Marine alien species of South Africa — status and impacts

  • T B Robinson Centre for Invasion Biology, Zoology Department and Marine Biology Research Institute, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
  • C L Griffiths Centre for Invasion Biology, Zoology Department and Marine Biology Research Institute, University of Cape Town, Private Bag, Rondebosch 7701, South Africa
  • C D McQuaid Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
  • M Rius Department of Zoology and Entomology, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
Keywords: <i>Carcinus maenas</i>, <i>Crassostrea gigas</i>, marine alien species, <i>Mytilus galloprovincialis</i>

Abstract

The current status of marine alien species along the South African coast is reviewed and the ecological and economic impacts of these invasions are discussed. In all, 10 confirmed extant alien and 22 cryptogenic species are recorded from the region. All 10 alien species support well-established populations and the majority of these remain restricted in distribution to sheltered bays, estuaries and harbours. Only one species, the Mediterranean mussel Mytilus galloprovincialis, has spread extensively along the coast and caused significant ecological impacts. These include the competitive displacement of indigenous species and a dramatic increase in intertidal mussel biomass. These changes have also increased available habitat for many infaunal species and resulted in enhanced food supply for intertidal predators. Considerable economic benefits have also resulted from this invasion because M. galloprovincialis forms the basis of the South African mussel culture industry.

African Journal of Marine Science 2005, 27(1): 297–306
Published
2005-06-30
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X