Dear MARMAM community,

my co-authors and I are happy to announce the publication of our new paper in Environmental International about “Variation in skull bone mineral density of ringed seals (Phoca hispida) from the Gulf of Bothnia and West Greenland between 1829 and 2019”

Schmidt, B., Sonne, C., Nachtsheim, D., Dietz, R., Oheim, R., Rolvien, T., Persson, S., Amling, M., Siebert, U., 2020. Variation in skull bone mineral density of ringed seals (Phoca hispida) from the Gulf of Bothnia and West Greenland between 1829 and 2019. Environ. Int., 143, 1-9. https://doi.org/10.1016/j.envint.2020.105968

Abstract

Bone is remodelled constantly through a balance of bone formation and resorption. This process can be affected

by various factors such as hormones, vitamins, nutrients and environmental factors, which can create an imbalance

resulting in systemic or local bone alteration. The aim of the present study was to analyse the changes in

bone mineral density (BMD) over time in skulls of ringed seals (Pusa hispida) from the Baltic and Greenland using

museum samples. Overall, 303 skulls (102 Male, 89 Female, 112 unknown) were used for bone investigations

and were divided into three periods according to collection year: before 1958 (n = 167), between 1958 and

1989 (n = 40) and after 1994 up to 2019 (n = 96). All skulls were examined by dual-energy X-ray absorptiometry

to obtain the BMD. Skull BMD of the Baltic seals was positively correlated with the historical polychlorinated

biphenyls (PCB) contamination having potential effects on the constitution of bones. BMD fluctuated

between the three study periods (LM: p-value < 0.001, F-value = 47.5) with the lowest BMD found between

1897 and 1957, in the Gulf of Bothnia, where the highest peak of contaminant concentration was in the second

period. BMD levels increased with increasing PCB concentration (LM: p < 0.001). The Greenland population

showed significant lower BMD levels in the pollution and post-pollution period than the Baltic population (LM:

p < 0.001). It also revealed a higher BMD in males than in females (LM: p=0.03). In conclusion, the variations

between 1829 and 2019 in the Baltic Sea and Greenland may to a certain extent reflect normal fluctuations;

however, this study revealed several factors affecting BMD, including sex and PCB levels.

The publication is freely available at:

https://www.sciencedirect.com/science/article/pii/S0160412020319231

Britta Schmidt

Marine Biologist

University of Veterinary Medicine Hannover, Foundation

Institute for Terrestrial and Aquatic Wildlife Research (ITAW), Germany