Polar Biology

, Volume 31, Issue 12, pp 1509–1520

Decline in energy storage in the Antarctic minke whale (Balaenoptera bonaerensis) in the Southern Ocean

  • Kenji Konishi
  • Tsutomu Tamura
  • Ryoko Zenitani
  • Takeharu Bando
  • Hidehiro Kato
  • Lars Walløe
Original Paper

DOI: 10.1007/s00300-008-0491-3

Cite this article as:
Konishi, K., Tamura, T., Zenitani, R. et al. Polar Biol (2008) 31: 1509. doi:10.1007/s00300-008-0491-3

Abstract

The annual trend in energy storage in the Antarctic minke whale was examined using catch data from all 18 survey years in the Japanese Whale Research Program (JARPA). Regression analyses clearly showed that blubber thickness, girth and fat weight have been decreasing for nearly 2 decades. The decrease per year is estimated at approximately 0.02 cm for mid-lateral blubber thickness and 17 kg for fat weight, corresponding to 9% for both measurements over the 18-year period. Furthermore, “date”, “extent of diatom adhesion”, “sex”, “body length”, “fetus length”, “latitude”, “age” and “longitude” were all identified as partially independent predictors of blubber thickness. The direct interpretation of this substantial decline in energy storage in terms of food availability is difficult, since no long-term krill abundance series is available. However, an increase in the abundance of krill feeders other than minke whales and a resulting decrease in the krill population must be considered as a likely explanation.

Keywords

AntarcticaMinke whaleBalaenoptera bonaerensisLong-term changeEuphausia superbaPrey availability

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Kenji Konishi
    • 1
  • Tsutomu Tamura
    • 1
  • Ryoko Zenitani
    • 1
  • Takeharu Bando
    • 1
  • Hidehiro Kato
    • 2
  • Lars Walløe
    • 3
  1. 1.Institute of Cetacean ResearchTokyoJapan
  2. 2.Tokyo University of Marine Science and TechnologyTokyoJapan
  3. 3.Department of Physiology, Institute of Basic Medical SciencesUniversity of OsloOsloNorway