Figure 5. Mean δ¹³C and δ¹⁵N values of sub-yearling elephant seals and other Southern Ocean marine organisms.

Mean δ¹³C and δ¹⁵N values in the whiskers of individual sub-yearlings foraging in ACC to PF-S (blue symbols) and PF (green symbols) zones, corrected for trophic discrimination by subtracting 3.2‰ and 2.8‰ from δ¹³C and δ¹⁵N values in Fig. 4B, respectively. Mean δ¹³C and δ¹⁵N values in the tissues of other Southern Ocean marine organisms ([69], [70], [71], [72], this study) were grouped into crustacean, fish and squid taxa (white, dark grey and grey symbols, respectively). E.frig: Euphausia frigida; E.sup: E. superba; E.tria: E. triacantha; Them: Themisto gaudichaudii; E.ant: Electrona antarctica; E.ant (Kerg.): Electrona antarctica (Kerguelen); G.fra: Gymnoscopelus fraseri; G.nic: G. nicholsi; G.pia: G. piablis; Kreff.: Krefftichthys anderssoni; P.ten: Protomyctophum tenisoni; B.aby: Bathyteuthis abysicola; Hist.: Histioteuthis eltaninae; Kond.: Kondakovia longimana; Psych.: Psychroteuthis glacialis; Psych. (RS): Psychroteuthis glacialis (Ross Sea); G.gla: Galiteuthis glacialis; Mart.: Martialia hyadesi. Squid beak values were corrected for the reduced ¹⁵N enrichment due to chitin. Values are mean±SD.