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Segner H, Bailey C, Tafalla C, Bo J. Immunotoxicity of Xenobiotics in Fish: A Role for the Aryl Hydrocarbon Receptor (AhR)? Int J Mol Sci 2021; 22:ijms22179460. [PMID: 34502366 PMCID: PMC8430475 DOI: 10.3390/ijms22179460] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 02/07/2023] Open
Abstract
The impact of anthropogenic contaminants on the immune system of fishes is an issue of growing concern. An important xenobiotic receptor that mediates effects of chemicals, such as halogenated aromatic hydrocarbons (HAHs) and polyaromatic hydrocarbons (PAHs), is the aryl hydrocarbon receptor (AhR). Fish toxicological research has focused on the role of this receptor in xenobiotic biotransformation as well as in causing developmental, cardiac, and reproductive toxicity. However, biomedical research has unraveled an important physiological role of the AhR in the immune system, what suggests that this receptor could be involved in immunotoxic effects of environmental contaminants. The aims of the present review are to critically discuss the available knowledge on (i) the expression and possible function of the AhR in the immune systems of teleost fishes; and (ii) the impact of AhR-activating xenobiotics on the immune systems of fish at the levels of immune gene expression, immune cell proliferation and immune cell function, immune pathology, and resistance to infectious disease. The existing information indicates that the AhR is expressed in the fish immune system, but currently, we have little understanding of its physiological role. Exposure to AhR-activating contaminants results in the modulation of numerous immune structural and functional parameters of fish. Despite the diversity of fish species studied and the experimental conditions investigated, the published findings rather uniformly point to immunosuppressive actions of xenobiotic AhR ligands in fish. These effects are often associated with increased disease susceptibility. The fact that fish populations from HAH- and PAH-contaminated environments suffer immune disturbances and elevated disease susceptibility highlights that the immunotoxic effects of AhR-activating xenobiotics bear environmental relevance.
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Affiliation(s)
- Helmut Segner
- Centre for Fish and Wildlife Health, Department of Pathobiology and Infectious Diseases, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | | | | | - Jun Bo
- Laboratory of Marine Biology and Ecology, Third Institute of Oceanography, Xiamen 361005, China
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Subacute cadmium exposure promotes M1 macrophage polarization through oxidative stress-evoked inflammatory response and induces porcine adrenal fibrosis. Toxicology 2021; 461:152899. [PMID: 34416349 DOI: 10.1016/j.tox.2021.152899] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/26/2021] [Accepted: 08/13/2021] [Indexed: 12/17/2022]
Abstract
Cadmium (Cd) is a widely distributed environmental pollutant with immunotoxicity and endocrine toxicity. M1/M2 macrophages participate in the immune response and exert an essential influence on fibrosis. Nevertheless, whether Cd can induce porcineadrenal fibrosis by affecting the polarization of M1/M2 macrophages and its potential regulatory mechanism have not been explored. We added 20 mg/kg CdCl2 to the pig diet for 40 days to investigate the fibrogenic effect of subacute Cd exposure on the adrenal gland. The results indicated that the ACTH and CORT in serum were decreased by 15.26 % and 21.99 %, respectively. The contents of adrenal mineral elements Cd, Cr, Mn were increased up to 34, 1.93, 1.42 folds and Co, Zn, Sn were reduced by 21.57 %, 20.52 %, 15.75 %. Concurrently, the pro-oxidative indicators (LPO, MDA and H2O2) were increased by 1.85, 2.20, 2.77 folds and 3.60, 11.15, 4.11 folds upregulated mRNA levels of TLR4, NF-κB, NLRP3 were observed. Subsequently, the expression of M1 macrophages polarization markers (IL-6, iNOS, TNF-α, CCL2 and CXCL9) were raised by 2.03, 2.30, 2.35, 1.58, 1.56 folds, while M2 macrophages (IL-4, CCL24, Arg1, IL-10, MRC1) showed a 62.34 %, 31.88 %, 50.26 %, 74.00 %, 69.34 % downregulation. The expression levels of AMPK subunits and genes related to glycolysis, oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) were also markedly increased. Additionally, the expression level of TGF-β1, Smad2/3 and downstream pro-fibrotic markers was obviously upregulated. Taken together, we conclude that Cd activates the oxidative stress-mediated TLR4/NF-κB/NLRP3 inflammatory signal transduction, leading to porcine adrenal fibrosis by promoting macrophage polarization toward M1.
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Lèche A, Gismondi E, Martella MB, Navarro JL. First assessment of persistent organic pollutants in the Greater rhea (Rhea americana), a near-threatened flightless herbivorous bird of the Pampas grasslands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:27681-27693. [PMID: 33515150 DOI: 10.1007/s11356-021-12614-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/18/2021] [Indexed: 06/12/2023]
Abstract
Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the occurrence of these contaminants in terrestrial birds from South America. In this study, POPs were assessed for the first time in a flightless herbivorous species from the Pampas grasslands, the Greater rhea (Rhea americana). Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) were determined in 18 samples of feathers from free-ranging and captive individuals inhabiting four sites with different land uses in central Argentina. Among the 16 POPs tested in those feathers, 6 PCBs (28, 52, 101, 138, 153, and 180) and 8 OCPs (α-HCH, β-HCH, γ-HCH, p,p'-DDE, p,p'-DDD, o,p'-DDT, p,p'-DDT, and HCB) were quantified. No PBDEs were detected. The total concentration of POPs was higher in populations living in an intensive crop production area (agriculture 159 ng g -1 and farm: 97.53 ng g-1) compared with the population in an urban area (zoo 45.86 ng g-1) and an agroecosystem with extensive rearing of livestock (cattle rearing 36.77 ng g-1). PCBs were the most abundant pollutants in all the populations studied. Lower chlorinated CB 52 and CB 101 were the principal PCB congeners detected, representing at least 70% of the total quantified. All populations studied showed a DDE + DDD/DDT ratio > 1, indicating a historical application of this insecticide. This study provides a new contribution to the scarce data on POP concentrations in South American bird species. Further investigations are needed to evaluate their potential effects on the health of individuals and populations.
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Affiliation(s)
- Alvina Lèche
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000, Córdoba, Argentina.
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Rondeau 798, 5000, Cordoba, CP, Argentina.
| | - Eric Gismondi
- Laboratory of Animal Ecology and Ecotoxicology (LEAE) - Freshwater and OceaniC sciences Unit of reSearch (FOCUS), Chemistry Institute, University of Liège, Bât. B6C, 11 allée du 6 Août, B-4000 Sart-Tilman, Liège, Belgium
| | - Mónica B Martella
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Rondeau 798, 5000, Cordoba, CP, Argentina
| | - Joaquín L Navarro
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Centro de Zoología Aplicada, Rondeau 798, CP 5000, Córdoba, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Diversidad y Ecología Animal (IDEA), Rondeau 798, 5000, Cordoba, CP, Argentina
- Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecología, Cátedra de Problemática Ambiental, Cordoba, Argentina
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Owen K, Sköld M, Carlström J. An increase in detection rates of the critically endangered Baltic Proper harbor porpoise in Swedish waters in recent years. CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Kylie Owen
- Department of Environmental Research and Monitoring Swedish Museum of Natural History Stockholm Sweden
| | - Martin Sköld
- Department of Environmental Research and Monitoring Swedish Museum of Natural History Stockholm Sweden
- Department of Mathematics Stockholm University Stockholm Sweden
| | - Julia Carlström
- Department of Environmental Research and Monitoring Swedish Museum of Natural History Stockholm Sweden
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Dietz R, Sonne C, Jenssen BM, Das K, de Wit CA, Harding KC, Siebert U, Olsen MT. The Baltic Sea: An ecosystem with multiple stressors. ENVIRONMENT INTERNATIONAL 2021; 147:106324. [PMID: 33326905 DOI: 10.1016/j.envint.2020.106324] [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: 11/24/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 06/12/2023]
Abstract
This introductory chapter to our Environment International VSI does not need an abstract and therefore we just include our recommendations below in order to proceed with the resubmission. Future work should examine waterbirds as food web sentinels of multiple stressors as well as Baltic Sea food web dynamics of hazardous substances and how climate change may modify it. Also, future work should aim at further extending the new frameworks developed within BALTHEALTH for energy and contaminant transfer at the population level (Desforges et al., 2018, Cervin et al., 2020/this issue Silva et al., 2020/this issue) and their long term effects on Baltic Sea top predators, such as harbour porpoises, grey seals ringed seals, and white-tailed eagles. Likewise, the risk evaluation conducted for PCB in connection with mercury on Arctic wildlife (Dietz et al., 2019, not a BONUS BALTHEALTH product) could be planned for Baltic Sea molluscs, fish, bird and marine mammals in the future. Finally, future efforts could include stressors not covered by the BONUS BALTHEALTH project, such as food web fluxes, overexploitation, bycatches, eutrophication and underwater noise.
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Affiliation(s)
- R Dietz
- Department of Bioscience, Arctic Research Centre (ARC), Aarhus University, Faculty of Science and Technology, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark.
| | - C Sonne
- Department of Bioscience, Arctic Research Centre (ARC), Aarhus University, Faculty of Science and Technology, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - B M Jenssen
- Department of Bioscience, Arctic Research Centre (ARC), Aarhus University, Faculty of Science and Technology, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark; Department of Biology, Norwegian University of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway
| | - K Das
- Freshwater and Oceanic sciences Unit of reSearch (FOCUS), Laboratory of Oceanology, University of Liege, Allée du six Août 11, Bât. B6C, 4000 Liège, Belgium
| | - C A de Wit
- Department of Environmental Science, Stockholm University, Svante Arrheniusvägen 8, SE-10691 Stockholm, Sweden
| | - K C Harding
- Department of Biological and Environmental Sciences, Gothenburg University, Box 461, SE-40530 Gothenburg, Sweden
| | - U Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Büsum, Germany
| | - M T Olsen
- Evolutionary Genomics, Globe Institute, University of Copenhagen, Øster Farimagsgade 5, DK-1353 Copenhagen K, Denmark
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Hoondert RPJ, Ragas AMJ, Hendriks AJ. Simulating changes in polar bear subpopulation growth rate due to legacy persistent organic pollutants - Temporal and spatial trends. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142380. [PMID: 33254886 DOI: 10.1016/j.scitotenv.2020.142380] [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: 05/26/2020] [Revised: 08/18/2020] [Accepted: 09/11/2020] [Indexed: 06/12/2023]
Abstract
Although atmospheric concentrations of many conventional persistent organic pollutants (POPs) have decreased in the Arctic over the past few decades, levels of most POPs and mercury remain high since the 1990s or start to increase again in Arctic areas, especially polar bears. So far, studies generally focused on individual effects of POPs, and do not directly link POP concentrations in prey species to population-specific parameters. In this study we therefore aimed to estimate the effect of legacy POPs and mercury on population growth rate of nineteen polar bear subpopulations. We modelled population development in three scenarios, based on species sensitivity distributions (SSDs) derived for POPs based on ecotoxicity data for endothermic species. In the first scenario, ecotoxicity data for polar bears were based on the HC50 (the concentration at which 50% of the species is affected). The other two scenarios were based on the HC5 and HC95. Considerable variation in effects of POPs could be observed among the scenarios. In our intermediate scenario, we predicted subpopulation decline for ten out of 15 polar bear subpopulations. The estimated population growth rate was least reduced in Gulf of Boothia and Foxe Basin. On average, PCB concentrations in prey (in μg/g toxic equivalency (TEQ)) posed the largest threat to polar bear subpopulations, with negative modelled population growth rates for the majority of subpopulations. We did not find a correlation between modelled population changes and monitored population trends for the majority of chemical-subpopulation combinations. Modelled population growth rates increased over time, implying a decreasing effect of PCBs, DDTs, and mercury. Polar bear subpopulations are reportedly still declining in four out of the seven subpopulations for which sufficient long-term monitoring data is available, as reported by the IUCN-PBSG. This implies that other emerging pollutants or other anthropogenic stressors may affect polar bear subpopulations.
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Affiliation(s)
- Renske P J Hoondert
- Department of Environmental Science, Institute for Wetland and Water Research, Faculty of Science, Radboud University Nijmegen, the Netherlands.
| | - Ad M J Ragas
- Department of Environmental Science, Institute for Wetland and Water Research, Faculty of Science, Radboud University Nijmegen, the Netherlands; Faculty of Management, Science and Technology, Open University, the Netherlands
| | - A Jan Hendriks
- Department of Environmental Science, Institute for Wetland and Water Research, Faculty of Science, Radboud University Nijmegen, the Netherlands
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Silva WTAF, Bottagisio E, Härkönen T, Galatius A, Olsen MT, Harding KC. Risk for overexploiting a seemingly stable seal population: influence of multiple stressors and hunting. Ecosphere 2021. [DOI: 10.1002/ecs2.3343] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Willian T. A. F. Silva
- Department of Biology and Environmental Sciences University of Gothenburg Gothenburg Sweden
| | - Elio Bottagisio
- Department of Biology and Environmental Sciences University of Gothenburg Gothenburg Sweden
| | | | - Anders Galatius
- Section for Marine Mammal Research Department of Bioscience Aarhus University Frederiksborgvej 399 Roskilde4000Denmark
| | - Morten Tange Olsen
- Section for Evolutionary Genomics Globe Institute University of Copenhagen Copenhagen Denmark
| | - Karin C. Harding
- Department of Biology and Environmental Sciences University of Gothenburg Gothenburg Sweden
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Schmidt B, Sonne C, Nachtsheim D, Wohlsein P, Persson S, Dietz R, Siebert U. Liver histopathology of Baltic grey seals (Halichoerus grypus) over three decades. ENVIRONMENT INTERNATIONAL 2020; 145:106110. [PMID: 32937284 DOI: 10.1016/j.envint.2020.106110] [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: 01/24/2020] [Revised: 08/31/2020] [Accepted: 08/31/2020] [Indexed: 06/11/2023]
Abstract
The liver plays an important role in the metabolism and elimination of endogenic and exogenic lipid-soluble compounds. Multiple studies have shown that polychlorinated biphenyls (PCB) and dichlorodiphenyl trichloroethane (DDT) lead to morphological changes in liver cells. The aim of the present study was therefore to analyse liver changes over time in Baltic grey seals (Halichoerus grypus) and to correlate these with historical PCB and DDT contaminations. A total of 191 liver samples were collected between 1981 and 2015 in the Gulf of Bothnia and northern Baltic Proper. Six histological features were evaluated, including portal mononuclear cell infiltration, random mononuclear cell infiltration, lipid granulomas, hepatocellular fat vacuoles, hepatic stellate cells and mild multifocal bile duct hyperplasia accompanied by portal fibrosis. Three of the six lesions showed a significant correlation with age. Furthermore, a positive correlation between portal mononuclear cell infiltration and mild multifocal bile duct hyperplasia was found. Additionally, lipid granulomas were significantly correlated with hepatic stellate cells. More importantly, hepatic stellate cells and mild multifocal bile duct hyperplasia were correlated with adipose tissue (blubber) concentrations of ƩPCB, measured in a subsample (n = 34) of all individuals. No correlation with lesions and ƩDDT concentrations were found. These results show that age is an important factor for the development of these liver lesions, but PCBs burden may be an influencing factor. This is in agreement with previous studies of marine mammals in the Baltic Sea as well as in the Arctic. We therefore conclude that not only age of the animals, but also exposure to PCBs should be taken into account when understanding and evaluating the current health status of Baltic grey seals.
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Affiliation(s)
- Britta Schmidt
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, D-25761 Büsum, Germany
| | - Christian Sonne
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Dominik Nachtsheim
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, D-25761 Büsum, Germany
| | - Peter Wohlsein
- Department of Pathology, University of Veterinary Medicine, Bünteweg 17, D-30559 Hannover, Germany
| | - Sara Persson
- Department of Environmental Research and Monitoring, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05 Stockholm, Sweden
| | - Rune Dietz
- Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde, Denmark
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Werftstraße 6, D-25761 Büsum, Germany; Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, P.O. Box 358, DK-4000 Roskilde, Denmark.
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Cervin L, Harkonen T, Harding KC. Multiple stressors and data deficient populations; a comparative life-history approach sheds new light on the extinction risk of the highly vulnerable Baltic harbour porpoises (Phocoena phocoena). ENVIRONMENT INTERNATIONAL 2020; 144:106076. [PMID: 32891921 DOI: 10.1016/j.envint.2020.106076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 05/21/2023]
Abstract
Many endangered marine mammal populations are difficult to study, spread out over large areas, and capturing them for branding and research purposes would be unethical. Yet, they are in urgent need for assessment and conservation actions. We suggest collecting data from other more abundant populations of the same species, with careful consideration of body size, age at sexual maturity, and ecological conditions to produce scientifically sound best approximations of vital rates of data deficient endangered populations. The genetically distinct Baltic Sea harbour porpoise population amounts to about 500 animals and is classified as 'Critically Endangered' according to the IUCN red list. Data deficiency on nearly all demographic parameters have precluded systematic investigations of the relative importance of stressors affecting population viability. We took a comparative life history approach and investigated the phenotypic plasticity in somatic and demographic vital rates of seven larger, well studied North Atlantic harbour porpoise populations, enabling us to approximate the missing pieces of the life history of the Baltic population. We parameterized a stochastic, individual-based population model, and performed a population viability analysis for a range of biologically realistic parameter values and scenarios of environmental stressors. The baseline scenario was based on the most representative samples of healthy harbour porpoise populations and challenged with three different levels of bycatches. Due to high levels of endocrine disruptive contaminants observed in Baltic harbour porpoises, we also investigated the effect of a possible reduction in fecundity. Subsequently, the combined effects of bycatches and reduced fecundity were investigated in terms of population growth rate and quasi-extinction risk. The Baltic harbour porpoise population is viable in the baseline scenario without anthropogenic stressors. However, even the lowest estimated bycatch level of 7 individuals per year will lead to a population collapse to ≤50 animals with high probability (0.4-1.0) over the next century, assuming an intermediate or low (<73%) fecundity. Adult survival is of critical importance and mitigation of fishery impacts and reduction of anthropogenic disturbances in the identified main breeding areas are recommended.
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Affiliation(s)
- Linnea Cervin
- Department of Biological and Environmental Sciences, Gothenburg University, Box 461, S-40530 Gothenburg, Sweden
| | | | - Karin C Harding
- Department of Biological and Environmental Sciences, Gothenburg University, Box 461, S-40530 Gothenburg, Sweden.
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Seguel M, George RC, Maboni G, Sanchez S, Page-Karjian A, Wirth E, McFee W, Gottdenker NL. Pathologic findings and causes of death in bottlenose dolphins Tursiops truncatus stranded along the Georgia coast, USA (2007-2013). DISEASES OF AQUATIC ORGANISMS 2020; 141:25-38. [PMID: 32940248 DOI: 10.3354/dao03509] [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] [Indexed: 06/11/2023]
Abstract
Between 2007 and 2013, before the 2013 cetacean morbillivirus outbreak, 26 fresh bottlenose dolphin carcasses were necropsied on the coast of Georgia, USA. Here, we present the pathological and microbiological findings associated with their most likely causes of death. The primary cause of death was determined in 25 individuals and included systemic bacterial infection (n = 7), verminous and bacterial bronchopneumonia (n = 5), drowning/entanglement (n = 5), disseminated histoplasmosis (n = 1), intestinal intussusception (n = 1), vegetative endocarditis (n = 1), meningitis (n = 1), necrotizing dermatitis (n = 1), disseminated angiomatosis (n = 1), emaciation (n = 1) and stingray spine trauma (n = 1). Histiocytic and eosinophilic bronchopneumonia associated with Halocerchus sp. infection was observed in 69% of the animals (18/26) and eosinophilic gastritis due to Anisakidae nematodes was found in 36% of the examined stomachs (8/22). Moderate to severe eosinophilic pancreatitis with fibrosis was observed in 4 animals infected with Brachycladiidae trematodes. Proliferative and ulcerative lymphoplasmacytic dermatitis was found in 5 animals and was considered to contribute to deteriorated health status in 2 calves. Pulmonary and lymph node angiomatosis were observed in 15 and 10 animals, respectively. In at least 2 animals, the concentration of polychlorinated biphenyls (PCBs) in the blubber exceeded 1500 µg g-1 of lipid. Bottlenose dolphins stranded on the Georgia coast have a wide range of inflammatory lesions associated with a variety of helminth, bacterial, and fungal pathogens. Some resident animals have also been exposed to high levels of PCB contamination, which could reduce host immunocompetence. Higher exposure to these or other pathogens could result in further decline in the health of resident and migrant dolphin populations in this region.
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Affiliation(s)
- M Seguel
- Department of Pathology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602, USA
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