Bearded seal ( Erignathus barbatus) birth mass and pup growth in periods with contrasting ice conditions in Svalbard, Norway

• Published in: Marine Mammal Science
• Main Authors: Kovacs, Kit M., Krafft, Bjørn A., Lydersen, Christian
• Other Authors: Norsk Polarinstitutt, Norges Forskningsråd
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2019
• Subjects: Arctic; Svalbard; Norway; bearded seal; Erignathus barbatus; glacier; Sea ice
• Online Access: http://dx.doi.org/10.1111/mms.12647; https://onlinelibrary.wiley.com/doi/pdf/10.1111/mms.12647; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/mms.12647

Abstract Global climate warming has caused major reductions in sea ice in the Arctic, posing a serious threat to ice‐associated marine mammals. Herein, novel data on birth mass and pup growth rates over a 15‐year period (1993–2007; 10 years with growth data) are reported for bearded seals, as well as initial behavioral responses by this species to major, local declines in sea‐ice in Svalbard, Norway. In total, 205 pups were captured; 64 of which were recaptured, some repeatedly, producing 85 growth intervals for nursing pups. Average birth mass of pups was 37.1 ± 3.8 ( SD ) kg (range 33–47 kg, n = 25); birth mass before vs. after the sea ice collapse (2006 onward) were not found to differ. Pups grew at a rate of 3.0 ± 0.7 kg/day (1.8–4.8 kg/day, n = 64) during the nursing period. LME models suggest that ice concentration did not affect the growth rate of pups. Most females shifted from traditional first‐year ice floes to glacier‐ice pieces for birthing and nursing their young, following the regional sea ice collapse. However, retraction of tidal glaciers will likely eliminate this replacement birthing and nursing habitat for bearded seals in Svalbard in the coming decades.