Isotopic ecology of the Weddell seal (Leptonychotes weddellii) in Terre Adélie, East Antarctica.

This study characterises the trophic ecology of the Weddell seal (Leptonychotes weddellii) in Terre Adelie, East Antarctica, using stable carbon (δ13C) and nitrogen (δ15N) isotope ratios measured in whole blood. Blood samples were collected from 309 individuals between 2006 and 2024, spanning three biological groups (adult females, adult males and pups) and two seasonal sampling windows: Winter/Spring (September-December) and Summer (January-March).

The study aimed to:
(i) document isotopic niche variability across life stages, sexes and seasons;
(ii) assess interannual variability in δ13C and δ15N in adult females over an 18-year time series bracketing the calving of the Mertz Glacier Tongue in February 2010; and
(iii) reconstruct diet composition using a Bayesian stable-isotope mixing model (MixSIAR).

This dataset constitutes the longest isotopic time series assembled for this species in Terre Adelie (East Antarctica).

Further details on the data are presented in the Read_Me.