Procambarus clarkii in Lake Naivasha, Kenya, and its effects on established and potential fisheries

• Published in: Aquaculture Vol. 11; no. 2; pp. 111 - 121
• Main Authors: Lowery, R.S., Mendes, A.J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.1977
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/0044-8486(77)90069-2

P. clarkii was introduced into Lake Naivasha in about 1970 since when it has multiplied and now forms an important organism in the eastern basin. It breeds throughout the year but with a distinct peak being obvious at such times as when the water level increases, which it does erratically. The increase in distribution and numbers from 1974–1976 is recorded; this will obviously continue as there are ample areas which it does not occupy at present. The density of population in the eastern basin is between one and three individuals of marketable size per square metre. The quality of tail meat was surveyed because of the fishery potential of the species. In some parts of the littoral region of the lake many animals were found to have atrophied muscles in the tail; it is suggested that this may in part be due to dietary deficiency. P. clarkii has been introduced into the catchment areas of three major Kenyan rivers, including the Nzoia River draining to Lake Victoria. The implications of this for established gill net fisheries are discussed in the light of experience at Lake Naivasha where the species is a nuisance.