Polar Biology

, Volume 38, Issue 8, pp 1195–1202

From sea ice to blubber: linking whale condition to krill abundance using historical whaling records

  • Janelle E. Braithwaite
  • Jessica J. Meeuwig
  • Tom B. Letessier
  • K. Curt S. Jenner
  • Andrew S. Brierley
Original Paper

DOI: 10.1007/s00300-015-1685-0

Cite this article as:
Braithwaite, J.E., Meeuwig, J.J., Letessier, T.B. et al. Polar Biol (2015) 38: 1195. doi:10.1007/s00300-015-1685-0

Abstract

Krill (Euphausia superba) are fundamentally important in the Southern Ocean ecosystem, forming a critical food web link between primary producers and top predators. Krill abundance fluctuates with oceanographic conditions, most notably variation in winter sea ice, and is susceptible to environmental change. Although links between local krill availability and performance of land breeding, central place foragers are recognised, the effects of krill variability on baleen whales remain largely unclear because concurrent long-term data on whale condition and krill abundance do not exist. Here, we quantify links between whale body condition and krill abundance using a simple model that links krill abundance to sea ice extent. Body condition of humpback whales (Megaptera novaeangliae) caught in west Australian waters between 1947 and 1963 was estimated from oil yields in whaling records. Annual estimates of krill abundance in the Southern Ocean where those whales foraged (70°–130°E) were correlated significantly with contemporary annual winter sea ice extent. We hindcast sea ice extent for the whaling period from reconstructed temperature data and found that whale body condition was significantly correlated with hindcasted winter sea ice extent, supporting the hypothesis that variations in body condition were likely mediated by associated krill fluctuations. As humpback whales migrate and breed on finite energy stores accrued during summer foraging in the Antarctic, changes in sea ice and concomitant changes in krill abundance have long-term implications for their condition and reproductive success.

Keywords

Euphausia superba Humpback whale Megaptera novaeangliae Sea ice dynamics Energetics Migration 

Supplementary material

300_2015_1685_MOESM1_ESM.docx (124 kb)
Supplementary material 1 (DOCX 123 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Janelle E. Braithwaite
    • 1
  • Jessica J. Meeuwig
    • 1
    • 2
  • Tom B. Letessier
    • 2
  • K. Curt S. Jenner
    • 3
  • Andrew S. Brierley
    • 4
  1. 1.School of Animal Biology (UWA Oceans Institute), Faculty of ScienceUniversity of Western AustraliaCrawleyAustralia
  2. 2.The Centre for Marine Futures (UWA Oceans Institute), Faculty of ScienceUniversity of Western AustraliaCrawleyAustralia
  3. 3.Centre for Whale ResearchFremantleAustralia
  4. 4.Pelagic Ecology Research Group, Scottish Oceans InstituteUniversity of St AndrewsSt AndrewsUK