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Author Oyugi, Dalmas Oyugi ♦ Harper, David Matthew ♦ Ntiba, Japheth Michemi ♦ Kisia, Seth Marande ♦ Britton, John Robert
Source SpringerLink
Content type Text
Publisher Springer Netherlands
File Format PDF
Copyright Year ©2011
Language English
Subject Domain (in DDC) Social sciences ♦ Public administration & military science ♦ Administration of economy & environment
Subject Keyword Oreochromis leucostictus ♦ Tilapia zillii ♦ Catch per unit effort ♦ Fishery catch ♦ Environmental change ♦ Physical Geography ♦ Meteorology/Climatology ♦ Ecology ♦ Environment ♦ Environmental Engineering/Biotechnology ♦ Environmental Management
Abstract The tilapiine cichlids Oreochromis leucostictus and Tilapia zillii were introduced into Lake Naivasha, Kenya, in 1956. Previous studies on data collected to 1987 revealed they were persistent following establishment, despite environmental variability and exploitation. Recent data, however, suggest this persistence is under threat as data indicate some significant declines in aspects of their abundance since 1999. The influence of changes in lake level, allodiversity and fishing effort on this decline was tested and showed that a decline in lake level was a significant causal factor. The recent change in allodiversity, with the establishment and dominance of Cyprinus carpio in the fishery, was not significant on the catch per unit effort of O. leucostictus but was on T. zillii. Since 1999, catches of tilapiines in the fishery have been independent of fishing effort, contrary to between 1975 and 1987, suggesting their management through application of fishery models may no longer be applicable. As it was anthropogenic-mediated lake level changes that were mainly responsible for their decline, then lake management should focus on sustainable water utilization that maximizes lake levels in accordance with the basin-wide water balance.
ISSN 00447447
Age Range 18 to 22 years ♦ above 22 year
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2011-02-16
Publisher Place Dordrecht
e-ISSN 16547209
Journal AMBIO
Volume Number 40
Issue Number 5
Page Count 10
Starting Page 469
Ending Page 478


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Source: SpringerLink