Radiocarbon as a novel tracer of extra-Antarctic feeding in Southern Hemisphere humpback whales

Pascale Eisenmann*, Brian Fry, Debashish Mazumder, Geraldine Jacobsen, Carlysle Sian Holyoake, Douglas Coughran, Susan Bengtson Nash

*Corresponding author for this work

Research output: Contribution to journalArticle

8 Citations (Scopus)
1 Downloads (Pure)

Abstract

Bulk stable isotope analysis provides information regarding food web interactions, and has been applied to several cetacean species for the study of migration ecology. One limitation in bulk stable isotope analysis arises when a species, such as Southern hemisphere humpback whales, utilises geographically distinct food webs with differing isotopic baselines. Migrations to areas with different baselines can result in isotopic changes that mimic changes in feeding relations, leading to ambiguous food web interpretations. Here, we demonstrate the novel application of radiocarbon measurement for the resolution of such ambiguities. Radiocarbon was measured in baleen plates from humpback whales stranded in Australia between 2007 and 2013, and in skin samples collected in Australia and Antarctica from stranded and free-ranging animals. Radiocarbon measurements showed lower values for Southern Ocean feeding than for extra-Antarctic feeding in Australian waters. While the whales mostly relied on Antarctic-derived energy stores during their annual migration, there was some evidence of feeding within temperate zone waters in some individuals. This work, to our knowledge, provides the first definitive biochemical evidence for supplementary feeding by southern hemisphere humpback whales within temperate waters during migration. Further, the work contributes a powerful new tool (radiocarbon) for tracing source regions and geographical feeding.

Original languageEnglish
Article number4366
Pages (from-to)1-9
Number of pages9
JournalScientific Reports
Volume7
Issue number1
DOIs
Publication statusPublished - 29 Jun 2017
Externally publishedYes

Fingerprint Dive into the research topics of 'Radiocarbon as a novel tracer of extra-Antarctic feeding in Southern Hemisphere humpback whales'. Together they form a unique fingerprint.

  • Cite this

    Eisenmann, P., Fry, B., Mazumder, D., Jacobsen, G., Holyoake, C. S., Coughran, D., & Nash, S. B. (2017). Radiocarbon as a novel tracer of extra-Antarctic feeding in Southern Hemisphere humpback whales. Scientific Reports, 7(1), 1-9. [4366]. https://doi.org/10.1038/s41598-017-04698-2