Research Papers

Nile tilapia invades the Lake Malawi catchment

DOI: 10.2989/16085914.2013.842157
Author(s): MJ GennerSchool of Biological Sciences, UK, E ConnellSchool of Biological Sciences, UK, A ShechongeSchool of Biological Sciences, UK, A SmithDepartment of Biological Sciences, UK, J SwanstromSchool of Biological Sciences, UK, S MzighaniTanzania Fisheries Research Institute (TAFIRI), Tanzania, A MwijageTanzania Fisheries Research Institute (TAFIRI), Tanzania, BP NgatungaTanzania Fisheries Research Institute (TAFIRI), Tanzania, GF TurnerSchool of Biological Sciences, UK

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.

Get new issue alerts for African Journal of Aquatic Science