Planet WGSW-24010 User manual

Mean Trophic Rank: A User’s Manual
R&D Technical Report E38
NTH Holmes3, JR Newman2, S Chadd4, KJ Rouen4, L Saint4and FH Dawson1
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Research contractors:
NERC Institute of Freshwater Ecology 1
with IACR Centre for Aquatic Plant Management 2
and Alconbury Environmental Consultants 3
Environment Agency 4
Rio House
Waterside Drive
Aztec West
Almondsbury
BRISTOL
BS32 4UD

R&D Technical Report E38
Publishing Organisation
Environment Agency
Rio House
Waterside Drive
Aztec West
Almondsbury
Bristol BS32 4UD
Tel: [phone] Fax: [phone]
ISBN: 1 85705 092 4
© Environment Agency 1999
All rights reserved. No parts of this document may be produced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or
otherwise without the prior permission of the Environment Agency.
The views expressed in this document are not necessarily those of the Environment Agency. Its
Officers, servants or agents accept no liability whatsoever for any loss or damage arising from the
interpretation or use of the information, or reliance on the views contained herein.
Dissemination status
Internal: Released to Regions
External: Public Domain
Statement of Use
This report sets out procedural guidance on how to carry out Mean Trophic Rank (MTR)
macrophyte surveys to assess the trophic status of rivers, and on the use of the method for the
purposes of the EC Urban Waste Water Treatment Directive. The methodology can also be used
for other applications. The guidance supersedes and replaces earlier, internal guidance issued to
Environment Agency staff. It is intended as ‘best practice’ standard methodology for all MTR
surveys and is applicable throughout the UK.
Research Contractor
This document was produced under R&D Project E1-i694 by:
NERC Institute of Freshwater Ecology IACR Centre for Aquatic Plant Management
The Rivers Laboratory, East Stoke Broadmoor Lane, Sonning, Reading
Wareham, Dorset, BH20 6BB Reading, Berkshire, RG4 0TH
Tel: [phone] Fax: -462180 Tel: [phone]
Institute of Freshwater Ecology - disclaimer IFE report reference RL/T4073Q7/7. In
accordance with the normal practice of the NERC Institute of Freshwater Ecology, this report was
prepared for use by the party to whom it is addressed (Environment Agency) and no responsibility
is accepted for the interpretation by any third party for the whole or any part of its contents.
Environment Agency's Project Manager
The Environment Agency's Project Manager for R&D Project E1-i694:
Karen J Rouen, North West Region

R&D Technical Report E38 i
ACKNOWLEDGEMENTS
This document is intended as a description of a standard methodology for the assessment
of the trophic status of rivers using macrophytes applicable throughout the United Kingdom.
Its production would not have been possible without the cooperation and assistance of Dr
Nigel Holmes, English Nature, Scottish Natural Heritage, The Countryside Commission
for Wales, the Industrial Research and Technology Unit (Northern Ireland) and the
Scottish and Northern Ireland Forum for Environmental Research (SNIFFER).

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R&D Technical Report E38 iii
CONTENTS
List of Figures v
List of Tables v
Glossar y vi
Executive Summary ix
Key Words ix
1Foreword 1
1.1 About this manual 1
1.2 Summary of the method 3
2Introduction to MTR 5
2.1 What is MTR? 5
2.2 Uses of MTR 8
2.3 Principal application: Urban Waste Water Treatment Directive 9
2.4 Other applications 11
3Survey Planning 15
3.1 Alternative methods to consider 15
3.2 Sampling strategy 20
3.3 Logistics of sampling 22
3.4 Ancillary data collection 29
3.5 Limitations of the method 31
4How to Carry Out an MTR Survey 33
4.1 Overview of the methodology 33
4.2 Preparation and pre-survey checks 33
4.3 Site and survey details 33
4.5 Carrying out the macrophyte survey 38
4.6 Assessing and recording physical variables 49
4.7 Laboratory Analysis 58
5MTR Data Analysis 61
5.1 Calculating Mean Trophic Ranks 61
5.2 Assigning a measure of confidence to the MTR 62
5.3 Assessment of confidence in the data 63
5.4 Data storage 64
6Interpretation of MTR Results 65
6.1 Interpretation for the purposes of the UWWTD 65

R&D Technical Report E38 iv
6.2 Interpretation for other purposes 72
6.3 Interpretation of species diversity 74
6.4 Interpretation of overall percentage cover values 76
7Quality Assurance 77
7.1 Introduction 77
7.2 Training 80
7.3 Audit surveys 82
7.4 Inter-calibration exercise 88
7.5 Database verification 89
7.6 Survey length selection 90
8MTR Best Practice Checklist 91
8.1 Uses of MTR 91
8.2 Survey planning 91
8.3 Survey methodology 92
8.4 Data analysis 92
8.5 Interpretation of results 93
8.6 Quality assurance 93
9References 95
Appendices 99
Appendix 1 Rare plants 100
Appendix 2 Foreign invasive plant species 101
Appendix 3 Identification guides and preservation manuals 102
Appendix 4 Equipment suppliers 104
Appendix 5 Standard record sheets 105
Appendix 6 Example sketch maps 121
Appendix 7 Summary of methodology, definitions and equipment checklist 125
Index 131

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R&D Technical Report E38 vi
LIST OF FIGURES
1Diagrammatic representation of survey method 38
2Illustration of shading 53
3Macrophyte survey flow chart 60
4Interpretation of MTR results, Stage I ‘decision tree’:
Is the site impacted by eutrophication? 70
5Interpretation of MTR results, Stage II ‘decision tree’:
Is there a significant downstream impact from the qualifying discharge? 71
LIST OF TABLES
1MTR scores summarised according to river community type 68
2Reasons for mismatch between audit and primary surveys, with suggested actions 87
A1 List of Mean Trophic Rank scoring taxa, with recent synonyms 111
A2 Cover (m2) for 100m Survey Lengths 119
LIST OF TEXT BOXES
1Factors to consider when deciding whether to use MTR or DQI/TDI 18
2Factors to consider when selecting MTR sites and survey lengths 24
3Conditions when surveys should not be undertaken 26
4Non-standard survey lengths 36
5Exceptions to surveying the full channel width 37
6Methods of estimating overall percentage cover 43
7Estimating percentage cover of individual species: width method 45
8Estimating percentage cover of individual species: square metre method 46
9Audit procedure 85

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GLOSSARY
Audit survey Repeat survey undertaken for quality assurance purposes.
CCW Countryside Council for Wales.
Channel area The part of the river channel where macrophytes are seen submerged or
partly submerged at low flow levels. At the sides of the channel this
includes all macrophytes attached or rooted on parts of the substrata
which are likely to be submerged for more than 85% of the year.
Comparability A measure of confidence in the physical
comparability of a pair of sites
based upon the similarity of width, depth, substrata, habitat, shading,
water clarity and bed stability.
CVS
Cover Value Score
. The score allocated to a species resulting from the
multiplication of the Species Trophic Rank and the Species Cover Value.
DoE The Department of the Environment.
d/s Downstream.
EN English Nature.
DQI The Diatom Quality Index. A transformation of the
Trophic Diatom Index
for use when comparing TDI and MTR results.
Highlighted species Refers to a plant species within MTR which is believed to be a particularly
reliable indicator of trophic status.
IFE The Institute of Freshwater Ecology.
IRTU Industrial Research & Technology Unit, Northern Ireland.
LEAP Local Environment Agency Plan.
Macrophyte Larger alga or higher aquatic plant (including bryophytes), observable to
the naked eye and nearly always identifiable when observed.
MTR Mean Trophic Rank. A numerical score assigned to a survey length based
on its macrophyte presence and abundance characteristics.
Nitrate Dissolved or soluble or non-particulate nitrate.
Non-QD Non-qualifying discharge under the UWWTD, with a population
equivalent of less than 10,000.