{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T17:29:36Z","timestamp":1790789376041,"version":"4.1.0"},"reference-count":36,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2024,10,10]],"date-time":"2024-10-10T00:00:00Z","timestamp":1728518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Lower Saxony Ministry of Food, Agriculture and Consumer Protection, Germany"},{"name":"Open Access Publication Fund of the University of Veterinary Medicine Hannover, Foundation"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Harbour seals (Phoca vitulina) are the most common pinniped species in the Wadden Sea of Schleswig-Holstein, Hamburg and Lower Saxony, Germany. Their numbers have recovered after significant depletion due to viral outbreaks and effects of anthropogenic activities like pollution and habitat disturbance. Within the Wadden Sea National Park of Lower Saxony the harbour seal is protected. As a top predator in the Wadden Sea ecosystem, the harbour seal is a sentinel species for the state of the environment. Between 2015 and 2017, a total of 80 stranded dead harbour seals were collected along the coastline of Lower Saxony and submitted for pathological investigations. Of these, 70 seals were born in the same year (0\u20137 months, age group 1) and eight in the previous year (8\u201319 months, age group 2), due to high mortality rates in these age groups. However, two perennial animals were also available for examination during this period, one of which was in good nutritional condition. Many of the seals that had been mercy-killed and found dead were in poor nutritional status. Histopathological, microbiological, parasitological and virological examinations were conducted on 69 individuals (86% (69\/80)) in a suitable state of preservation. Respiratory tract parasitosis, cachexia, and bronchopneumonia were the most common causes of death or disease. Overall, there was no evidence of a relapse of a viral disease outbreak. Macrowaste, such as plastic waste or fishery-related debris, were not found in any gastrointestinal tract of the animals examined. There was also no evidence of grey seal predation. Weakness and cachexia were prominent causes of disease and death in harbour seals found within a few weeks after birth, but bronchopneumonia and septicaemia also developed in slightly older animals. Frequently found microbial pathogens in seals from Lower Saxony were similar to those found in other studies on seals from the Wadden Sea region in Schleswig-Holstein, for example streptococci and Escherichia coli\/v. haemolytica, Brucella spp. and Erysipelothrix rhusiopathiae, potentially human pathogenic germs. The results of the examinations of dead harbour seals from Lower Saxony show that pathological investigations on a representative number of animals deliver urgently needed information on the health status of the population. The results represent an important contribution to the state of the top predators of the Wadden Sea as part of the obligations within the Trilateral Wadden Sea Agreement, Oslo and Paris Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and the Marine Framework Directive. The investigations should be continued as a matter of urgency and the stranding network should be expanded.<\/jats:p>","DOI":"10.3390\/ani14202920","type":"journal-article","created":{"date-parts":[[2024,10,11]],"date-time":"2024-10-11T03:53:47Z","timestamp":1728618827000},"page":"2920","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Investigations on the Health Status and Infection Risk of Harbour Seals (Phoca vitulina) from Waters of the Lower Saxon Wadden Sea, Germany"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2556-3948","authenticated-orcid":false,"given":"Ursula","family":"Siebert","sequence":"first","affiliation":[{"name":"Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover Foundation (TiHo), 25761 Buesum, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9037-9733","authenticated-orcid":false,"given":"Jan","family":"Lakemeyer","sequence":"additional","affiliation":[{"name":"Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover Foundation (TiHo), 25761 Buesum, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0388-9645","authenticated-orcid":false,"given":"Martin","family":"Runge","sequence":"additional","affiliation":[{"name":"Food and Veterinary Institute Braunschweig\/Hannover, Lower Saxony State Office for Consumer Protection and Food Safety (LAVES), 30173 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peter","family":"Lienau","sequence":"additional","affiliation":[{"name":"Seehundstation Nationalpark-Haus Norden-Norddeich, 26506 Norden, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silke","family":"Braune","sequence":"additional","affiliation":[{"name":"Food and Veterinary Institute Braunschweig\/Hannover, Lower Saxony State Office for Consumer Protection and Food Safety (LAVES), 30173 Hannover, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edda","family":"Bartelt","sequence":"additional","affiliation":[{"name":"Institute for Fish and Fishery Products Cuxhaven, LAVES, 27472 Cuxhaven, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miguel L.","family":"Grilo","sequence":"additional","affiliation":[{"name":"Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover Foundation (TiHo), 25761 Buesum, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ralf","family":"Pund","sequence":"additional","affiliation":[{"name":"Institute for Fish and Fishery Products Cuxhaven, LAVES, 27472 Cuxhaven, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,10,10]]},"reference":[{"key":"ref_1","unstructured":"Galatius, A., Brasseur, S., Hamm, T., Je\u00df, A., Meise, K., Meyer, J., Schop, J., Siebert, U., Stejskal, O., and Teilmann, J. (2023). Survey results of harbour seals in the Wadden Sea in 2023. The Population Continues to Decline, Common Wadden Sea Secretariat."},{"key":"ref_2","first-page":"50","article-title":"The effect of hunting on the further existence of a harbour seal population in the Dutch Wadden Sea","volume":"48","author":"Reijnders","year":"1983","journal-title":"Z. S\u00e4ugetierkd."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/0166-445X(89)90008-8","article-title":"Polychlorinated biphenyl (PCB) contaminated fish induces vitamin A and thyroid hormone deficiency in the common seal (Phoca vitulina)","volume":"15","author":"Brouwer","year":"1989","journal-title":"Aquat. Toxicol."},{"key":"ref_4","unstructured":"Narberhaus, I., Krause, J., and Bernitt, J. (2012). Chapter VII Species Profiles marine mammals. Threatened Biodiversity in the German North and Baltic Seas\u2014Sensitivities towards Human Activities and the Effects of Climate Change, Nature Conservation and Biodiversity."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"115","DOI":"10.3354\/dao068115","article-title":"A review of the 1988 and 2002 phocine distemper virus epidemics in European harbour seals","volume":"68","author":"Dietz","year":"2006","journal-title":"Dis. Aquat. Org."},{"key":"ref_6","unstructured":"Terio, K.A., McAloose, D., and St. Leger, J. (2018). Pinnipediae. Pathology of Wildlife and Zoo Animals, Academic Press. Chapter 23."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"684","DOI":"10.3201\/eid2104.141484","article-title":"Influenza A (H10N7) virus in dead harbour seals, Denmark","volume":"21","author":"Krog","year":"2015","journal-title":"Emerg. Infect. Dis."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.jcpa.2007.04.018","article-title":"Pathological findings in harbour seals (Phoca vitulina): 1996\u20132005","volume":"137","author":"Siebert","year":"2007","journal-title":"J. Comp. Path."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2588","DOI":"10.1002\/ece3.4923","article-title":"Long-term sound and movement recording tags to study natural behavior and reaction to ship noise of seals","volume":"9","author":"Mikkelsen","year":"2019","journal-title":"Ecol. Evol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2893","DOI":"10.1007\/s11356-020-10610-9","article-title":"Opportunistically collected data from aerial surveys reveal spatio-temporal distribution patterns of marine debris in German waters","volume":"28","author":"Unger","year":"2020","journal-title":"Environ. Sci. Poll. Res."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Philipp, C., Unger, B., and Siebert, U. (2022). Occurrence of Microplastics in Harbour Seals (Phoca vitulina) and Grey Seals (Halichoerus grypus) from German Waters. Animals, 12.","DOI":"10.3390\/ani12050551"},{"key":"ref_12","first-page":"12","article-title":"Behavioural and pathological insights into a case of active cannibalism by a grey seal (Halichoerus grypus) on Helgoland, Germany","volume":"148\u2013149","author":"Gross","year":"2019","journal-title":"J. Sea Res."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"van Neer, A., Gross, S., Kesselring, T., Grilo, M.L., Ludes-Wehrmeister, E., Roncon, G., and Siebert, U. (2021). 2021. Assessing seal carcasses potentially subjected to grey seal predation. Sci. Rep., 11.","DOI":"10.1038\/s41598-020-80737-9"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Rohner, S., H\u00fclsk\u00f6tter, K., Gross, S., Wohlsein, P., Abdulmawjood, A., Pl\u00f6tz, M., Verspohl, J., Haas, L., and Siebert, U. (2020). Male grey seal commits fatal sexual interaction with adult female harbour seals in the German Wadden Sea. Sci. Rep., 10.","DOI":"10.1038\/s41598-020-69986-w"},{"key":"ref_15","unstructured":"He\u00dfe, E., Siebert, U., and Gilles, A. (2024). Trophic ecology of marine mammals with competition potential under resource-limited conditions in the southern North Sea. Front. Mar. Sci., submitted."},{"key":"ref_16","unstructured":"IJsseldijk, L.L., Brownlow, A.C., and Mazzariol, S. (2023, December 14). Best Practice on Cetacean Postmortem Investigation and Tissue Sampling. Bonn, Monaco: ASCOBANS and ACCOBAMS Document, ASCOBANS MOP9\/Doc.6.2.5b. Available online: https:\/\/accobams.org\/wp-content\/uploads\/2021\/07\/Best-practices-on-cetacean-post-mortem-investigation.pdf."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.vetmic.2015.11.017","article-title":"Phocine distemper virus (PDV) seroprevalence as predictor for future outbreaks in harbour seals","volume":"183","author":"Dupke","year":"2016","journal-title":"Vet. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"20211969","DOI":"10.1098\/rspb.2021.1969","article-title":"Emergence and radiation of distemper viruses in terrestrial and marine mammals","volume":"288","author":"Stokholm","year":"2021","journal-title":"Proc. R. Soc. B"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"720","DOI":"10.3201\/eid2104.141675","article-title":"Avian Influenza A (H10N7) Virus\u2013Associated Mass Deaths among Harbor Seals","volume":"21","author":"Bodewes","year":"2015","journal-title":"Emerg. Inf. Dis."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"725","DOI":"10.1080\/22221751.2022.2043726","article-title":"Infections with Highly Pathogenic Avian Influenza A Virus (HPAIV) H5N8 in Harbor Seals at the German North Sea Coast","volume":"11","author":"Postel","year":"2022","journal-title":"Emerg. Microb. Inf."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1666","DOI":"10.1128\/jcm.34.7.1666-1671.1996","article-title":"Detection analysis of diverse herpesviral species by consensus primer PCR","volume":"34","author":"VanDevanter","year":"1996","journal-title":"J. Clin. Microbiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1053\/jcpa.2001.0547","article-title":"Post-mortem findings and causes of death of harbour porpoises (Phocoena phocoena) stranded from 1990 to 2000 along the coastlines of Belgium and Northern France","volume":"126","author":"Jauniaux","year":"2002","journal-title":"J. Comp. Pathol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"721","DOI":"10.1136\/vr.146.25.721","article-title":"Pulmonary pathology of harbour porpoises stranded in England and Wales between 1990 and 1996","volume":"146","author":"Jepson","year":"2000","journal-title":"Vet. Rec."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1177\/0300985820972454","article-title":"Challenges in the assessment of bycatch: Postmortem findings in harbor porpoises (Phocoena phocoena) retrieved from gillnets","volume":"58","author":"IJsseldijk","year":"2021","journal-title":"Vet. Pathol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1578\/AM.34.2.2008.149","article-title":"Differential hematology profiles differential hematology profiles of free-ranging, rehabilitated, and captive harbor seals (Phoca vitulina) of the German North Sea","volume":"34","author":"Hasselmeier","year":"2008","journal-title":"Aquat. Mam."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"200","DOI":"10.1016\/j.marpolbul.2012.11.035","article-title":"Plastic ingestion by harbour seals (Phoca vitulina) in The Netherlands","volume":"67","author":"Rebolledo","year":"2013","journal-title":"Mar. Pollut. Bull."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1002\/ieam.5630030412","article-title":"Microplastic-an emerging contaminant of potential concern?","volume":"3","author":"Browne","year":"2007","journal-title":"Integr. Environ. Assess. Manag."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1542","DOI":"10.1111\/mms.12111","article-title":"Direct evidence for gray seal (Halichoerus grypus) predation and scavenging on harbor porpoises (Phocoena phocoena)","volume":"30","author":"Bouveroux","year":"2014","journal-title":"Mar. Mammal Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"20142429","DOI":"10.1098\/rspb.2014.2429","article-title":"Exposing the grey seal as a major predator of harbour porpoises","volume":"282","author":"Leopold","year":"2015","journal-title":"Proc. R. Soc. B"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"485","DOI":"10.3201\/eid0904.020576","article-title":"Human neurobrucellosis with intracerebral granuloma caused by a marine mammal Brucella spp.","volume":"9","author":"Sohn","year":"2003","journal-title":"Emerg. Inf. Dis."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4363","DOI":"10.1128\/JCM.00680-06","article-title":"Characterization of a Brucella sp. strain as a marine-mammal type despite isolation from a patient with spinal osteomyelitis in New Zealand","volume":"44","author":"McDonald","year":"2006","journal-title":"J. Clin. Microb."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"81","DOI":"10.3354\/dao01942","article-title":"Health risks for marine mammal workers","volume":"81","author":"Hunt","year":"2008","journal-title":"Dis. Aqua. Org."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1111\/j.1863-2378.2012.01492.x","article-title":"Marine mammal zoonoses: A review of disease manifestations","volume":"59","author":"Waltzek","year":"2012","journal-title":"Zoonoses Public Health"},{"key":"ref_34","first-page":"10","article-title":"Genome sequence of Streptococcus phocae subsp","volume":"2","author":"Suarez","year":"2014","journal-title":"salmonis strain C-4T, isolated from Atlantic salmon (Salmo salar). Genome Announc."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Numberger, D., Siebert, U., Fulde, M., and Valentin-Weigand, P. (2021). Streptococcal infections in marine mammals. Microorganisms, 9.","DOI":"10.3390\/microorganisms9020350"},{"key":"ref_36","first-page":"646","article-title":"Streptococcus phocae sp. nov., a new species isolated from clinical specimens from seals","volume":"44","author":"Skaar","year":"1994","journal-title":"Int. J. Sys. Evol. Microbiol."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/20\/2920\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:10:55Z","timestamp":1760112655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/14\/20\/2920"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,10,10]]},"references-count":36,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2024,10]]}},"alternative-id":["ani14202920"],"URL":"https:\/\/doi.org\/10.3390\/ani14202920","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,10,10]]}}}