Nile tilapia invades the Lake Malawi catchment

  • MJ Genner
  • E Connell
  • A Shechonge
  • A Smith
  • J Swanstrom
  • S Mzighani
  • A Mwijage
  • BP Ngatunga
  • GF Turner

Abstract

The Lake Malawi/Nyasa catchment contains over 835 endemic cichlid fish species. This unique biodiversity has made it widely recognised as one of the world’s most significant freshwater ecosystems. Here we report the first occurrence records of two invasive tilapiines, Oreochromis niloticus and Oreochromis leucostictus, inside the Lake Malawi catchment. The introductions took place during initiatives to develop aquaculture and new capture fisheries. Oreochromis niloticus is an important competitor and predator of native species, has potential to hybridise with indigenous Oreochromis species, and has been widely implicated in biodiversity loss globally. It was a key contributor to the destruction of the Lake Victoria indigenous Oreochromis fishery. In light of apparent risks to unique biodiversity, and in the absence of robust evidence that introductions will bring enhanced socio-economic benefits over indigenous species, it is advisable that efforts be made to eradicate invasive species. The precautionary principle holds that future fisheries and aquaculture development in the region should be based exclusively on non-invasive indigenous species.

Keywords: alien species, aquaculture development, fisheries development, hybridisation, species loss

African Journal of Aquatic Science 2013, 38(Suppl.): 85–90

Author Biographies

MJ Genner
School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
E Connell
School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
A Shechonge
School of Biological Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
A Smith
Department of Biological Sciences, University of Hull, Cottingham Road, Kingston-upon-Hull, HU6 7RX, UK
J Swanstrom
School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG, UK
S Mzighani
Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar-es-Salaam, Tanzania
A Mwijage
Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar-es-Salaam, Tanzania
BP Ngatunga
Tanzania Fisheries Research Institute (TAFIRI), PO Box 9750, Dar-es-Salaam, Tanzania
GF Turner
School of Biological Sciences, Bangor University, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
Published
2013-11-07
Section
Articles

Journal Identifiers


eISSN: 1727-9364
print ISSN: 1608-5914