POPULATION ANALYSES OF INDO-PACIFIC HUMPBACK DOLPHINS SOUSA CHINENSIS IN ALGOA BAY, EASTERN CAPE, SOUTH AFRICA1

Authors

  • Leszek Karczmarski,

    1. Centre for Dolphin Studies, Port Elizabeth Museum, P. O. Box 13147, Humewood 6013, South Africa
    2. Department of Zoology, University of Port Elizabeth, P. O. Box 1600, Port Elizabeth 6000, South Africa E-mail: karczmal@tamug.tamu.edu
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    • 2

      Present address: Marine Mammal Research Program, Texas A&M University at Galveston, 4700 Ave. U, Bldg. 303, Galveston, TX 77551, U. S. A. and Oceanic Society, Midway Spinner Dolphin Research Project, Midway Island Station # 2, P. O. Box 29460, Honolulu, HI 96820-1860, U. S. A.

  • Paul E. D. Winter,

    1. Department of Zoology, University of Port Elizabeth, P. O. Box 1600, Port Elizabeth 6000, South Africa
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  • Victor G. Cockcroft,

    1. Centre for Dolphin Studies, Port Elizabeth Museum, P. O. Box 13147, Humewood 6013, South Africa
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    • 3

      Present address: Centre for Dolphin Studies, P. O. Box 1856, Plettenberg Bay 6600, South Africa.

  • Anton Mclachlan

    1. Department of Zoology, University of Port Elizabeth, P. O. Box 1600, Port Elizabeth 6000, South Africa
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    • 4

      Present address: College of Science, SQU, P. O. Box 36, SQU 123, Oman.


  • 1

    This work is dedicated to the memory of Kenneth Norris, whose lifelong desire to understand the natural world and that of cetaceans in particular, inspired a continuing scientific curiosity and a sense of wonder in many, myself included.–Leszek Karczmarski

  • Ken, your recognition, enthusiasm, and encouragement gave enormous impetus to work in Africa. I hope that we can foster and nurture the next generation of interest the way you did ours.–Vic Cockcroft

Abstract

Mark-recapture analyses were performed on photo-identification data for Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Algoa Bay, on the Eastern Cape coast of South Africa. Boat-based photo-ID surveys were undertaken between May 1991 and May 1994. The rate of discovery of newly identified dolphins, distribution of sightings and frequency of resightings of known individuals indicate a high level of seasonal immigration of humpback dolphins into, and emigration from, the Algoa Bay region in summer. Consequently, humpback dolphins from Algoa Bay appear to be part of a substantially larger population that uses a considerable length of the coastal zone. The minimum population size is estimated to be about 466 dolphins.

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