Individual variability in diving, movement and activity patterns of adult bearded seals in Svalbard, Norway

• Published in: Scientific Reports
• Main Authors: Hamilton, Charmain D., Kovacs, Kit M., Lydersen, Christian
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2018
• Subjects: Article; Arctic; Norway; Svalbard; Arctic marine mammals; Erignathus barbatus; glacier; inuit
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6242851/; http://www.ncbi.nlm.nih.gov/pubmed/30451906; https://doi.org/10.1038/s41598-018-35306-6

Bearded seals are one of the least studied Arctic marine mammals, despite their circumpolar distribution and importance as a resource to Inuit communities. In this study, adult bearded seals (Erignathus barbatus) were equipped with GPS-Argos-CTD-SRDLs in Svalbard, Norway (2011–2012, n = 7) to document their diving, activity and movement patterns in a region where their habitat is changing rapidly. Five seals transmitted for > 8 months, sending 21,738 GPS-positions and 17,866 dives between July and April. The seals spent little time hauled out (≤ 5%). Diving, which occupied 74 ± 3% of their time, was generally shallow (24 ± 7 m, max: 391 m) and of short duration (6.6 ± 1.5 min, max: 24 min) with deeper, longer dives in winter/spring compared to summer. All seals occupied shallow, coastal areas and relatively small 50% home ranges (10–32 km2). However, individuals exhibited high degrees of specialization in their habitat use and diving behaviour, differing markedly with respect to proportions of benthic vs pelagic dives (range: 51–95% benthic dives), distance to glacier fronts (range: 3–22 km) and in the time spent at the bottom of dives (range: 43–77%). Having specialized strategies within a generalist population may help bearded seals adapt in a rapidly changing Arctic ecosystem.