Marine Biology

, Volume 141, Issue 2, pp 263–269

Long-term trends in the Australasian gannet (Morus serrator) population in Australia: the effect of climate change and commercial fisheries

  •  A. Bunce
  •  F. Norman
  •  N. Brothers
  •  R. Gales

DOI: 10.1007/s00227-002-0838-1

Cite this article as:
Bunce, A., Norman, F., Brothers, N. et al. Marine Biology (2002) 141: 263. doi:10.1007/s00227-002-0838-1

Abstract.

The Australasian gannet (Morus serrator) population has increased considerably over the past century, both in New Zealand and Australia. Since 1980, the population in Australian waters has increased threefold, from 6,600 breeding pairs to approximately 20,000 pairs in 1999–2000, a rate of 6% per year. Reasons for the increase in the Australasian gannet population are poorly understood; here we consider the possible effects of recent fluctuations in climatic and oceanographic conditions, and changes in major local commercial fisheries. A significant trend towards more frequent, and stronger, El Niño Southern Oscillation events, warmer summer sea surface temperatures in Bass Strait, increased annual catches and catch per unit effort in the Victorian pilchard (Sardinops sagax) fishery and potential increased discarding of fisheries bycatch may account for at least some of the observed increase in the Australasian gannet population. The potential interactive effects of these factors on prey distribution and abundance and consequently on gannet numbers are discussed.

Copyright information

© Springer-Verlag 2002

Authors and Affiliations

  •  A. Bunce
    • 1
  •  F. Norman
    • 2
  •  N. Brothers
    • 3
  •  R. Gales
    • 3
  1. 1.Department of Zoology, University of Melbourne, Victoria 3010, Australia
  2. 2.Arthur Rylah Institute for Environmental Research, Department of Natural Resources and Environment, 123 Brown Street, Heidelberg, Victoria 3084, Australia
  3. 3.Tasmanian Parks and Wildlife Service, P.O. Box 44A, Hobart, Tasmania 7000, Australia
  4. 4.Present address: School of Ecology and Environment, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia