Temporal shift in the isotopic niche of female Antarctic fur seals from Bouvetøya

Polar research

Arnaud Tarroux¹ 

[1] Norwegian Polar Institute, Fram Centre, PO Box 6606 Langnes, NO-9296 Tromsø, NorwayCorrespondence

关键词: Arctocephalus gazella;    krill;    predation;    Southern Ocean;    stable isotopes;    trophic relationships.;   

DOI  :  10.3402/polar.v35.31335

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

The Antarctic fur seal (Arctocephalus gazella) is a key marine predator in the Southern Ocean, a region that has recently started to show changes as a result of global climate change. Here, carbon (δ13C) and nitrogen (δ15N) stable isotope analyses on whole blood and plasma samples were used to examine the isotopic niche of lactating female Antarctic fur seals. Using recently developed Bayesian approaches to determine changes in isotopic niche, a significant increase in δ13C and δ15N was found between 1997 and 2015; this change occurred at an average rate of 0.067‰ (δ13C) and 0.072‰ (δ15N) per year over this period. This suggests that a marked isotopic niche shift has occurred over this period, which very likely corresponds to a shift in diet towards prey at a higher trophic level, such as fish (replacing krill). Although our sampling design prevented us from exploring a seasonal trend in a conclusive manner, our data suggest that concurrent increases in δ13C and δ15N might occur as the breeding season pro...

【 授权许可】

CC BY-NC