Freshwater Ecology and Conservation Techniques in Ecology and Conservation Series Series Editor: William J. Sutherland Bird Ecology and Conservation: A Handbook of Techniques William J. Sutherland, Ian Newton, and Rhys E. Green Conservation Education and Outreach Techniques Susan K. Jacobson, Mallory D. McDuff, and Martha C. Monroe Forest Ecology and Conservation: A Handbook of Techniques Adrian C. Newton Habitat Management for Conservation: A Handbook of Techniques Malcolm Ausden Conservation and Sustainable Use: A Handbook of Techniques E.J. Milner-Gulland and J. Marcus Rowcliffe Invasive Species Management: A Handbook of Principles and Techniques Mick N. Clout and Peter A. Williams Amphibian Ecology and Conservation: A Handbook of Techniques C. Kenneth Dodd, Jr. Insect Conservation: A Handbook of Approaches and Methods Michael J. Samways, Melodie A. McGeoch, and Tim R. New Remote Sensing for Ecology and Conservation: A Handbook of Techniques Ned Horning, Julie A. Robinson, Eleanor J. Sterling, Woody Turner, and Sacha Spector Marine Mammal Ecology and Conservation: A Handbook of Techniques Ian L. Boyd, W. Don Bowen, and Sara J. Iverson Carnivore Ecology and Conservation: A Handbook of Techniques Luigi Boitani and Roger A. Powell Primate Ecology and Conservation: A Handbook of Techniques Eleanor J. Sterling, Nora Bynum, and Mary E. Blair Conservation Education and Outreach Techniques, Second Edition Susan K. Jacobson, Mallory D. McDuff, and Martha C. Monroe Reptile Ecology and Conservation: A Handbook of Techniques C. Kenneth Dodd, Jr. Social Science Theory for Environmental Sustainability: A Practical Guide Marc J. Stern Freshwater Ecology and Conservation: Approaches and Techniques Jocelyne M. R. Hughes Freshwater Ecology and Conservation Approaches and Techniques Edited by Jocelyne M.R. Hughes 1 1 Great Clarendon Street, Oxford, OX2 6DP, United Kingdom Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries © Oxford University Press 2019 The moral rights of the authors have been asserted First Edition published in 2019 Impression: 1 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, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, by licence or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this work in any other form and you must impose this same condition on any acquirer Published in the United States of America by Oxford University Press 198 Madison Avenue, New York, NY 10016, United States of America British Library Cataloguing in Publication Data Data available Library of Congress Control Number: 2018948522 ISBN 978–0–19–876638–4 (hbk.) ISBN 978–0–19–876642–1 (pbk.) DOI: 10.1093/oso/9780198766384.001.0001 Printed in Great Britain by Bell & Bain Ltd., Glasgow Links to third party websites are provided by Oxford in good faith and for information only. Oxford disclaims any responsibility for the materials contained in any third party website referenced in this work. Preface Water underpins all life on Earth, and in particular, hydrology and water chemistry play a signature role in maintaining the structure and function of freshwater ecosys- tems. Despite the manifest importance of freshwater, and the human dependence on healthy freshwater ecosystems, wetlands have continued to be degraded, polluted, and drained, and freshwater species have declined at an alarming rate—for example, the well-documented decline of global amphibians. This book aims to provide a com- prehensive and concise synthesis of the vast literature on the techniques used in freshwater ecology and conservation that is currently dispersed globally in manuals, toolkits, journals, handbooks, ‘grey’ literature, and websites. It should be regarded as a ‘book of books’, and it is on this basis that the late Brian Moss encouraged me to carry out the project. The book is intended to provide a thorough understanding of different approaches and techniques needed for successful research, management, and conser- vation of freshwater ecosystems. Freshwater conservationists and practitioners often need to understand hydrochemical storages and fluxes in wetlands, the physical pro- cesses influencing freshwaters at the catchment and landscape scale, and the hydro- chemical processes that maintain species assemblages and their dynamics. Conservation builds on a sound ecological framework, in which each species must be examined at the individual, community, and catchment level of interaction, and in which human interactions with freshwaters are a critical part. The survey approaches and techniques used, and the subsequent analytical methods, directly affect the interpretation of results, and it is essential to understand their limitations or biases in order to make informed decisions on conservation and management. This book cannot list all tech- niques used to survey or sample freshwaters—that is an impossible task; rather, it presents some of the practical approaches that are used in freshwater ecological research and surveys, and, using examples from international studies, synthesises why certain methods are used in preference to others for particular types of freshwater habitat or particular types of organism, or for measuring, documenting, and evaluating the dynamics and management of the ecosystem. Central to all freshwater surveys is the identification of organisms to the species level. This book does not attempt to cover identification and taxonomy although passing reference is made to new methods in species identification in some chapters. The book is divided into three parts. The first part is an overview, presenting an outline of the diversity of freshwater ecosystems; the importance of hydrology and water chemistry in driving ecosystem processes; the different approaches required to answer questions in freshwater ecology and provide effective solutions to conservation problems, including the essential nexus between scientists, social scientists, and stake- holder participation; and an overview of sampling strategies and protocols used in freshwater investigations. The second part describes the techniques needed to quantify the individual physical and biological components of the ecosystem, including, for vi | Preface example, water quantity, water chemistry, aquatic plants, aquatic animals, and algae. This section summarises the huge array of approaches and techniques used for survey- ing and measuring the multitude of organisms to be found in freshwaters and their physical environment, and that are needed to answer questions on—for example— species richness and abundance, species hydrochemical preferences and tolerances, or the impacts of human populations on freshwater ecosystems. The final part deals with the bigger picture in conservation and management and the approaches needed to answer complex questions involving different stakeholders. It brings together the different approaches and techniques needed to understand interactions between the physical and biological components of freshwater ecosystems, changes over time and ecosystem dynamics, human dependency on and interactions with freshwaters, and the conservation, management, and evaluation of these ecosystems. Individual chap- ters synthesise approaches and methods drawn from science, economics, landscape management, and engineering; for example, evaluating the restoration of eutrophic waters, monitoring the spread and control of non-native invasive species, and quanti- fying ecosystem services. I would like to thank the people who assisted in the production of this book— in reviewing, editing, discussing the contents, making suggestions, and providing moral support: Flora Botsford, David Bradley, Ana Castro Castellon, C. Ken Dodd Jr., the late Mike Edmunds, François Edwards, Max Finlayson, Dustin Garrick, Thomas Hesselberg, Francine Hughes, Lizzy Jeffers, Tim Johns, Curt Lamberth, the late Brian Moss, Liz Sanders, Carl Sayer, Rebecca Tharme, Jennie Whinam; seven anonymous referees; and the fantastic team of lead authors and co-authors who c ontributed to this book and helped with the reviewing. I would like to thank my previous department at Oxford—the Department for Continuing Education—that supported a six-month sabbatical that enabled me to focus on developing this book. I am so grateful to the inspirational, international students I teach on the MSc in Water Science, Policy and Management, the Postgraduate Certificate in Ecological Survey Techniques, and the Postgraduate Diploma in International Wildlife Conservation Practice at the University of Oxford, who are justification alone for this project and have taught me the vital importance of training early career researchers and practitioners in field skills, practical surveys, and analytical methods. I would like to thank Lydia Shinoj and Paul Nash at SPi Global for their infinite patience. At Oxford University Press I would like to thank Bethany Kershaw, Lucy Nash, and Ian Sherman; and the overall editor of the Techniques in Ecology and Conservation Series, Bill Sutherland, for giving me the chance of steering this project. Finally, I could not have completed this volume without the infinite support of my beloved family: my life-long partner Charles, and our children George, Madeleine, and Fifi; and my parents, Arlette and Gren, and parent-in-law, Alison, who all three passed away during the production of the book and to whom I dedicate it. Jocelyne Hughes Department of Geography and the Environment, University of Oxford Contents List of Contributors xvii Part I Overall Considerations 1. Diversity of Freshwater Ecosystems and Global Distributions 3 G. Randy Milton and C. Max Finlayson 1.1 Introduction 3 1.2 Distribution and extent 4 1.3 Freshwater hydrology 5 1.4 Freshwater ecosystem diversity 7 1.4.1 Rivers 7 1.4.2 Lakes and reservoirs 8 1.4.3 Marshes and swamps 9 1.4.4 Peatlands—mires 10 1.4.5 Freshwater karst systems 12 1.5 Summary statement 14 References 15 2. Approaches to Freshwater Ecology and Conservation 20 Rebecca E. Tharme, David Tickner, Jocelyne M.R. Hughes, John Conallin, and Lauren Zielinski 2.1 Introduction 20 2.1.1 The situation—freshwater ecosystems, conservation status, and trends 20 2.1.2 The human factor in freshwater conservation and management 21 2.2 Framing freshwater conservation challenges 22 2.2.1 Scoping, objective setting, and guiding principles 22 2.2.2 Working with stakeholders from the inception 24 2.2.3 Sources of data, information, and knowledge 26 2.2.4 The importance of scale 27 2.3 Finding an approach appropriate for the context 28 2.3.1 Selecting from among the different types of approach 28 2.3.2 Illustrations of the diversity of approaches 30 2.3.3 Monitoring and evaluation, including a role for citizen science 32 2.4 Emerging approaches, sectors, and research arenas in freshwater ecology and conservation 35 2.4.1 Emerging technologies to collect ecological data at different scales 36 viii | Contents 2.4.2 Private sector water stewardship as a growing area for ecosystem conservation 37 2.5 Concluding remarks 38 References 40 3. Sampling Strategies and Protocols for Freshwater Ecology and Conservation 48 Leon A. Barmuta 3.1 Introduction 48 3.1.1 Objectives, research questions, developing and testing hypotheses 48 3.2 Sampling for ecology and sampling for conservation 50 3.2.1 Classes of sampling types 52 3.2.2 Logistic constraints 54 3.3 Habitat-centric strategies 55 3.4 Organism-centric strategies 56 3.5 Temporal considerations 58 3.6 Conclusion 58 References 58 Part II Measuring the Component Parts 4. Water Quantity and Hydrology 67 Matthew McCartney 4.1 Introduction 67 4.2 Hydrological monitoring 68 4.2.1 Data collection 68 4.2.2 Monitoring networks 78 4.3 Data analyses 80 4.3.1 Residence time 80 4.3.2 Areal rainfall 80 4.3.3 Hydrological modelling 81 4.3.4 Environmental flows 81 4.4 Case study: hydrological assessment for wetland conservation at Wicken Fen 83 4.5 Conclusion 85 References 85 5. Chemical Determinands of Freshwater Ecosystem Functioning 89 Nic Pacini, Libor Pechar, and David M. Harper 5.1 The influence of geology, morphology, climate, and land use 89 Contents | ix 5.2 pH and dissolved oxygen 90 5.2.1 Acidity 90 5.2.2 pH measurement 91 5.2.3 Oxygen measurement 93 5.2.4 Significance of pH ranges 93 5.2.5 Acidity/alkalinity buffering 94 5.3 Inorganic carbon, major ions, and conductivity 95 5.3.1 Inorganic carbon 95 5.3.2 Carbon measurement 95 5.3.3 Major ions and conductivity 96 5.4 Organic carbon and nutrients 97 5.4.1 Organic carbon 97 5.4.2 Nutrients 98 5.5 Heavy metals and xenobiotic compounds 100 5.6 Chemical analysis 101 References 103 6. Physical Variables in Freshwater Ecosystems 106 Curt Lamberth and Jocelyne M.R. Hughes 6.1 Introduction 106 6.2 Approaches to collecting physical variables 107 6.2.1 Habitat and sampling considerations 107 6.2.2 Battery considerations 107 6.3 Catchment setting 109 6.3.1 Bathymetry, topography, area, and length 109 6.3.2 Water depths and levels 110 6.3.3 Geology 112 6.4 In and near to the water 113 6.4.1 Temperature and humidity 113 6.4.2 Colour, clarity, turbidity, and suspended sediment 116 6.4.3 Solar radiation and PAR 117 6.4.4 Evaporation and evapotranspiration 118 6.5 Substrate 120 6.5.1 Sampling 120 6.5.2 Type of substrate and soil characterisation 121 6.5.3 Sedimentation, accretion, and erosion 123 6.5.4 Texture, particle size, porosity, penetrability, and soil moisture 123 6.6 Examples 124 References 126 7. Microorganisms 1: Phytoplankton, attached algae, and biofilms 133 David C. Sigee 7.1 Introduction 133