Perspectives in Southern Hemisphere Limnology

Developments in Hydrobiology 28

Series editor H. J. Dumont

Perspectives in Southern Hemisphere Limnology

Proceedings of a Symposium, held in Wilderness, South Africa, July 3-13,1984

Edited by B. R. Davies and R. D. Walmsley

Reprinted from Hydrobiologia, vol. 125 (1985)

1985 DR W. JUNK PUBLISHERS A MEMBER OF THE KLUWER ACADEMIC PUBLISHERS GROUP

DORDRECHT/BOSTON/LANCASTER • "

Distributors

for the United States and Canada: Kluwer Boston, Inc., 190 Old Derby Street, Hingham, MA 02043, USA for the UK and Ireland: Kluwer Academic Publishers, MTP Press Limited, Falcon House, Queen Square, Lancaster LAI IRN, UK for all other countries: Kluwer Academic Publishers Group, Distribution Center, P.O. Box 322, 3300 AH Dordrecht, The Netherlands

Library of Congress Cataloging in Publication Data

Symposium on Perspectives in Southern Hemisphere Limnology (1984 : Wilderness, South Africa) Perspectives in Southern Hemisphere limnology.

(Developments in hydrobiology ; 28) 1. Limnology--Congresses. I. Davies, B. R. (Bryan

Robert) II. Walmsley, R. D. III. Title. IV. Title: Southern hemisphere limnology. V. Series. QE96.A3S954 1984 574.5'2G322 05-97G3

ISBN-13: 978-94-010-8937-1 DOl: 10.1007/978-94-009-5522-6

Cover design: Max Velthuijs

Copyright

e-ISBN-13: 978-94-009-5522-6

© 1985 Dr W. Junk Publishers, Dordrecht. Softcover reprint of the hardcover I st edition 1985

All rights reserved. No part of this publication may be re­produced, stored in a retrieval system, or transmitted in any form of by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publishers. Dr W. Junk Publishers, P.O. Box 163, 3300 AD Dordrecht, The Netherlands.

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The 'summarized continent' (modified from Troll, 1968), illustrating the unequal distribution of land-masses between the Northern and Southern Hemispheres.

Preface

This book contains the Proceedings of the Symposium on Perspectives in Southern Hemisphere Limnology which was held from 3-13 July 1984 in Wilderness, South Africa. It can be asked why this Symposium was necessary at a time when conferences, symposia and other gatherings of learned people abound. Limnologists in the Southern Hemisphere have for some time been pointing out that limnological theory and inland water management practices have been developed almost exclusively in Northern Hemisphere temperate latitudes. Most of the land masses of the Southern Hemisphere fall within lower latitudes, from 20-40 0 S, where the climate tends to be dry, with low cloud cover and with high levels of incident radiation and high water temperatures. Wide extremes are experienced in both rainfall and runoff, which occur mainly in summer. Sedimentary geological structures give rise to dispersive soils and highly turbid waters. Physiological, behavioural or developmental adaptations in the floral and faunal components are necessary to cope with desiccation and low visibility.

All these characters differ significantly from those of Northern Hemisphere inland waters. The rapid development and enormous human population pressures and needs in large areas of the Southern Hemis­phere and the consequent demands on limited water resources require wise planning and management policies. As a consequence, concepts and perspectives developed in the Northern Hemisphere must be carefully evaluated before being implemented in the management of water resources in the Southern Hemisphere. The conclusions reached by the Symposium participants are now available, hopefully to contribute to improved understanding and management of inland water resources in the Southern Hemis­phere.

D. F. Toerien Chairman: organizing committee

Sponsors

The following companies and organizations as­sisted the Organizing Committee through sponsor­ship:

Anglo American Chairman's Fund Barlow Rand Ltd B P Southern Africa Pty Ltd F ederale V olks Beleggings Bpk Gencor Development Fund National Parks Board Pretoria Portland Cement Co. Ltd Rhodes University SANLAM SASOL Ltd South African Airways South African Breweries South African Nature Foundation South African Water Research Commission University of the Orange Free State

Their involvement in the Symposium is gratefully acknowledged.

Contents

Preface .................................................................................................................. " ....... . VII

Acknowledgement: List of sponsors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. VIII

List of Participants ..................................................................... XI

1. Introduction: Perspectives in Southern Hemisphere limnology by B. R. Davies & R. D. Walmsley ................................................... .

SESSION A: THERMAL CHARACTERISTICS

2. Thermal characteristics of standing waters: An illustration of dynamic processes by 1. Imberger ..................................................................... 7

3. Thermal characteristics of running waters by 1. V. Ward...................................................................... 31

4. Thermal stability and phytoplankton distribution by A. B. Viner ..................................................................... 47

5. Thermal characteristics: Chairman's summary by B. R. Allanson .................................................................. 71

SESSION B: ARIDITY AND HYDROLOGICAL CHARACTERISTICS

6. Hydrology of low latitude Southern Hemisphere landmasses by W. 1. R. Alexander .............................................................. 75

7. Biotic adaptations in temporary lentic waters, with special reference to those in semi-arid and arid regions by W. D. Williams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

8. A review of the ecological effects of river regulation in Australia by K. F. Walker .................................................................... III

9. Aridity and hydrological characteristics: Chairman's summary by E. Braune.................................. . ........................... ......... 131

SESSION C: SEASONALITY-ASEASONALITY

10. Seasonality / aseasonality of aquatic macrophytes in Southern Hemisphere inland waters by D. S. Mitchell & K. H. Rogers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

II. Seasonality of aquatic invertebrates in low-latitude and Southern Hemisphere inland waters by R. C. Hart................................................................ ...... 151

12. Seasonality in Southern Hemisphere freshwater phytoplankton assemblages by P. J. Ashton .................................................................... 179

13. Seasonality/ aseasonality: Chairman's summary by F. M. Chutter ................................................................... 191

x

SESSION D: SUSPENSOIDS AND TURBIDITY

14. Effects of suspensoids (turbidity) on penetration of solar radiation in aquatic ecosystems by J. T. O. Kirk .................................................................... 195

15. Interactions of detrital particulates and plankton by J. M. Melack .. .. .. .. . .. .. . .. .. . . .. . . . .. . .. . . . . . .. .. .. .. . . . . . .. . .. . .. .. .. . . . . . . .. 209

16. The effects of suspensoids on fish by M. N. Bruton ................................................................... 221

17. Suspensoids and turbidity: Chairman's summary by C. Howard-Williams ............................................................. 243

Index of Organisms .................................................................... 247

Systems Index 251

Subject Index 255

List of participants

Mr E. G. J. Akhurst Department of Botany University of Natal P.O. Box 375 Pietermaritzburg 3200 South Africa

Mr W. 1. R. Alex,ander Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Professor B. R. Allanson Department of Zoology Rhodes University P.O. Box 94 Grahamstown 6140 South Africa

Mr C. G. M. Archibald NIWR: CSIR P.O. Box 395 Pretoria 0001 South Africa

Dr P. J. Ashton NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Ms S. Bethune Department of Water Affairs P.O. Box 2388 Windhoek 9000 Namibia

Professor D. N. Boshoff Department of Botany University of Zululand Private Bag K wadlangezwa 3886 South Africa

Mr H. H. Bosman Hydrological Research Institute Private Bag X313 Pretoria 000 I South Africa

Mr E. Braune Department of Water Affairs Private Bag X313 Pretoria 000 I South Africa

Professor C. M. Breen Department of Botany University of Natal P.O. Box 375 Pietermaritzburg 3200 South Africa

Professor M. N. Bruton J. L. B. Smith Institute for Ichthyology Private Bag 1015 Grahamstown 6140 South Africa

Mr C. A. Bruwer Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Ms B. Byren Zoology Department University of Cape Town Rondebosch 7700 South Africa

Mr J. A. Cambray Albany Museum Somerset Street Grahamstown 6140 South Africa

Dr F. M. Chutter NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Mr K. L. Cochrane NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Mrs S. A. Craddock Hydrological Research Institute Private Bag X313 Pretoria 000 I South Africa

Mr P. Cullen School of Applied Science Canberra College of Advanced Education P.O. Box I Belconnen ACT, Australia 2616

DrJ. A. Day Department of Zoology University of Cape Town Rondebosch 7'700 South Africa

Dr B. R. Davies Department of Zoology University of Cape Town Rondebosch 7700 South Africa

Dr F. C. de Moor Albany Museum Somerset Street Grahamstown 6140 South Africa

XII

Mr J. S. De Wet Hydrological Research Institute Private Bag X313 Pretoria 000 I South Africa

Mr W. G. Dorgeloh 203 Ramblers View Kellner Street Bloemfontein 9301 South Africa

Prof. F. de A. Esteves Botany Department University of Siio Carlos Via Washington Luiz km 235 13560 Siio Carlos SP Brazil

Mr B. Faulkner Hydrological Research Institute Private Bag X313 Pretoria 000 I South Africa

Mr W. D. M. Fourie Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Professor I. G. Gaigher Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mr A. J. C. Gardiner Department of Zoology University of Cape Town Rondebosch 7700 South Africa

Mrs S. Grindley School of Environmental Studies University of Cape Town Rondebosch 7700 South Africa

Professor J. U. Grobbelaar Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mr D. C. Grobler Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Dr K. C. D. Hamman J onkershoek Fisheries Research Station Private Bag X5014 Stellenbosch 7600 South Africa

Professor R. C. Hart Institute for Freshwater Studies Rhodes University P.O. Box 94 Grahamstown 6140 South Africa

Mrs A. Hanekom Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Professor J. Heeg Department of Zoology University of Natal P.O. Box 375 Pietermaritzburg 3200 South Africa

Mr J. R. Hely-Hutchinson NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Dr C. Howard-Williams DSIR (Freshwater Section) P.O. Box 415 Taupo New Zealand

Miss A. H. Howman Hydrological Research Institute Department of Environment Affairs Private Bag X3 I3 Pretoria 000 I South Africa

Mr M. R. Howard Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Mr B. J. Huntley FRD: CSIR P.O. Box 395 Pretoria 000 I South Africa

Professor J. Imberger Director: Centre for Environmental Fluid Dynamics University of Western Australia Nedlands W A. Australia 6009

Mr A. C. Jarvis NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Mr J. H. B. Joubert P.O. Box 2923 Bloemfontein 9300 South Africa

Professor P. C. Keulder P.O. Box 754 Harrismith 9880 South Africa

DrJ. M. King Department of Zoology University of Cape Town Rondebosch 7700 South Africa

Dr J. T. O. Kirk Division of Plant Industry P.O. Box 1600 Canberra City ACT. Australia 2601

Mr B. Leu Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mr M. Luther Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Dr R. J. MacDonald State Pollution Control Commission G.P.O. Box 4036 Sydney Australia 2001

Mr B. E. Marshall Lake Kariba Fisheries Institute P.O. Box 75 Kariba Zimbabwe

Dr J. M. Melack Department of Biological Sciences University of California Santa Barbara, CA 93106 U.S.A.

Dr D. S. Mitchell Division of Irrigation Research CSIRO Private Bag Griffith NSW, Australia 2680

Mr S. A. Mitchell Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mr T. N. Mqolomba Department of Zoology University of the Transkei Private Bag X5092 Umtata Transkei

Dr R. G. Noble FRD: CSIR P.O. Box 395 Pretoria 000 I South Africa

Dr J. H. O'Keeffe Institute for Freshwater Studies Rhodes University P.O. Box 94 Grahamstown 6140 South Africa

Dr J. C. Patterson Department of Civil Engineering University of Western Australia Nedlands W A, Australia 6009

Miss J. Pearce University of Natal P.O. Box 409 Hillcrest 3650 South Africa

Professor A. J. H. Pieterse Department of Botany University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Dr A. J. Ribbink J.L.B. Smith Institute for Ichthyology Private Bag 1015 Grahamstown 6140 South Africa

Miss D. Richardson Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Dr R. D. Robarts NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Dr K. H. Rogers

Department of Botany University of the Witwatersrand P.O. Box 1176 Johannesburg 2000 South Africa

Miss K. I. Roos Institute for Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mrs L. Rossouw Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Mr D. P. Sartory Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Mr C. H. G. Schlettwein Department of Water Affairs Private Bag 13193 Windhoek 9000 Namibia

Mr W. E. Scott NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Mr. M. T. Seaman Department of Zoology University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Mr M. J. Silberbauer Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Dr P. H. Skelton

XIII

J .L.B. Smith Institute for Ichthyology Private Bag 1015 Grahamstown 6140 South Africa

Mr V. R. Smith Department of Environmental Sciences University of the Orange Free State P.O. Box 339 Bloemfontein 9300 South Africa

Miss M. Steenkamp Roqueford 603 Kellner Street Bloemfontein 9300 South Africa

Ms B. A. Stewart Department of Zoology University of Cape Town Rondebosch 7700 South Africa

Mr M. Steyn S. A. Water Information Centre P.O. Box 395 Pretoria 0001 South Africa

Mr M. C. Steynberg Rand Water Board P.O. Box 1127 Johannesburg 2000 South Africa

XIV

Mr S. Sym 133 Standard Drive Blairgowrie Randburg South Africa

Dr J. A. Thornton NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Dr D. F. Toerien NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Dr A. J. Twinch NIWR: CSIR P.O. Box 395 Pretoria 000 I South Africa

Mrs C. E. Van Ginkel Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Dr H. R. Van Vliet Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa

Dr A. B. Viner DSIR (Freshwater Section) P.O. Box 415 Taupo New Zealand

Dr K. F. Walker Department of Zoology University of Adelaide Box 498 Adelaide SA, Australia 5001

Dr R. D. Walmsley Department of Plant Sciences Rhodes University P.O. Box 94 Grahamstown 6140 South Africa

Professor J. V. Ward Department of Zoology and Entomology Colorado State University Fort Collins, CO.80523 U.S.A.

Dr A. K. Whitfield Swartvlei Research Project P.O. Box 49 Sedgefield 6563 South Africa

Professor W. D. Williams Department of Zoology University of Adelaide Box 498 Adelaide SA, Australia 5001

Mrs S. G. Young Hydrological Research Institute Department of Environment Affairs Private Bag X313 Pretoria 000 I South Africa