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Udodenko YG, Solovyeva MA, Glazov DM, Klimov FV, Komov VT, Kamshilova TB, Rozhnov VV. Total mercury in fur, whiskers and whole blood of Caspian seals (Pusa capsica) from north-east of Caspian Sea (Kazakhstan). MARINE POLLUTION BULLETIN 2024; 205:116605. [PMID: 38889665 DOI: 10.1016/j.marpolbul.2024.116605] [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: 04/02/2024] [Revised: 06/12/2024] [Accepted: 06/13/2024] [Indexed: 06/20/2024]
Abstract
Total Mercury (THg) content was determined in the fur of 64 Caspian seals, in the whiskers of 59 individuals and whole blood of 29 individuals. The THg content in Caspian seal fur varied from 258 to 8511 μg/kg, in whiskers from 954 to 12,957 μg/kg, and in whole blood from 88 to 350 μg/l. There were no statistically significant differences in mercury concentration in biomaterial between males and females (Kruskal-Wallis test, p < 0.05). The 1-2-year-old seals contained less mercury compared to older seals. The THg content in Caspian seal samples was comparable to seals from different regions of North Eurasia. Four individuals had mercury concentrations in their fur above the threshold values that can lead to nervous system disorders (>5400 μg/kg).
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Affiliation(s)
- Yu G Udodenko
- I.D. Papanin Institute for Biology of Inland Waters RAS, Borok, Russia; Cherepovets State University, Cherepovets, Russia.
| | - M A Solovyeva
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
| | - D M Glazov
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
| | - F V Klimov
- "Kazakhstan Agency of Applied Ecology" LLP, Almaty, Kazakhstan
| | - V T Komov
- I.D. Papanin Institute for Biology of Inland Waters RAS, Borok, Russia; Cherepovets State University, Cherepovets, Russia
| | - T B Kamshilova
- I.D. Papanin Institute for Biology of Inland Waters RAS, Borok, Russia
| | - V V Rozhnov
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
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Tang KN, Adkesson MJ, Cárdenas-Alayza S, Adamovicz L, Deming AC, Wellehan JFX, Childress A, Cortes-Hinojosa G, Colegrove K, Langan JN, Allender MC. Otariid gammaherpesvirus 1 in South American fur seals (Arctocephalus australis) and a novel related herpesvirus in free-ranging South American sea lions (Otaria byronia): Prevalence and effects of age, sex, and sample type. PLoS One 2024; 19:e0299404. [PMID: 38446776 PMCID: PMC10917305 DOI: 10.1371/journal.pone.0299404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 02/08/2024] [Indexed: 03/08/2024] Open
Abstract
Otariid gammaherpesvirus 1 (OtGHV1) is associated with high rates of urogenital carcinoma in free-ranging California sea lions (Zalophus californianus; CSL), and until recently was reported only in the Northern Hemisphere. The objective of this study was to survey free-ranging South American sea lions (Otaria byronia; SASL) and South American fur seals (Arctocephalus australis: SAFS) in Punta San Juan, Peru for OtGHV1 and to determine prevalence characteristics. Twenty-one percent (14/67) of urogenital swabs collected over three years (2011, 2014, 2015) from live pinnipeds of both species tested positive with a pan-herpesvirus conventional PCR. Sequencing of SAFS amplicons revealed 100% homology to OtGHV1 at the DNA polymerase, glycoprotein B, and viral bcl2-like genes. Sequencing of SASL amplicons revealed a novel related virus, herein called Otariid gammaherpesvirus 8 (OtGHV8). For comparison of sample sites, urogenital, conjunctival, and oropharyngeal swabs collected from 136 live pinnipeds of both species at Punta San Juan between 2011-2018 were then assayed using quantitative PCR for a segment of the OtGHV1/8 DNA polymerase gene using a qPCR assay now determined to cross-react between the two viruses. In total, across both species, 38.6% (51/132) of urogenital swabs, 5.6% (4/71) of conjunctival swabs, and 1.1% (1/90) of oropharyngeal swabs were positive for OtGHV1/8, with SASL only positive on urogenital swabs. Results from SASL were complicated by the finding of OtGHV8, necessitating further study to determine prevalence of OtGHV1 versus OtGHV8 using an alternate assay. Results from SAFS suggest a potential relationship between OtGHV1 in SAFS and CSL. Though necropsy surveillance in SAFS is very limited, geographic patterns of OtGHV1-associated urogenital carcinoma in CSL and the tendency of herpesviruses to cause more detrimental disease in aberrant hosts suggests that it is possible that SAFS may be the definitive host of OtGHV1, which gives further insight into the diversity and phyogeography of this clade of related gammaherpesviruses.
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Affiliation(s)
- Karisa N. Tang
- Chicago Zoological Society, Brookfield Zoo, Brookfield, IL, United States of America
- Illinois Zoological and Aquatic Animal Residency, Urbana, IL, United States of America
- A. Watson Armour III Center for Animal Health and Welfare, John G. Shedd Aquarium, Chicago, IL, United States of America
| | - Michael J. Adkesson
- Chicago Zoological Society, Brookfield Zoo, Brookfield, IL, United States of America
| | - Susana Cárdenas-Alayza
- Centro para la Sostenibilidad Ambiental, Universidad Peruana Cayetano Heredia, Lima, Peru
- Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Laura Adamovicz
- Wildlife Epidemiology Laboratory, University of Illinois College of Veterinary Medicine, Urbana, IL, United States of America
| | - Alissa C. Deming
- Pacific Marine Mammal Center, Laguna Beach, CA, United States of America
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States of America
| | - James F. X. Wellehan
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States of America
| | - April Childress
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States of America
| | - Galaxia Cortes-Hinojosa
- Escuela de Medicina Veterinaria, Facultad de Agronomía e Ingeniería Forestal, Facultad de Ciencias Biológicas y Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Kathleen Colegrove
- Zoological Pathology Program, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois, Brookfield, IL, United States of America
| | - Jennifer N. Langan
- Chicago Zoological Society, Brookfield Zoo, Brookfield, IL, United States of America
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, United States of America
| | - Matthew C. Allender
- Chicago Zoological Society, Brookfield Zoo, Brookfield, IL, United States of America
- Wildlife Epidemiology Laboratory, University of Illinois College of Veterinary Medicine, Urbana, IL, United States of America
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Bodini A, Pereira D, Scotti M. The decline of kilkas, sturgeons and seals in the Caspian Sea: The potential of qualitative loop analysis for the cumulative assessment of multiple drivers of stress. MARINE POLLUTION BULLETIN 2024; 200:116091. [PMID: 38335632 DOI: 10.1016/j.marpolbul.2024.116091] [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: 10/18/2023] [Revised: 01/22/2024] [Accepted: 01/27/2024] [Indexed: 02/12/2024]
Abstract
Multiple stressors often act concomitantly on ecosystems but detection of species responses follows the "single species-single driver" strategy, and cumulative impacts are seldom considered. During 1990-2010, multiple perturbations in the Caspian Sea, led to the decline of kilka, sturgeon and Caspian seal populations. Specific causes for their collapse were identified but a cumulative assessment has never been carried out. Using loop analysis, a qualitative modelling technique suitable in poor-data contexts, we show how multiple drivers can be combined to assess their cumulative impact. We confirm that the decline of kilka, sturgeon and Caspian seal populations is compatible with a net effect of the concomitant perturbations. Kilkas collapse was certainly due to the outburst of M. leidyi and overfishing. In addition, the excess nutrient might have conspired to reduce these populations. The interplay between concurrent drivers produces trade-offs between opposite effects and ecosystem management must face this challenge.
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Affiliation(s)
- Antonio Bodini
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy.
| | - Daniel Pereira
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parma, Italy; UMR PACEA 5199, University of Bordeaux, France
| | - Marco Scotti
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany; Institute of Biosciences and Bioresources, National Research Council of Italy, 50019 Sesto Fiorentino, (Firenze), Italy
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Hoseini SM, Namroodi S, Sayadshirazi A, Zaccaroni A. Trace Elements and Contaminants Concentrations in Tissues of Caspian Seals ( Pusa caspica) along the Iranian Coast. TOXICS 2022; 11:39. [PMID: 36668765 PMCID: PMC9865950 DOI: 10.3390/toxics11010039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/05/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
The Caspian seal (Pusa caspica) is an endangered species that only lives in the Caspian Sea. Little information is available on its exposure to contaminants, and no data exists for Southern sub-populations. From 2011 to 2016, tissues samples were collected from 20 Caspian seals to (i) Define the concentration of trace elements in five different matrices and the concentration of 30 pesticides in their blubber; (ii) Determine whether differences in contaminant concentrations are age- or sex-related; (iii) Evaluate if detected concentrations can represent a risk to the species. Age- and sex-related variations were detected for Zn and Hg in the blubber and Fe in the kidney by age only. Exceptionally high Hg concentrations and low levels of hepatic Zn were detected, raising some concern about the reproductive health of seals. Similarly, the DDTs levels detected were in the range of adverse reproductive effects in marine mammals. Based on these results, potentially adverse effects on the immune and endocrine systems of the Caspian seal cannot be ruled out. Therefore, it is of the utmost importance that pollutant monitoring becomes an integral component of conservation strategies for the Caspian seal.
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Affiliation(s)
- Seyedeh Malihe Hoseini
- Department of Environmental Sciences, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan 4913815739, Iran
| | - Somayeh Namroodi
- Department of Environmental Sciences, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan 4913815739, Iran
| | | | - Annalisa Zaccaroni
- Department Veterinary Medical Sciences, University of Bologna, 47042 Cesenatico, Italy
- MarLab, 06250 Mougins, France
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Omidzahir S, Sayyad Shirazi A, Hosseini SM. Morphological and molecular identification of Corynosoma caspicum, and its histopathological effect on the intestinal tissue of a Caspian seal ( Pusa caspica). IRANIAN JOURNAL OF VETERINARY RESEARCH 2020; 21:308-313. [PMID: 33584844 PMCID: PMC7871739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 10/04/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Corynosoma is a parasite from the Acanthocephala phylum with worldwide distribution. Corynosoma parasites are found in pinnipeds as their definitive host. AIMS This study aimed to investigate the morphological and molecular characteristics of Corynosoma, and its histopathological effect on the intestinal tissue of Pusa caspica. METHODS A severe Corynosoma infection was observed in the small intestine of a juvenile male Caspian seal (P. caspica). The morphological descriptions were done using light microscopy, and scanning electron microscopy (SEM). The molecular diagnosis was performed using partial sequences of internal transcribed spacer 1 (ITS1) and 5.8S ribosomal RNA (rRNA) gene. RESULTS According to the results, the Corynosoma specimens were identified as Corynosoma caspicum. The histopathological inspection of intestinal tissue revealed lesions in epithelial cells, mucosa, submucosa and muscle layers, destruction of intestinal glands, and infiltration of inflammatory cells. CONCLUSION Presence of such a severe infection in one of the individual Caspian seals can suggest the possibility of morbidity among other seals in the landlocked Caspian Sea. Thus, further research on their parasite infections is required for understating the status of the Caspian seal population and conserving this endangered species.
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Affiliation(s)
- Sh. Omidzahir
- Department of Marine Biology, Faculty of Marine Sciences, University of Mazandaran, Babolsar, Iran
| | - A. Sayyad Shirazi
- Caspian Seal Rehabilitation and Research Center, Ashooradeh Island, Iran
| | - S. M. Hosseini
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, Babol Branch, Islamic Azad University, Babol, Iran
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Tasmagambetova A, Tovassarov A, Bihan-Poudec AC, Bissariyeva S, Akberliyev A. Assessment of the Current State of the Caspian Sea and the Caspian Seal Habitat Analysis. EURASIAN CHEMICO-TECHNOLOGICAL JOURNAL 2019. [DOI: 10.18321/ectj827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
This article is devoted to the determination of heavy metals and harmful organic compounds in sea water – the habitat of the Caspian seal. The group of the most common heavy metals, according to many authors, includes manganese, nickel, zinc, iron, cadmium, lead, copper and their salts, characterized by long-term preservation and accumulation in water, sediments and hydrobionts. The studies were conducted from February 7–12, 2017 on the route from the Kalamkas (Kazakhstan) field through the islands of Kulaly to the village of Bautino. Water samples were taken 10‒20 cm below the sea ice and surface level, each sample was taken in 2 replicates: one for the Kazakhstan laboratory in Almaty and one for the French independent laboratory. Water samples were analyzed for the content of 13 heavy metals such as – Co, Cu, Ti, Bi, Ag, V, Al, Be, Sb, Sn, Fe, Cr, Mo. It was established that in all water samples the content of vanadium exceeds the maximum permissible concentration (MPC) level by 1.5–7.4 times, beryllium ‒ 140–445 times, antimony 13.2–17.2 times. The maximum concentrations of the V and Be contents were found in water samples taken at sampling points No. 1 and 2, and Sb ‒ at points No. 1.6, 7.8. Cobalt, copper, iron and chromium were not detected in the samples presented. The content of other metals (Ti, Bi, Ag, Al, Sn, Mo) was significantly below the permissible levels or below the detection limits of the method. All samples of sea water are contaminated by several organic chemical pollutants, to various degrees and from different origins. Data on the accumulation of petroleum hydrocarbons and heavy metals in the habitat of Caspian seals characterize the toxicological situation in the study region.
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Namroodi S, Shirazi AS, Khaleghi SR, N. Mills J, Kheirabady V. Frequency of exposure of endangered Caspian seals to Canine distemper virus, Leptospira interrogans, and Toxoplasma gondii. PLoS One 2018; 13:e0196070. [PMID: 29698496 PMCID: PMC5919510 DOI: 10.1371/journal.pone.0196070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 04/05/2018] [Indexed: 11/19/2022] Open
Abstract
Canine distemper virus (CDV), Leptospira interrogans, and Toxoplasma gondii are potentially lethal pathogens associated with decline in marine mammal populations. The Caspian Sea is home for the endangered Caspian seal (Pusa caspica). In the late 1990s and early 2000s, CDV caused a series of mortality events involving at least several thousand Caspian seals. To assess current infection status in Caspian seals, we surveyed for antibodies to three pathogens with potential to cause mortality in marine mammals. During 2015–2017, we tested serum samples from 36, apparently healthy, Caspian seals, accidentally caught in fishing nets in the Caspian Sea off Northern Iran, for antibodies to CDV, L. interrogans, and T. gondii, by virus neutralization, microscopic agglutination, and modified agglutination, respectively. Twelve (33%), 6 (17%), and 30 (83%) samples were positive for CDV, L. interrogans and T. gondii antibodies, respectively. The highest titers of CDV, L. interrogans, and T. gondii antibodies were 16, 400, and 50, respectively. Frequencies of antibody to these pathogens were higher in seals >1 year old compared to seals <1 year old. Two serovars of L. interrogans (Pomona and Canicola) were detected. Our results suggest a need for additional studies to clarify the impact of these pathogens on Caspian seal population decline and the improvement of management programs, including systematic screening to detect and protect the remaining population from disease outbreaks.
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MESH Headings
- Aging
- Animals
- Antibodies, Bacterial/blood
- Antibodies, Protozoan/blood
- Antibodies, Viral/blood
- Distemper/epidemiology
- Distemper/pathology
- Distemper/virology
- Distemper Virus, Canine/immunology
- Distemper Virus, Canine/pathogenicity
- Dogs
- Leptospira interrogans/immunology
- Leptospira interrogans/pathogenicity
- Leptospirosis/epidemiology
- Leptospirosis/pathology
- Leptospirosis/veterinary
- Seals, Earless/microbiology
- Seals, Earless/parasitology
- Seals, Earless/virology
- Toxoplasma/immunology
- Toxoplasma/pathogenicity
- Toxoplasmosis, Animal/epidemiology
- Toxoplasmosis, Animal/parasitology
- Toxoplasmosis, Animal/pathology
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Affiliation(s)
- Somayeh Namroodi
- Department of Environmental sciences, Faculty of veterinary medicine, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Golestan Province, Iran
- * E-mail:
| | - Amir S. Shirazi
- Caspian Seal Treatment and Research Center, Ashooradeh Island, Gorgan, Golestan Province, Iran
| | - Seyyed Reza Khaleghi
- Department of Environmental sciences, Faculty of veterinary medicine, Gorgan University of Agricultural Sciences & Natural Resources, Gorgan, Golestan Province, Iran
| | - James N. Mills
- Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, Georgia, United States of America
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Trukhanova IS, Grachev AI, Somov AG, Burkanov VN, Laidre KL, Boveng PL. The commercial harvest of ice-associated seals in the Sea of Okhotsk, 1972-1994. PLoS One 2017; 12:e0182725. [PMID: 28796843 PMCID: PMC5552157 DOI: 10.1371/journal.pone.0182725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/24/2017] [Indexed: 11/23/2022] Open
Abstract
Sealing log books from 75 out of 79 commercial harvest cruises carried out between 1972 and 1994 in the Sea of Okhotsk, Russia, were analyzed to describe spatial and temporal allocation of ice-associated seal harvest effort, species composition of catches, total harvest rates, and related parameters for species including ringed (Pusa hispida), ribbon (Histriophoca fasciata), bearded (Erignathus barbatus) and spotted (Phoca largha) seal. Variations in catch per unit effort were explored in relation to year, sea ice conditions, day of the year, and geographic location. In most years, the harvest was predominantly represented by ringed seals (mean = 0.43, range 0.25–0.67), followed by ribbon (mean = 0.31, range 0.15–0.43), spotted (mean = 0.19, range 0.11–0.35) and bearded seals (mean = 0.07, range 0.03–0.14). The struck-and-lost percentages were as high as 30–35% for ringed, bearded and spotted seals and 15–20% for ribbon seals. Catch per unit effort (number of seals/skiff*day) for ringed, ribbon, and spotted seals had a similar seasonal pattern with a distinct spike in catches for spotted seals in the first week of May, for ribbon seals in the last week of May, and for ringed seals in the second week of June. Catches of bearded seals showed a less pronounced temporal structure with a gradual increase toward the end of the harvest season in the majority of years. Spatial distribution of harvest effort followed closely with seal distribution obtained from aerial surveys. These data could be used as a source of information on seal herd location throughout the breeding and molting seasons and for more complex demographic or life-table models. We did not find any evidence of the decline of catch per unit effort over the study period. Timely introduction of state regulations and efficient harvest management apparently prevented severe depletion of ice-associated seal populations in the Sea of Okhotsk during the periods of their intense exploitation.
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Affiliation(s)
- Irina S. Trukhanova
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, Washington, United States of America
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
- * E-mail:
| | - Aleksey I. Grachev
- Laboratory of coastal resources, Magadan Research Institute of Fisheries and Oceanography (MagadanNIRO), Magadan, Russia
| | - Aleksandr G. Somov
- Laboratory of marine mammals, Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), Moscow, Russia
| | - Vladimir N. Burkanov
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
- Kamchatka Branch of the Pacific Geographical Institute Far East Branch of Russian Academy of Sciences, Petropavlovsk-Kamchatskiy, Russia
| | - Kristin L. Laidre
- Polar Science Center, Applied Physics Laboratory, University of Washington, Seattle, Washington, United States of America
| | - Peter L. Boveng
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
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Wilson SC, Dolgova E, Trukhanova I, Dmitrieva L, Crawford I, Baimukanov M, Goodman SJ. Breeding behavior and pup development of the Caspian seal,Pusa caspica. J Mammal 2016. [DOI: 10.1093/jmammal/gyw176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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10
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Assessing the effects of demersal fishing and conservation strategies of marine mammals over a Patagonian food web. Ecol Modell 2016. [DOI: 10.1016/j.ecolmodel.2015.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Dmitrieva L, Härkönen T, Baimukanov M, Bignert A, Jüssi I, Jüssi M, Kasimbekov Y, Verevkin M, Vysotskiy V, Wilson S, Goodman SJ. Inter-year variation in pup production of Caspian seals Pusa caspica 2005–2012 determined from aerial surveys. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00689] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Wilson SC, Eybatov TM, Amano M, Jepson PD, Goodman SJ. The role of canine distemper virus and persistent organic pollutants in mortality patterns of Caspian seals (Pusa caspica). PLoS One 2014; 9:e99265. [PMID: 24987857 PMCID: PMC4079250 DOI: 10.1371/journal.pone.0099265] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 05/12/2014] [Indexed: 12/03/2022] Open
Abstract
Persistent organic pollutants are a concern for species occupying high trophic levels since they can cause immunosuppression and impair reproduction. Mass mortalities due to canine distemper virus (CDV) occurred in Caspian seals (Pusa caspica), in spring of 1997, 2000 and 2001, but the potential role of organochlorine exposure in these epizootics remains undetermined. Here we integrate Caspian seal mortality data spanning 1971–2008, with data on age, body condition, pathology and blubber organochlorine concentration for carcases stranded between 1997 and 2002. We test the hypothesis that summed PCB and DDT concentrations contributed to CDV associated mortality during epizootics. We show that age is the primary factor explaining variation in blubber organochlorine concentrations, and that organochlorine burden, age, sex, and body condition do not account for CDV infection status (positive/negative) of animals dying in epizootics. Most animals (57%, n = 67) had PCB concentrations below proposed thresholds for toxic effects in marine mammals (17 µg/g lipid weight), and only 3 of 67 animals had predicted TEQ values exceeding levels seen to be associated with immune suppression in harbour seals (200 pg/g lipid weight). Mean organonchlorine levels were higher in CDV-negative animals indicating that organochlorines did not contribute significantly to CDV mortality in epizootics. Mortality monitoring in Azerbaijan 1971–2008 revealed bi-annual stranding peaks in late spring, following the annual moult and during autumn migrations northwards. Mortality peaks comparable to epizootic years were also recorded in the 1970s–1980s, consistent with previous undocumented CDV outbreaks. Gompertz growth curves show that Caspian seals achieve an asymptotic standard body length of 126–129 cm (n = 111). Males may continue to grow slowly throughout life. Mortality during epizootics may exceed the potential biological removal level (PBR) for the population, but the low frequency of epizootics suggest they are of secondary importance compared to anthropogenic sources of mortality such as fishing by-catch.
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Affiliation(s)
- Susan C. Wilson
- Tara Seal Research Centre, Killyleagh, County Down, Northern Ireland, United Kingdom
- * E-mail: (SCW); (SJG)
| | | | - Masao Amano
- Faculty of Fisheries, Nagasaki University, Nagasaki, Japan
| | - Paul D. Jepson
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Simon J. Goodman
- School of Biology, University of Leeds, Leeds, United Kingdom
- * E-mail: (SCW); (SJG)
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Dmitrieva L, Kondakov AA, Oleynikov E, Kydyrmanov A, Karamendin K, Kasimbekov Y, Baimukanov M, Wilson S, Goodman SJ. Assessment of Caspian Seal By-Catch in an Illegal Fishery Using an Interview-Based Approach. PLoS One 2013; 8:e67074. [PMID: 23840590 PMCID: PMC3694144 DOI: 10.1371/journal.pone.0067074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Accepted: 05/13/2013] [Indexed: 11/20/2022] Open
Abstract
The Caspian seal (Pusa caspica) has declined by more than 90% since 1900 and is listed as endangered by IUCN. We made the first quantitative assessment of Caspian seal by-catch mortality in fisheries in the north Caspian Sea by conducting semi-structured interviews in fishing communities along the coasts of Russia (Kalmykia, Dagestan), Kazakhstan and Turkmenistan. We recorded a documented minimum by-catch of 1,215 seals in the survey sample, for the 2008–2009 fishing season, 93% of which occurred in illegal sturgeon fisheries. Due to the illegal nature of the fishery, accurately quantifying total fishing effort is problematic and the survey sample could reflect less than 10% of poaching activity in the north Caspian Sea. Therefore total annual by-catch may be significantly greater than the minimum documented by the survey. The presence of high by-catch rates was supported independently by evidence of net entanglement from seal carcasses, during a mass stranding on the Kazakh coast in May 2009, where 30 of 312 carcasses were entangled in large mesh sturgeon net remnants. The documented minimum by-catch may account for 5 to 19% of annual pup production. Sturgeon poaching therefore not only represents a serious threat to Caspian sturgeon populations, but may also be having broader impacts on the Caspian Sea ecosystem by contributing to a decline in one of the ecosystem’s key predators. This study demonstrates the utility of interview-based approaches in providing rapid assessments of by-catch in illegal small-scale fisheries, which are not amenable to study by other methods.
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Affiliation(s)
- Lilia Dmitrieva
- School of Biology, University of Leeds, Leeds, United Kingdom
- * E-mail: (LD); (SG)
| | - Andrey A. Kondakov
- Institute of Arid Zones, Southern Scientific Center of Russian Academy of Sciences, Rostov-on-Don, Russian Federation
| | - Eugeny Oleynikov
- Institute of Arid Zones, Southern Scientific Center of Russian Academy of Sciences, Rostov-on-Don, Russian Federation
| | | | | | - Yesbol Kasimbekov
- Institute of Hydrobiology and Ecology, Karasaysky Raion, Almaty, Kazakhstan
| | | | - Susan Wilson
- Tara Seal Research Centre, Killyleagh, County Down, Northern Ireland, United Kingdom
| | - Simon J. Goodman
- School of Biology, University of Leeds, Leeds, United Kingdom
- * E-mail: (LD); (SG)
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Reeves RR, McClellan K, Werner TB. Marine mammal bycatch in gillnet and other entangling net fisheries, 1990 to 2011. ENDANGER SPECIES RES 2013. [DOI: 10.3354/esr00481] [Citation(s) in RCA: 212] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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