Aage Kristian Olsen Alstrup

Prevalence of skull pathologies in European harbour seals (Phoca vitulina) during 1981-2014

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  • Cino Pertoldi, Sektion for Biologi og Miljøteknologi, Aalborg University, Denmark
  • Lasse Fast Jensen
  • ,
  • Aage Kristian Olsen Alstrup
  • Ole Lajord Munk
  • Trine Bæk Pedersen, Aalborg University, Denmark
  • Christian Sonne
  • Rune Dietz
  • Tobias Daugaard-Petersen
  • ,
  • Hanne Ellen Kortegaard, Københavns Universitet, Denmark
  • Morten Tange Olsen
  • ,
  • Karin Charlotte Hårding, Sweden
  • Trine Hammer Jensen, Aalborg Zoo, Denmark
Harbour seals (Phoca vitulina) inhabit the seas surrounding Denmark and are an important top predator in the marine food chain. This trophic position exposes them to environmental contaminants with disease epidemics and hunting being additional threats to this population. It is therefore important to study how environmental pollution at the current order of magnitude affects the health of the population. Earlier studies have shown that occurrence of periodontitis could be linked to the amount of pollution the seals were subjected to. In order to investigate this further, 380 skulls and 141 mandibles of harbour seals (Phoca vitulina) from the Wadden Sea, the Limfjord and Kattegat, collected during the period: 1970-2014 were examined. The skulls were examined for pathological lesions. The Hounsfield Units (HU), which are correlated to the bone mineral density (BMD) were measured in a subsample (n=34) using CT-scans. The macroscopic examination revealed (with the exception of the Swedish part of Kattegat) a significant increase of pathological lesions over the study period of 1981-2014. The examination of HU showed that median HU measured at multiple sites was highest in the healthy skulls compared to skulls with one or more of the lesions. A discriminant analysis allowed high discriminatory capacity to separate healthy skulls from the skulls with pathologies, simply by the utilization of the HU data. Former studies of BMD in marine mammals have shown that exposure to environmental chemicals alter BMD and cause periodontitis. The present study, based on temporal and spatial trends in BMD, confirms the results of previous studies.
Original languageEnglish
JournalActa Theriologica
Pages (from-to)1-9
ISSN0001-7051
DOIs
Publication statusPublished - 1 Nov 2017

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