The Impact of Species Changes in African Lakes

609 Pages·1995·12.015 MB·English

by  Tony J. Pitcher (auth.), Tony J. Pitcher, Paul J. B. Hart (eds.)

The Impact of Species Changes
in African Lakes
CHAPMAN & HAIL FISH AND FISHERIES SERIES
Amongst the fishes, a remarkably wide range of fascinating biological
adaptations to diverse habitats has evolved. Moreover, fisheries are of
considerable importance in providing human food and economic benefits.
Rational exploitation and management of our global stocks of fishes must
rely upon a detailed and precise insight of the interaction of fish biology with
human activities.
The Chapman & Hall Fish and Fisheries Series aims to present authoritative
and timely reviews which focus on important and specific aspects of
the biology, ecology, taxonomy, physiology, behaviour, management and
conservation of fish and fisheries. Each volume will cover a wide but unified
field with themes in both pure and applied fish biology. Although volumes
will outline and put in perspective current research frontiers, the intention
is to provide a synthesis accessible and useful to both experts and non-specialists
alike. Consequently, most volumes will be of interest to a broad spectrum
of research workers in biology, zoology, ecology and physiology, with an
additional aim of the books encompassing themes accessible to non-specialist
readers, ranging from undergraduates and postgraduates to those with an
interest in industrial and commercial aspects of fish and fisheries.
Applied topics will enhance synopses of fishery issues which will appeal
to a wide audience of fishery scientists, aquaculturists, economists, geographers
and managers in the fishing industry. The series will also contain practical
guides to fishery and analysis methods and global reviews of particular types
of fisheries.
Books already published and forthcoming are listed below. The Publisher
and Series Editor would be glad to discuss ideas for new volumes in the series ...
Av aUable titles
1. Ecology of Teleost Fishes
Robert J. Wootton
2. Cichlid Fishes
Behaviour, ecology and evolution
Edited by Miles A. Keenlyside
3. Cyprinid Fishes
Systematics, biology and exploitation
Edited by Ian J. Winfield and Joseph S. Nelson
4. Early life History of Fish
An energetics approach
Ewa Kamler
5. Fisheries Acoustics
David N. MacLennan and E. John Simmonds
6. Fish Chemoreception
Edited by Toshiaki J. Hara
7. Behaviour of Teleost Fishes
Second edition
Edited by Tony J. Pitcher
8. Genetics and Fish Breeding
Colin R. Purdom
9. Fish Ecophysiology
J. Cliff Rankin and Frank B. Jensen
10. Fish Swimming
John J. Videler
11. On the Dynamics of Exploited Fish Populations
Raymond J .H. Beverton and Sidney J. Holt
(Facsimile reprint)
12. Sea Bass
Graham D. Pickett and Michael G. Pawson
13. Fish Bioenergetics
Malcolm Jobling
14. On the Sex of Fish and Gender of Scientists
Daniel Pauly
15. Hake
Fisheries, ecology and markets
Edited by Jiirgen Alheit and Tony J. Pitcher
16. Environmental Biology of Fishes
Malcolm Jobling
17. Electric Fishes
History and behavior
Peter Moller
18. The Impact of Species Change in African Lakes
Edited by Tony J. Pitcher and Paul B. Hart
19. Pike
Biology and exploitation
Edited by John F. Craig
20. Reef Fisheries
Edited by Nicholas V. C. Polunin and Callum M. Roberts
Forthcoming titles
Fisheries Ecology
Second edition
Edited by T.J. Pitcher and P. Hart
The Impact of
Species Changes in
African Lakes
Edited by
Tony J. Pitcher
Fisheries Centre
University of British Columbia
Vancouver
Canada
and
Paul J.B. Rart
Department of Zoology
Leicester University
Leicester
UK
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
First edition 1995
© 1995 Springer Science+Business Media Dordrecht
Originally published by Chapman & Hali in 1995
Softcover reprint of the hardcover I st edition 1995
Typeset in lOj12pt Photina by AFS Image Setters Ltd. Glasgow
ISBN 978-94-010-4249-9 ISBN 978-94-011-0563-7 (eBook)
DOI 10.1007/978-94-011-0563-7
Apart from any fair dealing for the purposes of research or private study. or criticism or review.
as permitted under the UK Copyright Designs and Patents Act. 1988. this publication may not
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to the publishers at the Glasgow address printed on this page.
The publisher makes no representation. express or implied. with regard to the accuracy of
the information contained in this book and cannot accept any legal responsibility or liability
for any errors or omissions that may be made.
A catalogue record for this book is available from the British Library
Library of Congress Catalog Card Number: 95-69068
~ Printed on permanent acid-free text paper. manufactured in accordance with ANSIjNISO
Z39.48-1992 and ANSIjNISO Z39.48-1984 (Permanence of Paper).
To the memory of Aggrey W. Kudhongania
Contents
List of contributors xix
Series foreword Tony J. Pitcher xxiii
Preface Tony J. Pitcher and Paul J.B. Hart xxv
General introduction Paul J.B. Hart xxvii
The impact of species changes in African lakes
References
1 Species changes and fisheries in Mrican lakes:
outline of the issues 1
Tony J. Pitcher
1.1 Introduction 1
1.2 Geographical scope of the book 2
1.3 Introduction of fish to Mrican lakes 5
1.4 Establishment of introduced species 6
1.5 Impacts of fish introductions 9
1.6 Ecological models of fish introductions 10
1.7 Evaluation of the impacts of species changes 10
1.8 Mitigation of the impacts of species changes 13
1.9 General recommendations for development and
assistance in Mrican lake fisheries 14
Acknowledgements 15
References 15
Part One Introduced Nile Perch in Lake Victoria:
Impacts on Biodiversity and Evaluation of the Fishery
2 Impact of environmental change, species introductions and
ecological interactions on the fish stocks of Lake Victoria 19
Aggrey W. Kudhonganiat and Deonatus B.R. Chitamwebwa
x Contents
2.1 Introduction 19
2.2 Impact of exploitation 20
2.3 Impact of competition and hybridization 23
2.4 Impact of environmental changes 24
2.5 Impact of predation by Lates 25
2.6 Exploitation versus predation by Lates 27
2.7 The new fishery of Lake Victoria 28
2.8 Summary 29
Acknowledgements 30
References 30
3 Limnological changes in Lake Victoria since the Nile perch
introduction 33
Peter B.a. Ochumbat
3.1 Introduction 33
3.2 Discussion 38
3.3 Conclusion 39
3.4 Summary 40
Acknowledgements 41
References 41
4 Impact of fish species introductions on the tilapias of
Lakes Victoria and Kyoga 45
Timothy Twongo
4.1 Introduction 45
4.2 Ecological considerations 46
4.3 How introduced species affect indigenous fishes 51
Acknowledgements 55
References 55
5 Diversity and stability of fish stocks in Lakes Victoria.
Kyoga and Nabugabo after establishment of introduced species 59
Richard Ogutu-Ohwayo
5.1 Introduction 59
5.2 Methods 60
5.3 Results 62
5.4 Discussion 76
5.5 Summary 79
Acknowledgements 79
References 80
Contents xi
6 Dynamics of the haplochromine cichlid fauna and other
ecological changes in the Mwanza Gulf of Lake Victoria 83
Frans Witte, Tijs Goldschmidt and Jan H. Wanink
6.1 Introduction 83
6.2 Distribution and increase of the Nile perch 85
6.3 Decline of the haplochromines 88
6.4 Dynamics in morphology and ecology of haplochromines 91
6.5 Observations on other fish stocks and other organisms 99
6.6 Summary 104
Acknowledgements 106
References 106
7 An analysis of species changes in Lake Victoria:
did the Nile perch act alone? 111
Alida Bundy and Tony J. Pitcher
7.1 Introduction 111
7.2 Methods 112
7.3 Results 117
7.4 Discussion 125
7.5 Conclusions 132
Acknowledgements 133
References 133
8 Analysis of species changes in Lake Victoria using ECOP ATH,
a multispecies trophic model 137
Jacques Moreau
8.1 Introduction 137
8.2 Lake Victoria: a severely damaged ecosystem 138
8.3 Material and methods 140
8.4 Results 148
8.5 Discussion 156
8.6 Conclusions 157
8.7 Summary 158
Acknowledgements 158
References 158
9 Assessment of the Nile perch fishery in Lake Victoria 163
Tony J. Pitcher and Alida Bundy
9.1 Introduction 163
9.2 Assembly of data 164
9.3 Analytical methods 167
9.4 Results 170
9.5 Discussion 175
9.6 Summary 179
xii Contents
Acknowledgements 179
References 179
10 Thirty years on: the development of the Nile perch fishery in
Lake Victoria 181
J. Eric Reynolds. Dominique F. Greboval and Piero Mannini
10.1 The making of an 'ichthyo-imbroglio' 181
10.2 Pre-perch. post-perch: the fisheries regimes compared 183
10.3 Impact assessment 199
10.4 Discussion: the outlook 205
10.5 Summary and conclusions 208
Acknowledgements 210
References 211
11 Socio-economic impacts of introduced species in Lake Victoria
fisheries 215
Craig K. Harris. David S. Wiley and Douglas C. Wilson
11.1 Introduction 215
11.2 Individual and household impacts 217
11.3 Community and organizational impacts 227
11.4 Impacts at the national level 231
11.5 International and transnational impacts 234
11.6 Summary 237
Acknowledgements 238
References 238
Part Two Evaluation of Species Changes in Other Mrican Lakes
with Introduced Fish Species
12 Inshore fish population and species changes in Lake Kariba.
Zimbabwe 245
Lawrence Karenge and Jeppe Kolding
12.1 Introduction 245
12.2 Background information 247
12.3 Brief history of the commercial fisheries 249
12.4 The experimental fishery 250
12.5 Changes in species composition 252
12.6 Trends in catch per unit effort 254
12.7 Discussion 263
12.8 Conclusion 270
12.9 Summary 271
Acknowledgements 272
References 272