Fisheries Management: a Manual for Still-Water Coarse Fisheries
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Fisheries Management Fisheries Management A Manual for Still-Water Coarse Fisheries Ash Girdler CBiol, FIBiol, MIFM, FIFM, CEnv Ian Wellby FIFM, CEnv Robin Welcomme PhD, HonFSE, FIFM, CEnv A John Wiley & Sons, Ltd., Publication This edition fi rst published 2010 © 2010 by Blackwell Publishing Ltd Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing programme has been merged with Wiley’s global Scientifi c, Technical, and Medical business to form Wiley-Blackwell. Registered offi ce John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom Editorial offi ces 9600 Garsington Road, Oxford, OX4 2DQ, United Kingdom 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offi ces, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell. The right of the author to be identifi ed as the author of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Girdler, Ashley. Fisheries management : a manual for still-water coarse fi sheries / Ashley Girdler, Ian Wellby, Robin Welcomme. – 1st ed. p. cm. Includes index. ISBN 978-1-4051-3332-6 (hardback : alk. paper) 1. Fishery management. I. Wellby, Ian. II. Welcomme, R. L. III. Title. SH328.G69 2010 639.3'12–dc22 2009038733 A catalogue record for this book is available from the British Library. Set in 10 on 12.5 pt Sabon by Toppan Best-set Premedia Limited Printed in Singapore 1 2010 Contents Acknowledgements vii Part I Ecology of Still-Water Fisheries 1 1 Introduction 3 2 Ecology of Lakes 5 3 Bacteria 25 4 Plants 28 5 Invertebrates 35 6 Fish 43 7 Disease-Causing Organisms 79 Chris Williams and Ian Wellby 8 Mammals and Birds 97 Part II Management of Still-Water Fisheries 103 9 Developing and Preparing a Fishery 105 10 The Construction of a Still-Water Fishery 122 11 Fish Stock Assessment 154 12 Stock Manipulation 170 13 Invertebrate Survey 196 14 Control of Water Quality 198 15 Control of Aquatic Plants 208 16 Control of Erosion 224 17 Control of Predators and Nuisance Species 236 18 Managing the Impact of Climate Change on Still-Water Fisheries 256 19 Control of Fish Disease 259 20 Biosecurity 270 21 Control of Fishing Activities 274 22 Fish Nutrition 285 23 Improving Conditions or Fishery Enhancement 306 24 General Administration 344 Part III Legal and Social Framework 357 25 General Legislation 359 26 Environmental Legislation 364 v vi Contents 27 Direct Fisheries-Related Legislation 368 28 Agencies and Organisations 373 Appendix A: Example of Risk Assessment 380 Appendix B: Example Model of a Disciplinary Procedure 383 Appendix C: Example of a Fisheries Survey 386 Glossary 393 Further Reading 395 Index 398 Acknowledgements We express our gratitude to Dr Chris Williams for his work on the fi sh health chapter and other help he has offered. We also thank Nigel Hewlett for his advice during the preparation of this book. Many thanks too to Jenny Wellby for the help and support she has offered and her contribution in editing the various drafts. We also thank the staff of the A.G.A. Group, who have contributed to this book by taking the time to extend their efforts during the working day to provide the expansion of our image library, which has ensured that the text is populated with up- to - date graphics and images. vii Part I Ecology of Still - Water Fisheries Before looking at the management of a still- water fi shery, it is important to understand how lake and pond ecosystems function in the absence of human interference. Still- waters are fascinating and complex aquatic environments that are very different from the terrestrial environment in which we live. It is important to acknowledge and understand these differ- ences so that we fully understand the possible consequences of any management decisions. Although we describe our still- waters as freshwater lakes, suggesting that the water is in some way pure water, in reality it is never pure. Even rain is not pure water as it contains signifi cant amounts of dissolved gases and other chemicals. Water has the ability to dissolve a vast number of natural and synthetic elements and compounds. It is often referred to as the ‘ universal solvent ’ . As water falls from the sky and runs through or across the land as surface run - off, it picks up a myriad of chemicals as dissolved substances. It may also collect further materials, including chemicals that are insoluble but are suspended in the water. This veritable soup supports a whole range of algae and invertebrates, which support the fi sh that are of greatest interest to the manager. Animals that live in water are very different to animals that live on land. Although this is obvious, the difference is rarely fully appreciated. To understand how to manage a fi shery we must understand the sorts of conditions the fi sh live in: their environmental conditions. Part I of this book looks at still - waters from the basic principles of how they work, con- sidering some of the conditions prevalent in still- waters and how these fl uctuate over time and space, and describes the various animals that live in them. 1 Introduction Ecologically, still - waters are described as standing ‘ open ’ water, a term that covers wetlands including fens, marshes and temporary fl ashes as well as inland water bodies such as lakes, ponds, meres and reservoirs. It is estimated that there are 3344 km 2 of still - waters in the UK, of which 95% are less than 1 hectare (1 hectare (ha) is equal to 10 000 m 2 ) in area, which means that there are at least 400 000 lakes, ponds and dams in the UK. It is also estimated that the number of still - waters has decreased by 35 – 75% over the past 100 years, although numbers are considered to have increased in recent years. The management of still - waters as ecologically important systems is therefore of high priority for the UK ’ s biodiversity and, as fi sheries are often the primary use of such waters, there will be a requirement for fi shery management skills that deal with the suitability of the environment to support fi sh. It is thought that as many as 90% of the nation’ s still - waters may be in private ownership and thus removed from the direct infl uence of conservation bodies, regulators and freshwater scientists, further emphasising the role of fi shery managers. In addition, UK managers often manage fi sheries on continental Europe, mainly for UK fi shermen. There has been a growing trend for the recreational fi sheries in England to be based in such still - waters, in particular those for coarse fi sh. This has created a need for the systematic management of many ponds, dams, gravel pits and lakes to maintain good populations of fi sh and good - quality fi sheries. At the same time, the management of such fi sheries is becom- ing increasingly complex. It is no longer suffi cient to keep a few fi sh in a pond, as increasing regulation and demands for high - quality fi shing experiences by the public force the manager 3 4 Fisheries Management to stricter policies. Underlying this is the fact that still- water pond management is a business in many instances and must satisfy customers to make a profi t by providing good - quality fi shing; the manager can only achieve this by providing a suitable environment and good - quality fi sh. Fisheries management, in common with most other activities that involve a combination of problem solving and improvement that result in physical solutions, requires that well - developed planning is a necessary part of the process. Fishery managers are no different from us all in as much as we all plan. We all plan to lesser or greater degrees: we plan what we are going to eat, for example, and where and when we are going to buy the food we have decided to eat. However, the way we approach fi sheries management planning often needs to be more prescriptive. Each fi shery will ideally have a written management plan that will have been developed for it; certainly where the fi shery management involves more than a solitary individual a plan should be developed and put in place as a priority. It is important to ensure that the aims and objectives are clear and understood, that the actions required to achieve them are well considered and planned, and that the tools to measure or monitor the management actions are in place at the onset of the plan and not developed as an afterthought.