| 1. |
- Lehnert, Kristina, et al.
(author)
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Cytokine expression and lymphocyte proliferative capacity in diseased harbor porpoises (Phocoena phocoena) - Biomarkers for health assessment in wildlife cetaceans
- 2019
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In: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 247, s. 783-791
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Journal article (peer-reviewed)abstract
- Harbor porpoises (Phocoena phocoena) in the North and Baltic Seas are exposed to anthropogenic influences including acoustic stress and environmental contaminants. In order to evaluate immune responses in healthy and diseased harbor porpoise cells, cytokine expression analyses and lymphocyte proliferation assays, together with toxicological analyses were performed in stranded and bycaught animals as well as in animals kept in permanent human care. Severely diseased harbor porpoises showed a reduced proliferative capacity of peripheral blood lymphocytes together with diminished transcription of transforming growth factor-beta and tumor necrosis factor-alpha compared to healthy controls. Toxicological analyses revealed accumulation of polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyltrichloroethane (DDT) in harbor porpoise blood samples. Correlation analyses between blood organochlorine levels and immune parameters revealed no direct effects of xenobiotics upon lymphocyte proliferation or cytokine transcription, respectively. Results reveal an impaired function of peripheral blood leukocytes in severely diseased harbor porpoises, indicating immune exhaustion and increased disease susceptibility.
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| 2. |
- Boyi, Joy Ometere, et al.
(author)
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Relationships between gene transcription and contaminant concentrations in Baltic ringed seals : A comparison between tissue matrices
- 2022
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In: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 242
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Journal article (peer-reviewed)abstract
- Ringed seals (Pusa hispida) are slowly recovering in the eastern and northern parts of the Baltic Sea after years of hunting pressure and contaminant exposure. Still, consequences of anthropogenic activities such as contaminant exposure and increasing temperatures are stressors that continue to have deleterious effects on their habitat and health. Transcription profiles of seven health-related genes involved in xenobiotic metabolism, endocrine disruption and stress were evaluated in blood, blubber, and liver of Baltic ringed seals in a multi-tissue approach. Selected persistent organic pollutants and total mercury concentrations were measured in blubber and liver, and muscle and liver of these animals, respectively. Concentrations of contaminants varied across tissues on a lipid weight basis but not with sex. mRNA transcript levels for all seven target genes did not vary between sexes or age classes. Transcript levels of thyroid hormone receptor alpha (TR alpha), retinoic acid receptor alpha (RAR alpha) and heat shock protein 70 (HSP70) correlated with levels of persistent organic pollutants. TR alpha transcript levels also correlated positively with mercury concentrations in the liver. Of the three tissues assessed in this multi-tissue approach, blubber showed highest transcription levels of aryl hydrocarbon receptor nuclear translocator (ARNT), thyroid stimulating hormone receptor beta (TSH beta), oestrogen receptor alpha (ESR1) and peroxisome proliferator activated receptor alpha (PPAR alpha). The wide range of genes expressed highlights the value of minimally invasive sampling (e.g. biopsies) for assessing health endpoints in free-ranging marine wildlife and the importance of identifying optimal matrices for targeted gene expression studies. This gene transcript profile study has provided baseline information on transcript levels of biomarkers for early on-set health effects in ringed seals and will be a useful guide to assess the impacts of environmental change in Baltic pinnipeds for conservation and management.
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| 3. |
- Hammond, Philip S., et al.
(author)
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Cetacean abundance and distribution in European Atlantic shelf waters to inform conservation and management
- 2013
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In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 164, s. 107-122
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Journal article (peer-reviewed)abstract
- The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we surveyed the entire EU Atlantic continental shelf to generate robust estimates of abundance for harbour porpoise and other cetacean species. The survey used line transect sampling methods and purpose built data collection equipment designed to minimise bias in estimates of abundance. Shipboard transects covered 19,725 km in sea conditions <= Beaufort 4 in an area of 1,005,743 km(2). Aerial transects covered 15,802 km in good/moderate conditions (<= Beaufort 3) in an area of 364,371 km(2). Thirteen cetacean species were recorded; abundance was estimated for harbour porpoise (375,358; CV = 0.197), bottlenose dolphin (16,485; CV = 0.422), white-beaked dolphin (16,536; CV = 0.303), short-beaked common dolphin (56,221; CV = 0.234) and minke whale (18,958; CV = 0.347). Abundance in 2005 was similar to that estimated in July 1994 for harbour porpoise, white-beaked dolphin and minke whale in a comparable area. However, model-based density surfaces showed a marked difference in harbour porpoise distribution between 1994 and 2005. Our results allow EU Member States to discharge their responsibilities under the Habitats Directive and inform other international organisations concerning the assessment of conservation status of cetaceans and the impact of bycatch at a large spatial scale. The lack of evidence for a change in harbour porpoise abundance in EU waters as a whole does not exclude the possibility of an impact of bycatch in some areas. Monitoring bycatch and estimation of abundance continue to be essential. (C) 2013 The Authors.
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| 4. |
- Sonne, Christian, et al.
(author)
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A review of pathogens in selected Baltic Sea indicator species
- 2020
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In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750.
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Research review (peer-reviewed)abstract
- Here we review the state-of-the-art of pathogens in select marine and terrestrial key species of the Baltic Sea, i.e.ringed seal (Pusa hispida), harbour seal (Phoca vitulina), grey seal (Halichoerus grypus), harbour porpoise(Phocoena phocoena), common eider (Somateria mollissima), pink-footed goose (Anser brachyrhynchus) and whitetailedeagle (Haliaeetus albicilla). This review is the first to merge and present available information and baselinedata for the FP7 BONUS BaltHealth project: Baltic Sea multilevel health impacts on key species of anthropogenichazardous substances. Understanding the spread, prevalence and effects of wildlife pathogens is important for theunderstanding of animal and ecosystem health, ecosystem function and services, as well as human exposure tozoonotic diseases. This review summarises the occurrence of parasites, viruses and bacteria over the past sixdecades, including severe outbreaks of Phocine Distemper Virus (PDV), the seroprevalence of Influenza A andthe recent increase in seal parasites. We show that Baltic high trophic key species are exposed to multiplebacterial, viral and parasitic diseases. Parasites, such as C. semerme and P. truncatum present in the colon andliver Baltic grey seals, respectively, and anisakid nematodes require particular monitoring due to their effects onanimal health. In addition, distribution of existing viral and bacterial pathogens, along with the emergence andspread of new pathogens, need to be monitored in order to assess the health status of key Baltic species. Relevantbacteria are Streptococcus spp., Brucella spp., Erysipelothrix rhusiopathiae, Mycoplasma spp. and Leptospira interrogans;relevant viruses are influenza virus, distemper virus, pox virus and herpes virus. This is of special importanceas some of the occurring pathogens are zoonotic and thus also pose a potential risk for human health.Marine mammal handlers, as well as civilians that by chance encounter marine mammals, need to be aware ofthis risk. It is therefore important to continue the monitoring of diseases affecting key Baltic species in order toassess their relationship to population dynamics and their potential threat to humans. These infectious agents arevaluable indicators of host ecology and can act as bioindicators of distribution, migration, diet and behaviour ofmarine mammals and birds, as well as of climate change and changes in food web dynamics. In addition, infectiousdiseases are linked to pollutant exposure, overexploitation, immune suppression and subsequent inflammatorydisease. Ultimately, these diseases affect the health of the entire ecosystem and, consequently,ecosystem function and services. As global warming is continuously increasing, the impact of global change oninfectious disease patterns is important to monitor in Baltic key species in the future.
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| 5. |
- Stokholm, Iben, et al.
(author)
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Phylogenomic insights to the origin and spread of phocine distemper virus in European harbour seals in 1988 and 2002
- 2019
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In: Diseases of Aquatic Organisms. - : Inter-Research Science Center. - 0177-5103 .- 1616-1580. ; 133, s. 47-56
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Journal article (peer-reviewed)abstract
- © Inter-Research 2019 · www.int-res.com The 1988 and 2002 phocine distemper virus (PDV) outbreaks in European harbour seals Phoca vitulina are among the largest mass mortality events recorded in marine mammals. Despite its large impact on harbour seal population numbers, and 3 decades of studies, many questions regarding the spread and temporal origin of PDV remain unanswered. Here, we sequenced and analysed 7123 bp of the PDV genome, including the coding and non-coding regions of the entire P, M, F and H genes in tissues from 44 harbour seals to shed new light on the origin and spread of PDV in 1988 and 2002. The phylogenetic analyses trace the origin of the PDV strain causing the 1988 outbreak to between June 1987 and April 1988, while the origin of the strain causing the 2002 outbreak can be traced back to between July 2001 and April 2002. The analyses further point to several independent introductions of PDV in 1988, possibly linked to a southward mass immigration of harp seals in the winter and spring of 1987−1988. The vector for the 2002 outbreak is unknown, but the epidemiological analyses suggest the subsequent spread of PDV from the epicentre in the Kattegat, Denmark, to haul-out sites in the North Sea through several independent introductions.
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