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Peterson SH, Peterson MG, Ackerman JT, Debier C, Goetsch C, Holser RR, Hückstädt LA, Johnson JC, Keates TR, McDonald BI, McHuron EA, Costa DP. Foraging behavior and age affect maternal transfer of mercury to northern elephant seal pups. Sci Rep 2024; 14:4693. [PMID: 38409311 PMCID: PMC10897339 DOI: 10.1038/s41598-024-54527-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 02/13/2024] [Indexed: 02/28/2024] Open
Abstract
Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes). Mercury concentrations in lanugo (hair grown in utero) were among the highest observed worldwide for young pinnipeds (geometric mean 23.01 μg/g dw, range 8.03-63.09 μg/g dw; n = 373); thus, some pups may be at an elevated risk of sub-lethal adverse health effects. Fetal mercury exposure was affected by maternal foraging geographic location and depth; mercury concentrations were highest in pups of the deepest diving, pelagic females. Moreover, pup lanugo mercury concentrations were strongly repeatable among successive pups of individual females, demonstrating relative consistency in pup mercury exposure based on maternal foraging strategies. Northern elephant seals are biosentinels of a remote deep-sea ecosystem. Our results suggest that mercury within North Pacific mesopelagic food webs may also pose an elevated risk to other mesopelagic-foraging predators and their offspring.
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Affiliation(s)
- Sarah H Peterson
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA.
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA.
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Michael G Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Joshua T Ackerman
- Western Ecological Research Center, Dixon Field Station, U.S. Geological Survey, 800 Business Park Drive Suite D, Dixon, CA, USA
| | - Cathy Debier
- Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Chandra Goetsch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- CSS, Inc, Fairfax, VA, USA
| | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
| | - Jennifer C Johnson
- Moss Landing Marine Labs, San Jose State University, Moss Landing, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | | | - Elizabeth A McHuron
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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Symon TE, Murillo-Cisneros DA, Hernández-Camacho CJ, O'Hara TM, Taylor RJ, Rosado-Berrios CA, Vázquez-Medina JP, Zenteno-Savín T. Mercury and selenium concentrations in lanugo of free-ranging California sea lions in the southern Gulf of California, Mexico. MARINE POLLUTION BULLETIN 2023; 197:115712. [PMID: 37922756 DOI: 10.1016/j.marpolbul.2023.115712] [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: 08/28/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023]
Abstract
Total mercury ([THg]) and selenium ([TSe]) concentrations were determined in California sea lion (Zalophus californianus) lanugo from the Gulf of California in 2021 and 2022. Relationships with sex, morphometrics, and year were evaluated. Following toxicological thresholds of concern for piscivorous mammals, most pups had a [THg] < 10 ppm, one pup (2021) had a [THg] > 20 ppm, no pups had a [THg] > 30 ppm. Females had significantly higher [TSe] than males; sex did not influence [THg]. [THg] and [TSe] in 2022 were significantly higher in the general population and male cohorts compared to 2021. Significant negative correlations were observed between [THg], [TSe], and morphometrics (2021). These results indicate that, compared to other pinniped species, regional California sea lions may have a decreased likelihood of experiencing Hg-related adverse health effects. Year-related changes in element concentrations suggest continued monitoring of this population to assess pinniped, environmental, and potentially, human health.
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Affiliation(s)
- T E Symon
- Centro de Investigaciones Biológicas del Noroeste, S. C (CIBNOR), 23096 La Paz, Mexico.
| | - D A Murillo-Cisneros
- Centro de Investigaciones Biológicas del Noroeste, S. C (CIBNOR), 23096 La Paz, Mexico.
| | - C J Hernández-Camacho
- Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, 23096 La Paz, Mexico.
| | - T M O'Hara
- School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station 77843, United States of America.
| | - R J Taylor
- School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station 77843, United States of America.
| | - C A Rosado-Berrios
- School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station 77843, United States of America.
| | - J P Vázquez-Medina
- Department of Integrative Biology, University of California, Berkeley, 94720 Berkeley, United States of America.
| | - T Zenteno-Savín
- Centro de Investigaciones Biológicas del Noroeste, S. C (CIBNOR), 23096 La Paz, Mexico.
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Taylor S, Terkildsen M, McQuilty R, Lee D, Wing-Simpson A, Gray R. Non-essential heavy metals and protective effects of selenium against mercury toxicity in endangered Australian sea lion (Neophoca cinerea) pups with hookworm disease. ENVIRONMENT INTERNATIONAL 2022; 169:107521. [PMID: 36148712 DOI: 10.1016/j.envint.2022.107521] [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: 05/28/2022] [Revised: 08/06/2022] [Accepted: 09/11/2022] [Indexed: 06/16/2023]
Abstract
The endangered Australian sea lion, Neophoca cinerea, faces ongoing population decline. Identification of key threats to N. cinerea population recovery, including disease and pollutants, is an objective of the species' recovery plan. Previous studies have identified Uncinaria sanguinis, an intestinal nematode, as a significant cause of disease and mortality in N. cinerea pups. Given the impact of heavy metals on the immune response, investigation of these pollutants is critical. To this end, the concentrations of arsenic (As), total mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb) and selenium (Se) were determined in blood collected from N. cinerea pups sampled during the 2017/18, 2019 and 2020/21 breeding seasons at Seal Bay Conservation Park, South Australia. Significant differences (p < 0.05) in Hg, As, Cr, and Se concentrations and molar ratio of Se:Hg were seen between breeding seasons. Pup age, maternal parity and inter-individual foraging behaviour were considered factors driving these differences. The concentrations of Hg (357, 198 and 241 µg/L) and As (225, 834 and 608 µg/L) were high in 2017/18, 2019 and 2020/21 respectively with Hg concentrations in the blood of N. cinerea pups above toxicological thresholds reported for marine mammals. The concentration of Se (1332, 647, 763 µg/L) and molar ratio of Se:Hg (9.47, 7.98 and 6.82) were low compared to other pinniped pups, indicating potential vulnerability of pups to the toxic effects of Hg. Significant (p < 0.05) negative associations for Pb and Cd with several red blood cell parameters suggest they could be exacerbating the anaemia caused by hookworm disease. Temporal (age-related) changes in element concentrations were also seen, such that pup age needs to be considered when interpreting bioaccumulation patterns. Further investigation of the role of elevated heavy metal concentrations on N. cinerea pup health, disease and development is recommended, particularly with respect to immunological impacts.
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Affiliation(s)
- Shannon Taylor
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia
| | | | - Robert McQuilty
- Department of Chemical Pathology, Royal Prince Alfred Hospital, Camperdown, Sydney 2050, Australia
| | - David Lee
- Department of Chemical Pathology, Royal Prince Alfred Hospital, Camperdown, Sydney 2050, Australia
| | - Aileen Wing-Simpson
- Department of Chemical Pathology, Royal Prince Alfred Hospital, Camperdown, Sydney 2050, Australia
| | - Rachael Gray
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camperdown, NSW 2006, Australia.
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Reindl AR, Saniewska D, Grajewska A, Falkowska L, Saniewski M. Alimentary exposure and elimination routes of rare earth elements (REE) in marine mammals from the Baltic Sea and Antarctic coast. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141947. [PMID: 32916487 DOI: 10.1016/j.scitotenv.2020.141947] [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: 05/12/2020] [Revised: 08/22/2020] [Accepted: 08/22/2020] [Indexed: 06/11/2023]
Abstract
Marine mammals found at the top of the trophic pyramid are excellent bioindicators of pollutants in the marine environment, the concentrations of which increase along with the trophic level of the organism. As these animals are usually protected species, their contamination has to be assessed non-invasively by analysing excrement and epidermal structures such as fur or claws. The present study involved testing the excrement and fur of the grey seal (Halichoerus grypus) from the Southern Baltic coast and the Southern elephant seal (Mirounga leonine) from Admiralty Bay, along with fish muscle (food) and the lithological background of both areas, for the presence of rare earth elements (REE). The soil on the Baltic coast is characterized by the predomination of light rare earth elements (LREE): yttrium, lanthanum and cerium (∑REE = 7.86 mg·kg-1 dw). In the soil and bedrock of Admiralty Bay all REEs were found except for terbium, thulium and lutetium (∑REE = 96.1 mg·kg-1 dw). The REE levels found in the muscles of Baltic herring (∑REE = 0.057 mg·kg-1 ww) were lower than those in the muscles of marbled rockcod (∑REE = 0.540 mg·kg-1 ww). The situation was analogous in the mammals, with the REE concentrations in grey seal fur (∑REE = 0.489 mg·kg-1 dw) and excrement (∑REE = 0.676 mg·kg-1 dw) being lower than those found in the fur (∑REE = 10.1 mg·kg-1 dw) and excrement (∑REE = 83.6 mg·kg-1 dw) of the elephant seal. The LREE/HREE partition coefficients in the grey seal excrement (3.37) and its fur (4.00), but also in the faeces of the elephant seal (2.63) and its fur (2.65), indicate that in each species the process of elimination from the body occurs in similar proportions.
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Affiliation(s)
- Andrzej R Reindl
- University of Gdansk, Faculty of Oceanography and Geography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Dominika Saniewska
- University of Gdansk, Faculty of Oceanography and Geography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Agnieszka Grajewska
- Institute of Meteorology and Water Management - National Research Institute, Waszyngtona 42 Str., 81-342 Gdynia, Poland.
| | - Lucyna Falkowska
- University of Gdansk, Faculty of Oceanography and Geography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Michał Saniewski
- Institute of Meteorology and Water Management - National Research Institute, Waszyngtona 42 Str., 81-342 Gdynia, Poland
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5
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Rea LD, Castellini JM, Avery JP, Fadely BS, Burkanov VN, Rehberg MJ, O'Hara TM. Regional variations and drivers of mercury and selenium concentrations in Steller sea lions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140787. [PMID: 32717470 DOI: 10.1016/j.scitotenv.2020.140787] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/01/2020] [Accepted: 07/04/2020] [Indexed: 06/11/2023]
Abstract
Mercury (Hg) can be neurotoxic to mammals and impact reproduction, whereas selenium (Se) is an important antioxidant known to ameliorate some adverse effects of Hg. Total Hg concentrations ([THg]) were measured in lanugo (pelage grown in utero) of 812 Steller sea lion (Eumetopias jubatus) pups across Alaska and Russia to assess fetal exposure during late gestation. The molar ratio of total Se to THg (TSe:THg) was determined in whole blood collected from 291 pups. Stable isotope ratios of carbon and nitrogen were measured in sections of vibrissae (whiskers, n = 498) and in lanugo (n = 480) of pups grown during late gestation to track diet variations among adult females that can drive Hg and Se exposure during this critical fetal development period. Lanugo [THg] ranged from 1.4 to 73.7 μg/g dry weight with the lowest median [THg] in Southeast Alaska. Pups from the Western Aleutian Islands had higher median lanugo [THg] than pups from other metapopulations in Alaska. Over 25% of pups in the Western Aleutian Islands had [THg] above published risk thresholds (20 μg/g) for other mammals. Whole blood molar TSe:THg was significantly lower in the Western Aleutian Islands and in some parts of the Central Aleutian Islands with higher molar ratios found in the Eastern Aleutian Islands and Central Gulf of Alaska. This suggests a limitation on potential protective functions of Se in the western regions with the highest relative [THg]. The Central Aleutian Island pups with [THg] over 20 μg/g had higher δ15N ratios than pups with lower [THg] suggesting dams consuming higher trophic level prey is a key driver for Hg exposure. However, regional differences likely reflect variability in diet of the dam during gestation and in Hg food web dynamics between oceanic regimes east and west of key passes in the Aleutian Islands.
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Affiliation(s)
- L D Rea
- Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA; Alaska Department of Fish and Game, Division of Wildlife Conservation, Anchorage, AK 99518, USA.
| | - J M Castellini
- Department of Veterinary Medicine, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - J P Avery
- Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - B S Fadely
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115, USA.
| | - V N Burkanov
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, WA 98115, USA; Kamchatka Branch of the Pacific Geographical Institute, Far East Branch of Russian Academy of Sciences, 6 Partizanskaya Street, Petropavlovsk-Kamchatsky 683000, Russia.
| | - M J Rehberg
- Alaska Department of Fish and Game, Division of Wildlife Conservation, Anchorage, AK 99518, USA.
| | - T M O'Hara
- Department of Veterinary Medicine, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, Fairbanks, AK 99775, USA; Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
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6
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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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7
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Levin M, Jasperse L, Desforges JP, O'Hara T, Rea L, Castellini JM, Maniscalco JM, Fadely B, Keogh M. Methyl mercury (MeHg) in vitro exposure alters mitogen-induced lymphocyte proliferation and cytokine expression in Steller sea lion (Eumetopias jubatus) pups. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138308. [PMID: 32302832 DOI: 10.1016/j.scitotenv.2020.138308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/23/2020] [Accepted: 03/28/2020] [Indexed: 06/11/2023]
Abstract
Steller sea lions (Eumetopias jubatus, SSLs) are managed as two distinct population segments within U.S. waters: the endangered western distinct population segment and the recently delisted eastern distinct population segment. Recent studies reported concentrations of mercury in several tissues collected from young SSLs in the Aleutian Islands that were at or above concentrations found to negatively impact health in other fish-eating mammals. However, there are limited studies which have investigated the range of mercury concentrations that may negatively influence the SSL immune system. This study assessed relationships between methyl mercury (MeHg+) concentrations and two immune functions, lymphocyte proliferation and cytokine expression. Peripheral blood mononuclear cells (PBMCs) were isolated and cryopreserved from pups on three rookeries within the western distinct population segment: Chiswell Island, Ulak, and Agattu Islands. Lymphocyte proliferation and cytokine expression were assessed in vitro using thawed PBMCs with exposure to MeHg+ (unexposed control, 0.001, 0.01, and 0.1 μg/ml). Lymphocyte proliferation was measured without and with stimulation with a T cell mitogen (ConA) and B cell mitogen (LPS) and the concentration of cytokines was measured in the cell culture supernatant (with and without ConA or LPS). Spontaneous lymphocyte proliferation was significantly increased at 0.01 and 0.1 μg/ml. T lymphocyte proliferation was significantly increased at 0.001 μg/ml and 0.1 μg/ml, while B lymphocyte proliferation was decreased at 0.1 μg/ml. Cytokine concentrations for INFγ, IL-10, IL-6, and TNFα were reduced at 0.1 μg/ml upon either T or B cell mitogen stimulation, with the exception for IL-10, where 0.1 μg/ml reduced IL-10 concentration compared to unstimulated cells. These data suggest immune functions were affected by MeHg+ exposure requiring in vivo follow up investigations. The observed modulation of immune functions is of concern as any toxicant-induced modulation may adversely affect the health of individuals, particularly younger animals undergoing periods of critical development.
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Affiliation(s)
- Milton Levin
- University of Connecticut, Department of Pathobiology and Veterinary Science, 61 N. Eagleville Road U-3089, Storrs, CT 06269, United States of America.
| | - Lindsay Jasperse
- University of Connecticut, Department of Pathobiology and Veterinary Science, 61 N. Eagleville Road U-3089, Storrs, CT 06269, United States of America
| | - Jean-Pierre Desforges
- Department of Bioscience, Arctic Research Centre, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Todd O'Hara
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775-5910, United States of America; Veterinary Integrative Biosciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 4458 TAMU, College Station, TX 77843, United States of America
| | - Lorrie Rea
- Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775-5910, United States of America
| | - J Margaret Castellini
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775-5910, United States of America
| | - John M Maniscalco
- Alaska SeaLife Center, P.O. Box 1329, Seward, AK 99664, United States of America
| | - Brian Fadely
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, United States of America
| | - Mandy Keogh
- Alaska Department of Fish and Game, Marine Mammal Program. 1300 College Rd., Fairbanks, AK 99701, United States of America
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Grajewska A, Falkowska L, Saniewska D, Pawliczka I. Fur and faeces - Routes of mercury elimination in the Baltic grey seal (Halichoerus grypus grypus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137050. [PMID: 32062253 DOI: 10.1016/j.scitotenv.2020.137050] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 01/29/2020] [Accepted: 01/30/2020] [Indexed: 06/10/2023]
Abstract
This study focused on evaluating the elimination of Hg by Baltic grey seals (Halichoerus grypus grypus) via faeces and pelage. In addition, we investigated the potential for ecosystem contamination via these routes. Faeces and fur were collected in 2014-2017 from captive adult grey seals and their pups. The concentrations of total mercury (THg) and methylmercury (MeHg) were measured in the samples. The amount of mercury eliminated in a labile form (the sum of the bioavailable Hg(II) and methylmercury) was also determined. An adult seal removed about 46% of mercury supplied with food via the faeces, of which only 17% was MeHg. Considering that mercury is mainly supplied to the body as MeHg, it can be assumed that mercury excreted along with faeces has undergone transformation inside the animal body. Despite the much higher THg and MeHg concentrations measured in fur, the incorporation of mercury into newly formed fur is a less effective method of Hg elimination removing just 4% of mercury entering the body via the alimentary route. The presence of mercury in lanugo is evidence of maternal transfer. First droppings of the pups were characterised by the highest content of MeHg and a low THg concentration. Then, despite the limited supply of mercury with food, and the rapid growth of the pup, the concentration of THg increased, suggesting that mercury started to be transformed into less toxic forms. It was estimated that faeces and fur expelled by seals could deliver about 800 g of mercury to the Baltic Sea. For both faeces and fur, most of the mercury (>95% for excrements and >85% for fur) was expelled in a labile form that can be quickly recycled.
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Affiliation(s)
- Agnieszka Grajewska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
| | - Lucyna Falkowska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Dominika Saniewska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Iwona Pawliczka
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Professor Krzysztof Skóra Hel Marine Station, ul. Morska 2, 84-150 Hel, Poland
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9
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Grajewska A, Falkowska L, Saniewska D, Pawliczka I. Changes in total mercury, methylmercury, and selenium blood levels during different life history stages of the Baltic grey seal (Halichoerus grypus grypus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 676:268-277. [PMID: 31048158 DOI: 10.1016/j.scitotenv.2019.04.204] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 06/09/2023]
Abstract
Using the blood of grey seal pups, the blood and milk of female grey seals inhabiting the Hel Marine Station of Gdansk University's Institute of Oceanography (HMS), we monitored the transfer of total mercury (THg), methylmercury (MeHg), and selenium (Se) with blood during foetal life and nursing. Changes in the concentration of mercury and selenium were characterised in the pups' blood during their first three months of life when they transition from suckling, to a post-weaning fast, to eating fish. In the blood of pregnant females, there was a significant decrease in THg and MeHg concentrations throughout the gestation, indicating the transfer of these toxins through the placenta into the foetus. At no other stage of the pup's development was there such a high level of THg and MeHg as on the day of birth, despite the incorporation of mercury into the lanugo during foetal growth. This suggests that the maternal transfer of mercury during gestation may be the time of greatest mercury exposure for a young seal pup. The consumption of milk caused a rapid increase in weight and a lowering of the mercury level in the blood in the subsequent days of the pups' life. The postweaning fast was the period of the lowest mercury concentration. The switch to a diet consisting of fish caused a systematic increase in the concentration of mercury in the blood of the pups. Milk was the significant source of selenium for pups and the selenium concentration in females' blood was reduced during lactation. The nursing period seemed to have the greatest impact on the mercury and selenium blood levels in examined seals. Natural development of the grey seal pup created an opportunity to decrease the levels of toxic substances obtained through the maternal transfer during foetal growth.
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Affiliation(s)
- Agnieszka Grajewska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
| | - Lucyna Falkowska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Dominika Saniewska
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland
| | - Iwona Pawliczka
- University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Professor Krzysztof Skóra Hel Marine Station, ul. Morska 2, 84-150 Hel, Poland
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Trukhin AM, Kalinchuk VV. Hair mercury concentrations in the spotted seal (Phoca largha) pups from the Sea of Japan. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:27133-27140. [PMID: 30022391 DOI: 10.1007/s11356-018-2731-6] [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: 03/23/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
This publication presents the results of a study of the total mercury (THg) concentration in the fetal hair (lanugo) of the young spotted seals inhabiting the Peter the Great Bay, Sea of Japan. We analyzed samples from pups that were collected in 2014-2017 at the seal breeding grounds. The concentration of total mercury was determined by atomic absorption spectrometry. The concentration of THg ranged from 1.52 to 6.68 μg/g dry weight. Mercury concentration in the lanugo exceeds that found in the environment (bottom sediments, sea water) and in other animals inhabiting the Bay. At the same time, the level was generally lower than that found in young seals of most other pinniped species (Steller sea lion Eumetopias jubatus, Northern fur seal Callorhinus ursinus, Harbor seal Phoca vitulina richardsi, Northern elephant seal Mirounga angustirostris, California sea lion Zalophus californianus) from the North Pacific.
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Affiliation(s)
- Alexey M Trukhin
- V.I.Il'ichev Pacific Oceanological Institute, FEB RAS, 43, Baltiyskaya Street, Vladivostok, Russia, 6900041.
| | - Viktor V Kalinchuk
- V.I.Il'ichev Pacific Oceanological Institute, FEB RAS, 43, Baltiyskaya Street, Vladivostok, Russia, 6900041
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11
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Bentzen R, Castellini JM, Gerlach R, Dykstra C, O'Hara T. Mercury concentrations in Alaska Pacific halibut muscle relative to stable isotopes of C and N and other biological variables. MARINE POLLUTION BULLETIN 2016; 113:110-116. [PMID: 27612930 DOI: 10.1016/j.marpolbul.2016.08.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 07/12/2016] [Accepted: 08/26/2016] [Indexed: 06/06/2023]
Abstract
Total mercury concentrations ([THg]), δ15N and δ13C values were determined in muscle of 693 Pacific halibut caught in International Pacific Halibut Commission setline surveys in Alaska (2002-2011). Project goals were to evaluate whether 1) δ15N and δ13C varied with region, age, sex and length of halibut, and 2) muscle [THg] varied with δ15N and δ13C (feeding ecology) while accounting for sex, length, and region. Variation in [THg] was explained, in part, by halibut feeding ecology as [THg] increased with trophic position (increasing δ15N). Halibut from the western Aleutian Island region were the exception, with overall lower δ15N values and significantly higher [THg] than halibut from other Alaskan waters. This [THg] pattern has been observed in other Aleutian biota, possibly the result of northeasterly atmospheric movement of mercury emissions from Asia and/or other local sources and processes. The significantly lower δ15N values for these halibut warrants further investigation of halibut prey.
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Affiliation(s)
- Rebecca Bentzen
- Institute of Arctic Biology, P.O. Box 757000, University of Alaska Fairbanks, Fairbanks, AK 99775-7000, USA; Arctic Beringia Program, Wildlife Conservation Society, P.O. Box 751110, Fairbanks, AK 99775, USA.
| | - J Margaret Castellini
- Department of Veterinary Medicine, P.O. Box 757750, University of Alaska Fairbanks, Fairbanks, AK 99775-7750, USA.
| | - Robert Gerlach
- Office of the State Veterinarian, Alaska Dept. of Environmental Conservation, 5251 Dr. Martin Luther King Jr. Ave., Anchorage, AK 99507, USA.
| | - Claude Dykstra
- International Pacific Halibut Commission, 2320 W. Commodore Way, Suite 300, Seattle, WA 98199-1287, USA.
| | - Todd O'Hara
- Department of Veterinary Medicine, P.O. Box 757750, University of Alaska Fairbanks, Fairbanks, AK 99775-7750, USA.
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12
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McHuron EA, Peterson SH, Ackerman JT, Melin SR, Harris JD, Costa DP. Effects of Age, Colony, and Sex on Mercury Concentrations in California Sea Lions. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 70:46-55. [PMID: 26259982 DOI: 10.1007/s00244-015-0201-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Accepted: 07/27/2015] [Indexed: 06/04/2023]
Abstract
We measured total mercury (THg) concentrations in California sea lions (Zalophus californianus) and examined how concentrations varied with age class, colony, and sex. Because Hg exposure is primarily via diet, we used nitrogen (δ (15)N) and carbon (δ (13)C) stable isotopes to determine if intraspecific differences in THg concentrations could be explained by feeding ecology. Blood and hair were collected from 21 adult females and 57 juveniles from three colonies in central and southern California (San Nicolas, San Miguel, and Año Nuevo Islands). Total Hg concentrations ranged from 0.01 to 0.31 μg g(-1) wet weight (ww) in blood and 0.74 to 21.00 μg g(-1) dry weight (dw) in hair. Adult females had greater mean THg concentrations than juveniles in blood (0.15 vs. 0.03 μg(-1) ww) and hair (10.10 vs. 3.25 μg(-1) dw). Age class differences in THg concentrations did not appear to be driven by trophic level or habitat type because there were no differences in δ (15)N or δ (13)C values between adults and juveniles. Total Hg concentrations in adult females were 54 % (blood) and 24 % (hair) greater in females from San Miguel than females from San Nicolas Island, which may have been because sea lions from the two islands foraged in different areas. For juveniles, we detected some differences in THg concentrations with colony and sex, although these were likely due to sampling effects and not ecological differences. Overall, THg concentrations in California sea lions were within the range documented for other marine mammals and were generally below toxicity benchmarks for fish-eating wildlife.
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Affiliation(s)
- Elizabeth A McHuron
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA, 95060, USA.
| | - Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA, 95060, USA
| | - Joshua T Ackerman
- U.S. Geological Survey, Western Ecological Research Center, 800 Business Park Drive, Suite D, Dixon, CA, 95620, USA
| | - Sharon R Melin
- National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA, 98155, USA
| | - Jeffrey D Harris
- National Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA, 98155, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, 100 Shaffer Road, Santa Cruz, CA, 95060, USA
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Noël M, Jeffries S, Lambourn DM, Telmer K, Macdonald R, Ross PS. Mercury Accumulation in Harbour Seals from the Northeastern Pacific Ocean: The Role of Transplacental Transfer, Lactation, Age and Location. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 70:56-66. [PMID: 26159879 DOI: 10.1007/s00244-015-0193-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 06/29/2015] [Indexed: 06/04/2023]
Abstract
Mercury (Hg) bioaccumulates in the aquatic food chain in the form of methylmercury, a compound well known for its neurotoxicity. We analyzed total mercury (THg) in hair collected from 209 harbour seals captured at 10 sites in British Columbia (Canada) and Washington State (USA) between 2003 and 2010. In addition, laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) allowed for a highly refined analysis of THg accumulation over time by examining nine whiskers taken from 4- to 6-week-old pups. We estimate that THg concentrations in pups increased sharply at a point corresponding to mid- to late gestation of their time in utero (4.7 ± 0.8 and 6.6 ± 1.3 µg/g dry weight (dw), respectively), and then again at the onset of nursing (8.1 ± 1.3 µg/g dw). These abrupt changes highlight the importance of both pre- and post-natal THg transfer from the mother to the growing fetus and the newborn pup. While THg levels varied among sites, hair analyses from seals collected at the same site demonstrated the influence of age in THg accumulation with pups (5.3 ± 0.3 µg/g) and juveniles (4.5 ± 0.5 µg/g) having lower levels than those in adults (8.3 ± 0.8 µg/g). Our results revealed that 33 % of the pups sampled (n = 167) had THg levels that surpassed a mammalian hair threshold for neurochemical alterations. This study suggests that Hg could represent a health concern to marine wildlife, especially as atmospheric emissions of this toxic element from human activities in the Pacific Rim and worldwide continue.
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Affiliation(s)
- Marie Noël
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, V8W 3P6, Canada
- Ocean Pollution Research Program, Coastal Ocean Research Institute, Vancouver Aquarium Marine Science Center, P.O. Box 3232, Vancouver, BC, V6B 3X8, Canada
| | - Steven Jeffries
- Washington Department of Fish and Wildlife, 7801 Philips Road, Lakewood, WA, 98498, USA
| | - Dyanna M Lambourn
- Washington Department of Fish and Wildlife, 7801 Philips Road, Lakewood, WA, 98498, USA
| | - Kevin Telmer
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC, V8W 3P6, Canada
- Artisanal Gold Council, 101-732 Cormorant St., Victoria, BC, V8W 4A5, Canada
| | - Robie Macdonald
- Institute of Ocean Sciences, Fisheries and Oceans Canada, P.O. Box 6000, Sidney, BC, V8L 4B2, Canada
| | - Peter S Ross
- Ocean Pollution Research Program, Coastal Ocean Research Institute, Vancouver Aquarium Marine Science Center, P.O. Box 3232, Vancouver, BC, V6B 3X8, Canada.
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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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15
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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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16
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Correa L, Rea LD, Bentzen R, O'Hara TM. Assessment of mercury and selenium tissular concentrations and total mercury body burden in 6 Steller sea lion pups from the Aleutian Islands. MARINE POLLUTION BULLETIN 2014; 82:175-182. [PMID: 24661459 PMCID: PMC4123997 DOI: 10.1016/j.marpolbul.2014.02.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/07/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Concentrations of total mercury ([THg]) and selenium ([TSe]) were measured in several tissue compartments in Steller sea lion (Eumetopias jubatus) pups; in addition we determined specific compartment and body burdens of THg. Compartmental and body burdens were calculated by multiplying specific compartment fresh weight by the [THg] (summing compartment burdens equals body burden). In all 6 pup tissue sets (1) highest [THg] was in hair, (2) lowest [THg] was in bone, and (3) pelt, muscle and liver burdens contributed the top three highest percentages of THg body burden. In 5 of 6 pups the Se:Hg molar ratios among compartments ranged from 0.9 to 43.0. The pup with the highest hair [THg] had Se:Hg molar ratios in 9 of 14 compartments that were ⩽ 0.7 potentially indicating an inadequate [TSe] relative to [THg].
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Affiliation(s)
- Lucero Correa
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, PO Box 755940, Fairbanks, AK 99775-5940, USA.
| | - Lorrie D Rea
- Division of Wildlife Conservation, Alaska Department of Fish and Game and Institute of Northern Engineering, Water and Environmental Research Center, University of Alaska Fairbanks, PO Box 755910, Fairbanks, AK 99775-5910, USA
| | - Rebecca Bentzen
- Institute of Arctic Biology and Department of Veterinary Medicine, University of Alaska Fairbanks, PO Box 757000, Fairbanks, AK 99775-5940, USA
| | - Todd M O'Hara
- Institute of Arctic Biology and Department of Veterinary Medicine, University of Alaska Fairbanks, PO Box 757000, Fairbanks, AK 99775-5940, USA
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17
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Rea LD, Castellini JM, Correa L, Fadely BS, O'Hara TM. Maternal Steller sea lion diets elevate fetal mercury concentrations in an area of population decline. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 454-455:277-282. [PMID: 23545490 DOI: 10.1016/j.scitotenv.2013.02.095] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 02/27/2013] [Accepted: 02/27/2013] [Indexed: 06/02/2023]
Abstract
Total mercury concentrations ([THg]) measured in western Aleutian Island Steller sea lion pup hair were the highest maximum [THg] documented in this endangered species to date. Some pups exceeded concentrations at which other fish-eating mammals can exhibit adverse neurological and reproductive effects (21% and 15% pups above 20 and 30 μg/g in hair, respectively). Of particular concern is fetal exposure to mercury during a particularly vulnerable stage of neurological development in late gestation. Hair and blood [THg] were highly correlated and 20% of pups sampled in the western Aleutian Islands of Alaska exceeded mammalian risk thresholds established for each of these tissues. Higher nitrogen isotope ratios suggested that pups accumulated the highest [THg] when their dams fed on higher trophic level prey during late gestation.
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Affiliation(s)
- Lorrie D Rea
- Division of Wildlife Conservation, Alaska Department of Fish and Game, Fairbanks, AK 99701, United States.
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McHuron EA, Harvey JT, Castellini JM, O'Hara TM. Hair sampling location in harbor seals (Phoca vitulina) affects selenium and mercury concentrations: implications for study design of trace element determination in pinnipeds. MARINE POLLUTION BULLETIN 2012; 64:2519-2522. [PMID: 23017952 DOI: 10.1016/j.marpolbul.2012.08.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Revised: 08/20/2012] [Accepted: 08/29/2012] [Indexed: 06/01/2023]
Abstract
Hair is used to determine trace elements exposure and status of pinnipeds because it is an excretory route for many elements and can be collected non-lethally. Despite increased use, there have been few studies on how sampling designs and procedures (e.g., hair type, collection site) affect results. The objective of this study was to determine whether concentrations of an essential (selenium; Se) and non-essential element (mercury; Hg) differed between hair samples collected from two body locations on harbor seals (Phoca vitulina). Concentrations of Se and total Hg (THg) differed between mid-dorsal midline and neck samples, and although the absolute differences were relatively small (Δ(absolute) Se = 0.69 μg g(-1), Δ(absolute) THg = 2.86 μg g(-1)), the relative differences were large (Δ(relative) Se = 49%, Δ(relative) THg = 17%). These differences highlight the need to standardize the collection site for trace element determination in pinnipeds.
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Affiliation(s)
- Elizabeth A McHuron
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA.
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Castellini JM, Rea LD, Lieske CL, Beckmen KB, Fadely BS, Maniscalco JM, O'Hara TM. Mercury concentrations in hair from neonatal and juvenile Steller Sea Lions (Eumetopias jubatus): implications based on age and region in this northern Pacific marine sentinel piscivore. ECOHEALTH 2012; 9:267-277. [PMID: 22815134 DOI: 10.1007/s10393-012-0784-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 06/13/2012] [Accepted: 06/24/2012] [Indexed: 06/01/2023]
Abstract
Mercury is a global contaminant of concern for the fetus and the neonate of piscivores. Methylmercury, produced within marine ecosystems, is of particular concern as a readily absorbed neurotoxicant transported across the blood brain barrier and transplacentally. In the North Pacific Ocean, Steller sea lions are broadly distributed apex predators and, as such, integrate complex food webs and the associated exposure and possible adverse effects of toxic and infectious agents. Hair, including lanugo, was examined using regional and age groupings to assess mercury concentrations in young Alaskan Steller sea lions. The highest concentrations of mercury occurred in the youngest animals, likely via in utero exposure. Based on the adverse developmental outcomes of methylmercury toxicity this specific cohort is of concern. Regionally, higher concentrations of mercury were observed in the endangered western population of Steller sea lions and mirrored patterns observed in human biomonitoring studies of Alaskan coastal communities. These data have broader implications with respect to human and ecosystem health as Steller sea lions rely on similar prey species and foraging areas as those targeted by commercial fisheries and subsistence users and are therefore valuable sentinels of marine ecosystem health.
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Affiliation(s)
- J Margaret Castellini
- Institute of Marine Science, School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK 99775-7220, USA.
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Chen Q, Liu X, Xu L, Sun L, Yan H, Liu Y, Luo Y, Huang J. High levels of methylmercury in guano and ornithogenic coral sand sediments on Xisha islands, South China sea. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2012; 63:177-88. [PMID: 22614866 DOI: 10.1007/s00244-012-9770-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Accepted: 04/16/2012] [Indexed: 05/03/2023]
Abstract
This study determined the distribution and main source of methylmercury in ornithogenic coral sand sediments and pure guano collected from Guangjin and Jinqing islets of the South China Sea. Results showed that the levels of methylmercury (MeHg) and total mercury (THg), as well as the percentage of MeHg relative to THg (%MeHg), are high in both fresh and ancient guano samples. %MeHg in ancient guano exceeded 70 %, much greater than that in fresh seabird droppings (~45 %). These results suggest that excretion through feces likely plays an important role in the cycling of MeHg by seabirds. Guano has been identified as the major source of MeHg in the ornithogenic coral sand sediments in the Xisha Islands. The close relationship between MeHg and guano-derived phosphorus has weakened considerably since 1840 AD. This is probably caused by a significant increase in THg and MeHg in modern guano samples due to the recent increase of Hg pollution. %MeHg in the ornithogenic coral sand sediments is extremely high, ranging from 10 to 30 % (average 20 %).
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Affiliation(s)
- Qianqian Chen
- Institute of Polar Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China
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Lynch M, Kirkwood R, Gray R, Robson D, Burton G, Jones L, Sinclair R, Arnould JPY. Characterization and causal investigations of an alopecia syndrome in Australian fur seals (Arctocephalus pusillus doriferus). J Mammal 2012. [DOI: 10.1644/11-mamm-a-279.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Habran S, Debier C, Crocker DE, Houser DS, Das K. Blood dynamics of mercury and selenium in northern elephant seals during the lactation period. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:2523-2529. [PMID: 21752502 DOI: 10.1016/j.envpol.2011.06.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 06/01/2011] [Accepted: 06/15/2011] [Indexed: 05/31/2023]
Abstract
The effects of reproduction and maternal investment (i.e., milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of mercury (Hg) and selenium (Se) during lactation in the northern elephant seal (Mirounga angustirostris), a top predator from the North Pacific Ocean. Total Hg and Se levels were measured in whole blood and milk of 10 mother-pup pairs on days 5 and 22 of lactation. Both Hg and Se were transferred to offspring through the milk. Results suggested that the maternal transfer of Se was prominent during lactation, whereas the Hg transfer was larger during gestation. The lactation period affected Hg and Se levels in the blood of elephant seal mothers and pups. Physiological processes and their relationship to body condition should be considered carefully when interpreting trace element levels in the framework of biomonitoring.
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Affiliation(s)
- Sarah Habran
- Laboratory for Oceanology - MARE Center B6c, University of Liege, 4000 Liege, Belgium.
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Tan SW, Meiller JC, Mahaffey KR. The endocrine effects of mercury in humans and wildlife. Crit Rev Toxicol 2009; 39:228-69. [DOI: 10.1080/10408440802233259] [Citation(s) in RCA: 206] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Holmes AL, Wise SS, Goertz CEC, Dunn JL, Gulland FMD, Gelatt T, Beckmen KB, Burek K, Atkinson S, Bozza M, Taylor R, Zheng T, Zhang Y, Aboueissa AM, Wise JP. Metal tissue levels in Steller sea lion (Eumetopias jubatus) pups. MARINE POLLUTION BULLETIN 2008; 56:1416-1421. [PMID: 18599091 DOI: 10.1016/j.marpolbul.2008.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Revised: 05/07/2008] [Accepted: 05/12/2008] [Indexed: 05/26/2023]
Abstract
The endangered Western population of the Steller sea lion declined for three decades for uncertain reasons. We present baseline data of metal concentrations in pups as a first step towards investigating the potential threat of developmental exposures to contaminants. Seven metals were investigated: arsenic, cadmium, silver, aluminum, mercury, lead and vanadium. Vanadium was detected in only a single blubber sample. Mercury appears to be the most toxicologically significant metal with concentrations in the liver well above the current action level for mercury in fish. The concentrations of aluminum, arsenic, silver, cadmium and lead were present in one-fourth to two-thirds of all samples and were at either comparable or below concentrations previously reported. Neither gender nor region had a significant effect on metal burdens. Future work should consider metal concentrations in juveniles and adults and toxicological studies need to be performed to begin to assess the toxicity of these metals.
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Affiliation(s)
- Amie L Holmes
- Wise Laboratory of Environmental and Genetic Toxicology, University of Southern Maine, 96 Falmouth Street, Portland, ME 04104, USA
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Yin X, Xia L, Sun L, Luo H, Wang Y. Animal excrement: a potential biomonitor of heavy metal contamination in the marine environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 399:179-185. [PMID: 18466955 DOI: 10.1016/j.scitotenv.2008.03.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 03/04/2008] [Accepted: 03/06/2008] [Indexed: 05/26/2023]
Abstract
To assess the feasibility of using animal excrement to biomonitor the extent of heavy metal contamination in the marine environment, concentrations of mercury (Hg), lead (Pb), copper (Cu) and zinc (Zn) in the fresh excrement of seabirds and marine mammals, along with other biomaterials, from the Arctic, Antarctica (West and East), and Xisha Archipelago of the South China Sea were determined. Results show that the excrement of marine animals at higher trophic levels generally contained high levels of Hg, demonstrating the biomagnification of Hg through food chains in different remote regions. Significant variations in metal accumulation in the excrements were observed among the distinctive geographical areas, with the highest Hg concentration in Xisha Archipelago and the highest Pb concentration in the Arctic, which reflects different levels of air metal pollution at various sampling locations. Concentrations of Cu in the excrements primarily correlate to the geochemical background levels in the regions. High Cu concentrations were found near the Great Wall Station in West Antarctica where a copper mineralized belt exists. No clear spatial variation pattern was found for Zn accumulation in the excrement. This study shows that animal excrement can be used as bioindicators for the level of metal contamination in the marine environment, with the advantages of easy sampling, accurate detection (i.e., with high levels of metal accumulation), and reconstructing historical metal contamination trends by long-term monitoring of sedimentary excrements.
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Affiliation(s)
- Xuebin Yin
- Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026, PR China
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26
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Gray R, Canfield P, Rogers T. Trace element analysis in the serum and hair of Antarctic leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 399:202-215. [PMID: 18486190 DOI: 10.1016/j.scitotenv.2008.03.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 03/25/2008] [Accepted: 03/27/2008] [Indexed: 05/26/2023]
Abstract
Leopard seal, Hydrurga leptonyx, and Weddell seal, Leptonychotes weddellii, occupy an upper trophic level within the Antarctic ecosystem and are useful indicator species in the Southern Ocean of trace element concentrations. Reference values for the concentration of 19 trace elements were determined in the serum and hair of leopard and Weddell seals sampled in Eastern Antarctica. These reference values can be used as 'baseline' levels for monitoring trace element concentrations in these species. Greater trace element concentrations were determined in hair compared to serum, indicating different time scales of trace element accumulation in these samples. For the majority of trace elements, except for Se in the leopard seal samples and Cr in the Weddell seal samples, significant regression relationships for trace element concentrations in hair and serum were not elucidated. Significant differences were determined in the concentrations of seven out of 15 elements with hair type, moult and new, in the leopard seal; concentrations in moult hair were determined to be greater than in new hair for all elements except Zn. Hair analysis was determined to be useful for monitoring exposure to trace elements and when collected off the ice from moulting seals, hair can be employed as a non-invasive sample for trace element analysis in leopard and Weddell seals.
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Affiliation(s)
- Rachael Gray
- Faculty of Veterinary Science, The University of Sydney, NSW 2006 Australia.
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Burger J, Gochfeld M, Jeitner C, Burke S, Stamm T, Snigaroff R, Snigaroff D, Patrick R, Weston J. Mercury levels and potential risk from subsistence foods from the Aleutians. THE SCIENCE OF THE TOTAL ENVIRONMENT 2007; 384:93-105. [PMID: 17590413 DOI: 10.1016/j.scitotenv.2007.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 04/30/2007] [Accepted: 05/04/2007] [Indexed: 05/16/2023]
Abstract
Considerable attention has been devoted to contaminants (mainly PCBs and mercury) in subsistence foods (particularly fish) from various parts of the world. However, relatively little attention has been devoted to examining mercury levels in a full range of subsistence foods from a particular region. While managers and scientists compute risk based on site-specific data on contaminant levels and consumption rates, a first step in making risk decisions by subsistence peoples is knowledge about the relative levels of mercury in the foods they eat. This study examined levels of mercury in subsistence foods (edible components) from several islands in the western Aleutians of Alaska, including algae (4 species), invertebrates (9 species), fish (15 species) and birds (5 species). Samples were gathered by both subsistence hunters/fishers and by scientists using the same equipment. Another objective was to determine if there were differences in mercury levels in subsistence foods gathered from different Aleutian islands. We tested the null hypotheses that there were no interspecific and interisland differences in mercury levels. Because of variation in distribution and the nature of subsistence hunting and fishing, not all organisms were collected from each of the islands. There were significant and important differences in mercury levels among species, but the locational differences were rather small. There was an order of magnitude difference between algae/some invertebrates and fish/birds. Even within fish, there were significant differences. The highest mean mercury levels were in flathead sole (Hippoglossoides elassodon, 0.277 ppm), yellow irish lord (Hemilepidotus jardani, 0.281 ppm), great sculpin (Myoxocephalus polyacanthocephalus, 0.366 ppm), glaucous-winged gull (Larus glaucescens, 0.329 ppm) and its eggs (0.364 ppm), and pigeon guillemot (Cepphus columba, 0.494 ppm). Mercury levels increased with increasing weight of the organisms for limpets (Tectura scutum), and for 11 of the 15 fish species examined. Nine of the 15 fish species had some samples over the 0.3 ppm level, and 7 of 15 fish had some samples over 0.5 ppm. For birds, 95% of the pigeon guillemot muscle samples were above the 0.3 ppm, and 43% were above 0.5 ppm. While health professionals may argue about the risk and benefits of eating fish, and of eating alternative protein sources, the public should be provided with enough information for them to make informed decisions. This is particularly true for subsistence people who consume large quantities of self-caught foods, particularly for sensitive sub-populations, such as pregnant women. We argue that rather than giving people blanket statements about the health benefits or risks from eating fish, information on mean and maximum mercury levels should also be provided on a wide range of subsistence foods, allowing informed decisions, especially by those most at risk.
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Affiliation(s)
- Joanna Burger
- Nelson Biological Laboratory, Division of Life Sciences, Rutgers University, Piscataway, NJ 08854-8082, USA.
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Gerlach SC, Duffy LK, Murray MS, Bowers PM, Adams R, Verbrugge DA. An exploratory study of total mercury levels in archaeological caribou hair from northwest Alaska. CHEMOSPHERE 2006; 65:1909-14. [PMID: 16876850 DOI: 10.1016/j.chemosphere.2006.05.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 05/17/2006] [Accepted: 05/31/2006] [Indexed: 05/11/2023]
Abstract
Over the past ten years, total mercury (THg) levels have been surveyed in Alaskan wildlife and fish as part of the Arctic Monitoring and Assessment (AMAP). Beyond these studies there is little historical data on THg levels in important subsistence species for people in Alaska. A survey of THg in caribou hair from archaeological deposits would provide data to develop temporal trends for this region of the Arctic. Caribou hair from a Western Thule settlement beneath the Alaska native village of Deering (ca. AD 1150) show variability in hair THg values, with a mean level (86 ng/g) which is in the range that is observed in modern Rangifer sp. (caribou and reindeer). Hair from House 1 had a THg mean level of 99.6 ng/g and hair from House 2 had a THg mean of 64.2 ng/g. This is the earliest reported record of mercury in caribou associated with human subsistence activities in the western North American Arctic, and is a first step toward compilation of a needed database through which to measure and evaluate exposure to mercury by people who rely heavily on caribou as a food source. We hypothesize that similarity in mercury values in archaeological samples of caribou and in contemporary samples would give an additional perspective on human exposure to mercury through caribou harvest and consumption today. Since this hypothesis will be more useful if evaluated at a regional rather than global scale, further studies will be needed at different archaeological sites across Alaska to determine the generality of this observation in relation to geographic scale.
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Affiliation(s)
- S Craig Gerlach
- Department of Anthropology, 310 Eielson, P.O. Box 757720, University of Alaska Fairbanks, Fairbanks, AK 99775-7720, USA
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Sun L, Yin X, Liu X, Zhu R, Xie Z, Wang Y. A 2,000-year record of mercury and ancient civilizations in seal hairs from King George Island, West Antarctica. THE SCIENCE OF THE TOTAL ENVIRONMENT 2006; 368:236-47. [PMID: 16297967 DOI: 10.1016/j.scitotenv.2005.09.092] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2005] [Revised: 06/25/2005] [Accepted: 09/26/2005] [Indexed: 05/05/2023]
Abstract
The concentrations of total mercury (Hg(T)) and three bio-essential elements (phosphor, potassium, sodium) were analyzed in Antarctic seal hairs from a lake core spanning the past 2,000 years and collected from King George Island (63 degrees 23'S, 57 degrees 00'W), West Antarctica. The Hg(T) concentration shows a significant fluctuation while the levels of the three bio-essential elements remain almost constant. The rise and fall of the Hg(T) concentration in the seal hairs are found to be closely coincided with ancient activities of gold and silver mining using Hg-amalgamation process around the world, especially in the Southern Hemisphere. Briefly, Hg(T) levels are high during five episodes of extensive gold and silver mining activities--Rome Empire and China Han Dynasty (approximately 18-300 A.D.), Maya period and China Tang (750-900 A.D.), Incas civilization and Christian Kingdom (1200-1500 A.D.), New world (1650-1800 A.D.), and modern industry period (1840 A.D.-present); they are low during four time periods of reduced gold and silver mining activities--the China Han and Rome fall (since 300 A.D.), Maya fall and Wartime period in China (1050-1250 A.D.), Pizarro coming (ca. 1532 A.D.) and Independence War of South America (1800-1830 A.D.). Two profiles of Hg(T) in other two lake cores, one affected by seal excrements and the other by penguin droppings, from the same region are similar to the one in seal hairs. The Hg concentration profile in the seal hairs is significantly correlated with the one in a peat bog of Southern Chile near King George Island. Since Hg is existent mainly at the form of methyl-mercury in seal hairs, this correlation supports a relationship and link between atmospheric mercury concentration and methyl-mercury production. Comparing with samples from American and European continents, the Antarctic seal hairs provide an archive of total mercury concentration in surface seawater of the South Ocean less affected by regional human activities, and this archive may provide a good reference for assessing the global Hg emissions, depositions and recycling in the past thousand years.
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MESH Headings
- Animals
- Antarctic Regions
- Environmental Monitoring
- Feces
- Geologic Sediments
- Hair/chemistry
- History, 15th Century
- History, 16th Century
- History, 17th Century
- History, 18th Century
- History, 19th Century
- History, 20th Century
- History, 21st Century
- History, Ancient
- History, Medieval
- Mercury/analysis
- Mercury/history
- Seals, Earless
- Water Pollutants, Chemical/analysis
- Water Pollutants, Chemical/history
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Affiliation(s)
- Liguang Sun
- Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
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Rothschild RFN, Duffy LK. Mercury concentrations in muscle, brain and bone of Western Alaskan waterfowl. THE SCIENCE OF THE TOTAL ENVIRONMENT 2005; 349:277-83. [PMID: 16076480 DOI: 10.1016/j.scitotenv.2005.05.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 05/25/2005] [Indexed: 05/03/2023]
Abstract
Total mercury (THg), which includes both inorganic (Hg(2+)) and methylmercury (MeHg) species, has been reported for seabirds in the North Pacific and Alaska. For the Yup'ik and Aleut people of Alaska, waterfowl are a small but important seasonal component of the diet, but many Alaskan species have not been studied extensively for the presence of mercury. Birds are good subjects for examination of mercury concentrations because they feed at different trophic levels, they can be long-lived, and many are both abundant and widely distributed. In this study, we present the levels of mercury in muscle, brain, and bone tissue of 140 birds taken by subsistence food users across Western Alaska. THg wet weight mean concentrations in the 18 species of waterfowl surveyed ranged from 0.8 to 268.6 ng/g in muscle, from 0.4 to 197.7 ng/g in brain and from 0.7 to 422.9 ng/g in bone. The null hypothesis that there are no interspecific differences in the level of total mercury in the 18 species of Alaska birds surveyed was not supported. We found interspecific differences with the Lesser Scaup (Aythya affinis), and the Black Scoter (Melanitta nigra), having the highest muscle tissue levels of THg. In general, THg mean levels were higher in muscle than in brain with the exceptions of the Bar-tailed Godwit and Northern Shoveler. Bone THg were highest in the Black Scoter. The mean values for THg in the species studied are unlikely to cause adverse reproductive or behavioral effects in the birds.
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Affiliation(s)
- Roger F N Rothschild
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, 99775-6160, USA
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Duffy LK, Duffy RS, Finstad G, Gerlach C. A note on mercury levels in the hair of Alaskan reindeer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2005; 339:273-276. [PMID: 15740775 DOI: 10.1016/j.scitotenv.2004.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Accepted: 12/01/2004] [Indexed: 05/24/2023]
Abstract
Reindeer, as terrestrial herbivores, generally have low levels of Hg, but monitoring Hg levels can help in understanding ecological toxicity related to a changing environment. In this study, Alaskan reindeer were analyzed for total mercury (THg) in their hair. Both free-ranging reindeer from the Seward Peninsula, Alaska and reindeer fed a pollock-based fishmeal diet were surveyed. Free ranging reindeer had mean THg levels of (55.3 ng/g; n=5). The mean MeHg level in the free ranging reindeer was 45.5 (ng/g; n=5) or 79% of the THg level. The mean level for THg in the fishmeal fed reindeer was 19 ng/g (n=10). Younger reindeer (2 years of age or less) showed lower levels (0.8 ng/g, n=2) compared to adult reindeer (30.8 ng/g, n=6).
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Affiliation(s)
- Lawrence K Duffy
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Box 756160, Fairbanks, AK 99775-6160, USA.
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Barron MG, Heintz R, Krahn MM. Contaminant exposure and effects in pinnipeds: implications for Steller sea lion declines in Alaska. THE SCIENCE OF THE TOTAL ENVIRONMENT 2003; 311:111-133. [PMID: 12826388 DOI: 10.1016/s0048-9697(03)00140-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
After nearly 3 decades of decline, the western stock of Steller sea lions (SSL; Eumetopias jubatus) was listed as an endangered species in 1997. While the cause of the decline in the 1970s and 1980s has been attributed to nutritional stress, recent declines are unexplained and may result from other factors including the presence of environmental contaminants. SSL tissues show accumulation of butyltins, mercury, PCBs, DDTs, chlordanes and hexachlorobenzene. SSL habitats and prey are contaminated with additional chemicals including mirex, endrin, dieldrin, hexachlorocyclohexanes, tetrachlorodibenzo-p-dioxin (TCDD) and related compounds, cadmium and lead. In addition, many SSL haulouts and rookeries are located near other hazards including radioactivity, solvents, ordnance and chemical weapon dumps. PCB and DDT concentrations measured in a few SSL during the 1980s were the highest recorded for any Alaskan pinniped. Some contaminant exposures in SSL appear to be elevated in the Gulf of Alaska and Bering Sea compared to southeast Alaska, but there are insufficient data to evaluate geospatial relationships with any certainty. Based on very limited blubber data, current levels of PCBs may not pose a risk to SSL based on comparison to immunotoxicity tissue benchmarks, but SSL may have been at risk from pre-1990 PCB exposures. While exposure to PCBs and DDTs may be declining, SSL are likely exposed to a multitude of other contaminants that have not been monitored. The impacts of these exposures on SSL remain unknown because causal effects have not been established. Field studies with SSL have been limited in scope and have not yet linked contaminant exposures to adverse animal health or population effects. Several biomarkers may prove useful for monitoring exposure and additional research is needed to evaluate their utility in SSL. We conclude that there are insufficient data to reject the hypothesis that contaminants play a role in the continued decline of SSL, and suggest that a coordinated monitoring program be developed which can be related to key biological, ecological and laboratory toxicity data.
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Affiliation(s)
- Mace G Barron
- P.E.A.K. Research, 1134 Avon Lane, Longmont, CO 80501, USA.
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