Preliminary indications of climate-induced change in a warm-temperate South African estuarine fish community

Authors

  • N. C. James,

    Corresponding author
    1. * South African Environmental Observation Network, Private Bag 1015, Grahamstown 6140, South Africa and South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa
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  • A. K. Whitfield,

    1. * South African Environmental Observation Network, Private Bag 1015, Grahamstown 6140, South Africa and South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa
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  • P. D. Cowley

    1. * South African Environmental Observation Network, Private Bag 1015, Grahamstown 6140, South Africa and South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa
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†Tel.: +2746 6229899; fax: +2746 629899; email: nikkij@saeon.ac.za

Abstract

The fishes of the warm-temperate East Kleinemonde Estuary (South Africa) have been sampled bi-annually, in summer and winter, using seine and gillnets since December 1995 and a total of 19 families, represented by 38 species were recorded between December 1995 and July 2006. Indicative of a warming trend, six new species of tropical fishes (Valamugil cunnesius, Valamugil robustus, Liza alata, Liza macrolepis, Glossogobius giuris and Terapon jarbua) were recorded in the catches from 1999 onwards, with V. cunnesius and L. macrolepis recorded in catches almost every year after 2002. Mean annual sea-surface temperatures recorded along the adjacent coast have been increasing during the past decade and this may have facilitated the southward extension of tropical marine fishes into the warm-temperate biogeographic zone.

Ancillary