations of both terrestrial and marine-based contaminants. The domestic dog (Canis lupus familiaris) has been used in biomedical research for a number of years and has been advocated as a sentinel for human health due to its proximity to humans and, in some instances, similar diet. Exploiting the potential of molecular tools for describing the toxicogenomics of Arctic canids is critical for their development as biomedical models as well as environmental sentinels. Here, we present three approaches analyzing toxicogenomics of Arctic contaminants in both domestic and free-ranging canids (Arctic fox, Vulpes lagopus). We describe a number of confounding variables that must be addressed when conducting toxicogenomics studies in canid and other mammalian models. The ability for canids to act as models for Arctic molecular toxicology research is unique and significant for advancing our understanding and expanding the tool box for assessing the changing landscape of environmental agents of disease in the Arctic.
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Affiliation(s)
- John R. Harley
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, 900 Yukon Drive Room 194, Fairbanks, Alaska 99775-6160, United States
| | - Theo K. Bammler
- Center for Ecogenetics and Environmental Health, Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE #100, Seattle, Washington 98105 United States
| | - Federico M. Farin
- Center for Ecogenetics and Environmental Health, Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE #100, Seattle, Washington 98105 United States
| | - Richard P. Beyer
- Center for Ecogenetics and Environmental Health, Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE #100, Seattle, Washington 98105 United States
| | - Terrance J. Kavanagh
- Center for Ecogenetics and Environmental Health, Department of Environmental and Occupational Health Sciences, University of Washington, 4225 Roosevelt Way NE #100, Seattle, Washington 98105 United States
| | - Kriya L. Dunlap
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, 900 Yukon Drive Room 194, Fairbanks, Alaska 99775-6160, United States
| | - Katrina K. Knott
- Memphis Zoo, 2000 Prentiss Place, Memphis, Tennessee 38112, United States
| | - Gina M. Ylitalo
- Environmental Fisheries and Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 2725 Montlake Boulevard E. Seattle, Washington 98112-2013, United States
| | - Todd M. O'Hara
- Department of Veterinary Medicine, University of Alaska, Fairbanks, 901 Koyukuk Dr, Fairbanks, Alaska 99775-7750, United States
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McGrew AK, O'Hara TM, Stricker CA, Margaret Castellini J, Beckmen KB, Salman MD, Ballweber LR. Ecotoxicoparasitology: Understanding mercury concentrations in gut contents, intestinal helminths and host tissues of Alaskan gray wolves (Canis lupus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 536:866-871. [PMID: 26283618 PMCID: PMC4807146 DOI: 10.1016/j.scitotenv.2015.07.106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 07/22/2015] [Accepted: 07/23/2015] [Indexed: 05/15/2023]
Abstract
Some gastrointestinal helminths acquire nutrients from the lumen contents in which they live; thus, they may be exposed to non-essential elements, such as mercury (Hg), during feeding. The objectives of this study were: 1) determine the total mercury concentrations ([THg]) in Gray wolves (Canis lupus) and their parasites, and 2) use stable isotopes to evaluate the trophic relationships within the host. [THg] and stable isotopes (C and N) were determined for helminths, host tissues, and lumen contents from 88 wolves. Sixty-three wolves contained grossly visible helminths (71.5%). The prevalence of taeniids and ascarids was 63.6% (56/88) and 20.5% (18/88), respectively. Nine of these 63 wolves contained both taeniids and ascarids (14.3%). All ascarids were determined to be Toxascaris leonina. Taenia species present included T. krabbei and T. hydatigena. Within the GI tract, [THg] in the lumen contents of the proximal small intestine were significantly lower than in the distal small intestine. There was a significant positive association between hepatic and taeniid [THg]. Bioaccumulation factors (BAF) ranged from <1 to 22.9 in taeniids, and 1.1 to 12.3 in T. leonina. Taeniid and ascarid BAF were significantly higher than 1, suggesting that both groups are capable of THg accumulation in their wolf host. δ13C in taeniids was significantly lower than in host liver and skeletal muscle. [THg] in helminths and host tissues, in conjunction with stable isotope (C and N) values, provides insight into food-web dynamics of the host GI tract, and aids in elucidating ecotoxicoparasitologic relationships. Variation of [THg] throughout the GI tract, and between parasitic groups, underscores the need to further evaluate the effect(s) of feeding niche, and the nutritional needs of parasites, as they relate to toxicant exposure and distribution within the host.
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Affiliation(s)
- Ashley K McGrew
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619, USA
| | - Todd M O'Hara
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619, USA; Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Craig A Stricker
- U. S. Geological Survey, Fort Collins Science Center, Denver, CO 80225, USA
| | - J Margaret Castellini
- Wildlife Toxicology Laboratory, Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | | | - Mo D Salman
- Animal Population Health Institute, Department of Clinical Sciences, Colorado State University, Fort Collins, CO 80523-1644, USA
| | - Lora R Ballweber
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1619, USA
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25
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Dainowski BH, Duffy LK, McIntyre J, Jones P. Hair and bone as predictors of tissular mercury concentration in the western Alaska red fox, Vulpes vulpes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 518-519:526-33. [PMID: 25777958 PMCID: PMC4404022 DOI: 10.1016/j.scitotenv.2015.03.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 03/03/2015] [Accepted: 03/03/2015] [Indexed: 05/11/2023]
Abstract
We evaluated if total mercury (THg) concentrations of keratin-based and bone-based tissues can predict THg concentrations in skeletal muscle, renal medulla, renal cortex, and liver. The THg concentration in matched tissues of 65 red foxes, Vulpes vulpes, from western Alaska was determined. Hair THg concentration had a significant positive correlation with liver, renal medulla, renal cortex, and muscle. The THg concentration for males and females is moderately predictive of THg concentration in the renal cortex and liver for these foxes based on R(2) values (R(2)=0.61 and 0.63, respectively). Bone is weakly predictive of THg concentration in muscle (R(2)=0.40), but not a reliable tissue to predict THg concentration in liver (R(2)=0.24), renal cortex (R(2)=0.35), or renal medulla (R(2)=0.25). These results confirm the potential use of trapped animals, specifically foxes, as useful Arctic sentinel species to inform researchers about patterns in THg levels over time as industrialization of the Arctic continues.
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Affiliation(s)
- B H Dainowski
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, United States.
| | - L K Duffy
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, United States.
| | - J McIntyre
- Department of Mathematics and Statistics, University of Alaska Fairbanks, Fairbanks, AK 99775, United States.
| | - P Jones
- Alaksa Department of Fish and Game, Bethel, AK 99559, United States
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Solgi E, Ghasempouri SM. Application of brown bear (Ursus arctos) records for retrospective assessment of mercury. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2015; 78:342-351. [PMID: 25734629 DOI: 10.1080/15287394.2014.968816] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Because mercury (Hg) is released into the atmosphere, wildlife living in habitats located far from point sources of metal may still be at risk. Mercury accumulation, previously considered a risk for aquatic ecosystems, is also found in many wildlife terrestrial species. The aim of the present study was to examine total Hg concentrations in the brown bear (Ursus arctos) by measurement of metal in hair from museum collections in Iran. Another objective of this investigation was to characterize the risk of Hg exposure in bears in several parts of Iran. Brown bear (Ursus arctos) hair samples (n = 35) were collected from 14 provinces in Iran for analysis of Hg contamination, performed using an advanced mercury analyzer (model Leco 254 AMA, USA) according to ASTM standard D-6722. Total Hg levels in Iranian bears from all areas ranged from 115.81 to 505.82 μg/kg, with a mean of 193.39 ng/g. Mercury concentrations in brown bear hair from different provinces in Iran were as follows in descending order: Khorasan Razavi > Esfahan > Khozestan > Yazd > Lorestan > Charmahalva Bakhtiari > Bushehr > Mazandaran > Markazi > Tehran > Ardebil > Gilan > East Azerbaijan. The highest content of Hg was found in the south (206.62 ± 31.95 ng/g), whereas the lowest levels were detected in the west (167.71 ± 32.97 ng/g). Overall total Hg content in bear hair was below harmful levels for this species. A decreasing trend was noted in the period 1986-2006, which may be mainly due to reduction of global Hg emissions. Data suggest that food habits and habitat are two important factors that influence Hg accumulation in bears.
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Affiliation(s)
- Eisa Solgi
- a Department of Environment, Faculty of Natural Resources and Environment , Malayer University , Hamedan , Iran
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27
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McHuron EA, Harvey JT, Castellini JM, Stricker CA, O'Hara TM. Selenium and mercury concentrations in harbor seals (Phoca vitulina) from central California: health implications in an urbanized estuary. MARINE POLLUTION BULLETIN 2014; 83:48-57. [PMID: 24823685 DOI: 10.1016/j.marpolbul.2014.04.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 04/12/2014] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
We measured total selenium and total mercury concentrations ([TSe] and [THg]) in hair (n=138) and blood (n=73) of harbor seals (Phoca vitulina) from California to assess variation by geography and sex, and inferred feeding relationships based on carbon, nitrogen, and sulfur stable isotopes. Harbor seals from Hg-contaminated sites had significantly greater [THg], and lesser [TSe] and TSe:THg molar ratios than seals from a relatively uncontaminated site. Males had significantly greater [THg] than females at all locations. Sulfur stable isotope values explained approximately 25% of the variability in [THg], indicating increased Hg exposure for seals with a greater use of estuarine prey species. Decreased [TSe] in harbor seals from Hg-contaminated regions may indicate a relative Se deficiency to mitigate the toxic effects of Hg. Further investigation into the Se status and the potential negative impact of Hg on harbor seals from Hg-contaminated sites is warranted.
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Affiliation(s)
- Elizabeth A McHuron
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA.
| | - James T Harvey
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA
| | - J Margaret Castellini
- Institute of Marine Science, School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, P.O. Box 757220, Fairbanks, AK 99775-7220, USA
| | - Craig A Stricker
- U.S. Geological Survey, Fort Collins Science Center, Denver Federal Center, Building 21, MS963, Denver, CO 80225, USA
| | - Todd M O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, P.O. Box 755940, Fairbanks, AK 99775-7000, USA
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