Movements and diet of Weddell seals in the southern Weddell Sea

• Main Authors: Webb, Kristin, Wege, Mia, Bester, M. N., Bornemann, Horst
• Format: Conference Object
• Language: unknown
• Published: 2020
• Subjects: Antarc*; Antarctic; Antarctic Peninsula; Antarctica; Ross Sea; Sea ice; Weddell Sea; Weddell Seals
• Online Access: https://epic.awi.de/id/eprint/52852/; https://epic.awi.de/id/eprint/52852/1/Webb-etal-2020.pdf; https://hdl.handle.net/10013/epic.0495bfb3-8ba7-49f8-af93-bf2b44a2ebca

Satellite tracking and stable carbon (δ13C) and nitrogen (δ15N) isotope data were used to assess seasonal movements and trophic position of five Weddell seals (Leptonychotes weddellii) in the southern Weddell Sea in 2018. The seals travelled greatest overall distances in autumn and winter. Distances were shorter in spring and summer when seals spent a greater proportion of time hauled out on sea ice. Total distances travelled per day varied between sexes and over seasons. The seals’ haul out behaviour switched between primarily nocturnal (autumn and winter) to diurnal patterns (summer and spring). Location data indicated that polynyas were frequented more often in winter and autumn, and less often in spring although the marginal ice edges of the polynyas were still used to haul out. Average δ13C value where higher in seals sampled in the southern Weddell Sea (-21.43 ‰) compared to those in the Ross Sea (-24.3 ‰ – -22.5‰) and similar to seals sampled in the Western Antarctic Peninsula (-22.4‰ – -20.1‰). This highlights the seals’ preference for foraging near productive coastal zones and over enriched benthic communities. Weddell seals in our study area consume similar prey types as revealed by average δ15N values of 13.85 ‰, which are similar to those of Weddell seals in other areas of Antarctica.