Abstract

This paper examines the practical use of physical biotopes as the basic component of instream physical habitat. These are identified by dominant flow type as a particular combination of substrate and hydraulic parameters will have a characteristic surface flow type. Eleven rivers representing a range of geomorphological features and physical biotopes were selected, and depth, velocity, and substrate data were collected at metre intervals in subjectively-spaced transects. Flow type was recorded at each sample “cell” and transects classified on the basis of dominant flow type. Combined hydraulic indices were calculated in order to characterise more completely a particular biotope and to facilitate comparisons among different discharges and sites.

The subjective classification of flow types was tested statistically by discriminant analysis and units were shown to be hydraulically discrete in terms of Froude number and other combined hydraulic indices. Identification of physical biotopes by flow types has been incorporated into the Environment Agency’s (formerly National Rivers Authority) River Habitat Survey (RHS). The RHS is based on 500 m reaches selected randomly within a stratified selection from a national grid, to characterise the physical features of rivers in England and Wales, and to provide an objective method for assessing habitat quality.

Biotope mapping at different flows was undertaken to establish how the biotope sequence differs among sites and with increasing discharge. Threshold discharges at which biotopes change are related to flow duration data to predict annual patterns of biotope ‘patchiness’ and ‘diversity’. Flows may then be manipulated to maintain ‘natural’ or ‘desirable’ biotopes. Sustainable management of aquatic systems and their biota would require flow management of critical reaches or biotopes, at key life-stages of target organisms.

The text of this article is only available as a PDF.

References

Armitage, P.D.
1995
. “
Faunal community change in response to flow manipulation
”. In
The Ecological Basis for River Management
, Edited by: Harper, D.M. and Ferguson, A.J.D.
59
78
.
Chichester
:
Wiley
.
In
Barmuta, L.A.
1989
.
Habitat patchiness and macrobenthic community structure in an upland stream in temperate Victoria, Australia
.
Freshwater Biol.
,
21
:
223
236
.
Boon, P.J.
1996
. “
Assessing nature conservation value. SERCON (System for Evaluating Rivers for Conservation)
”. In
Freshwater Quality: Defining the Indefinable?
, Edited by: Boon, P.J. and Howell, D.L.
299
326
.
London
:
Her Majesty's Stationery Office
.
In
Brookes, A.
1995
. “
The importance of high flows for riverine environments
”. In
The Ecological Basis for River Management
, Edited by: Harper, D.M. and Ferguson, A.J.D.
33
50
.
Chichester
:
Wiley
.
In
Brussock, P.P. and Brown, A.V.
1991
.
Riffle-pool geomorphology disrupts longitudinal patterns of stream benthos
.
Hydrobiologia
,
220
:
109
117
.
Church, M.
1992
. “
Channel morphology and typology
”. In
The Rivers Handbook Volume 1
, Edited by: Calow, P. and Petts, G.E.
126
143
.
Oxford
:
Blackwell Scientific Publications
.
In
Davis, J.A. and Barmuta, L.A.
1989
.
An ecologically useful classification of mean and near-bed flows in streams and rivers
.
Freshwater Biol.
,
21
:
271
282
.
Frissell, C.A., Liss, W.J., Warren, C.E. and Hurley, M.D.
1986
.
A hierarchical framework for stream habitat classification: viewing streams in a watershed context
.
Environ. Manage.
,
10
:
199
214
.
Grundy, J.
1996
. “
Flow Types and Stream Ecology: Putting Flow Types into Practice
”. In
Project completion report to Environment Agency
,
Department of Geography, University of Newcastle upon Tyne
.
Gustard, A., Cole, G., Marshall, D. and Bayliss, A., eds.
1987
.
A Study of Compensation Flows in the UK
,
Report No. 99
115
115
.
Wallingford, , UK
:
Institute of Hydrology
.
Harper, D.M., Smith, C.D. and Barham, P.J.
1992
. “
Habitats as the building blocks for river conservation assessment
”. In
River Conservation and Management
, Edited by: Boon, P.J., Calow, P. and Petts, G.E.
311
319
.
Chichester
:
Wiley
.
In
Harper, D.M., Smith, C.D., Barham, P.J. and Howell, R.
1995
. “
The ecological basis for the management of the natural river environment
”. In
The Ecological Basis for River Management
, Edited by: Harper, D.M. and Ferguson, A.J.D.
219
238
.
Chichester
:
Wiley
.
In
Hildrew, A.G. and Giller, P.S.
1994
. “
Patchiness, species interactions and disturbance in the stream benthos
”. In
Aquatic Ecology: Scale, Pattern and Process. Symposium of the British Ecological Societ
, Edited by: Giller, P.S., Hildrew, A.G. and Raffaelli, D.G.
21
62
.
Oxford
:
Blackwell
.
In
Huryn, A.D. and Wallace, J.B.
1987
.
Local geomorphology as a determinant of macrofaunal production in a mountain stream
.
Ecology
,
68
(
6
):
1932
1942
.
Jowett, I.G.
1993
.
A method for objectively identifying pool, run and riffle habitats from physical measurements
.
N. Z. J. Mar. Freshwater Res.
,
27
:
41
248
.
Jowett, I.G., Richardson, J., Biggs, B.J.F., Hickey, C.W. and Quinn, J.M.
1991
.
Microhabitat preferences of benthic invertebrates and the development of generalised Deleatidium spp. habitat suitability curves, applied to four New Zealand rivers
.
N. Z. J. Mar. Freshwater Res.
,
25
:
187
199
.
Lancaster, J. and Hildrew, A.G.
1993
.
Flow refugia and the microdistribution of lotic macroinvertebrates
.
J. North. Am. Benthol. Soc.
,
12
:
385
393
.
Lancaster, J. and Hildrew, A.G.
1993
.
Characterising in-stream flow refugia
.
Can. J. Fish. Aquat. Sci.
,
50
:
1663
1675
.
Milner, N., Wyatt, R.J. and Scott, M.D.
1993
.
Variability in the distribution and abundance of stream salmonids, and the associated use of habitat models
.
J. Fish Biol.
,
43
:
103
109
.
(Supplement A)
Milner, A.M.
1994
. “
System recovery
”. In
The Rivers Handbook Volume 2
, Edited by: Petts, G.E. and Calow, P.
76
97
.
Oxford
:
Blackwell Scientific
.
In
Naiman, R.J., Decamps, H., Pastor, J. and Johnston, C.
1988
.
The potential importance of boundaries to fluvial ecosystems
.
J. North. Am. Benthol. Soc.
,
7
:
289
306
.
National Rivers Authority
.
1994
.
River Habitat Survey Phase 2: Field Testing Guidance Manual
Unpublished report P-79331.TL
National Rivers Authority
.
1996
.
River Habitats in England and Wales: a National Overview
,
River Habitat Survey Report No. 1
Bristol, , UK
O'Keeffe, J.
1997
. “
Assessing the nature conservation value: a broader international view
”. In
Freshwater Quality: Defining the Indefinable?
, Edited by: Boon, P.J. and Howell, D.L.
369
386
.
London
:
Her Majesty's Stationery Office
.
In
Ormerod, S.J. and Edwards, R.W.
1987
.
The ordination and classification of macroinvertebrate assemblages in the catchment of the River Wye in relation to environmental factors
.
Freshwater Biol.
,
17
:
533
546
.
Orth, D.J. and Maughan, O.E.
1983
.
Microhabitat preferences of benthic fauna in a woodland stream
.
Hydrobiologia
,
106
:
157
168
.
Padmore, C.L.
1997
. “
Biotopes and their hydraulics: a method for defining the physical component of freshwater quality
”. In
Freshwater Quality: Defining the Indefinable?
, Edited by: Boon, P.J. and Howell, D.L.
251
257
.
London
:
Her Majesty's Stationery Office
.
In
Padmore, C.L.
1997
.
Physical biotopes in representative river channels: identification, characterisation and application
,
UK
:
The University of Newcastle upon Tyne
.
Ph.D. thesis
Padmore, C.L., Newson, M.D. and Charlton, M.E.
Gravel Bed Rivers in the Environment
.
Proceedings of the 4th International Gravel Bed Rivers Conference
.
Instream habitat in gravel bed rivers: identification and characterisation of biotopes
,
Oregon State University Press
.
In press
Petts, G.E., Maddock, I., Bickerton, M. and Ferguson, A.J.D.
1995
. “
Linking hydrology and ecology: the scientific basis for river management
”. In
The Ecological Basis for River Management
, Edited by: Harper, D.M. and Ferguson, A.J.D.
1
16
.
Chichester
:
Wiley
.
In
Platts, W.S., Megahan, W.F. and Minshall, G.W.
1983
.
Methods for evaluating stream, riparian and biotic conditions
,
General Technical Report INT-138
United States Department of Agriculture, Forest Service
.
Raven, P.J., Fox, P., Everard, M., Holmes, N.T.H. and Dawson, F.H.
1997
. “
River Habitat Survey: a new system for classifying rivers according to their habitat quality
”. In
Freshwater Quality: Defining the Indefinable?
, Edited by: Boon, P.J. and Howell, D.L.
215
234
.
London
:
Her Majesty's Stationery Office
.
In
Rutt, G.P., Weatherley, N.S. and Ormerod, S.J.
1989
.
Microhabitat availability in Welsh moorland and forest streams as a determinant of macroinvertebrate distribution
.
Freshwater Biol.
,
22
:
247
261
.
SAS
.
1985
.
SAS User's Guide
,
Cary, North Carolina
:
SAS Institute
.
Sheail, J.
1987
. “
Historic development of setting compensation flows
”. In
A Study of Compensation Flows in the UK. Report No. 99, Appendix 1
, Edited by: Gustard, A., Cole, G., Marshall, D. and Bayliss, A.
1
28
.
Wallingford, , UK
:
Institute of Hydrology
.
In
Statzner, B.
1981
.
A method to estimate the population size of benthic macroinvertebrates in streams
.
Oecologia
,
51
:
157
161
.
Statzner, B., Gore, J.A. and Resh, V.H.
1988
.
Hydraulic stream ecology: observed patterns and potential applications
.
J. North. Am. Benthol. Soc.
,
7
(
4
):
307
360
.
Sullivan, K.
1986
.
Hydraulics and fish habitat in relation to channel morphology
, Vol.
16
,
65
65
.
Baltimore
:
The John Hopkins University
.
Ph.D. Thesis3
Swales, S. and Harris, J.H.
1995
. “
The expert panel assessment method (EPAM): a new tool for determining environmental flows in regulated rivers
”. In
The Ecological Basis for River Management
, Edited by: Harper, D.M. and Ferguson, A.J.D.
1
16
.
Chichester
:
Wiley
.
In
Townsend, C.R.
1989
.
The patch dynamics concept of stream community ecology
.
J. North. Am. Benthol. Soc.
,
8
:
36
50
.
Townsend, C.R. and Hildrew, A.G.
1994
.
Species traits in relation to a habitat templet for river systems
.
Freshwater Biol.
,
31
:
265
275
.
Wadeson, R.A.
1994
.
A geomorphological approach to the identification and classification of instream flow environments
.
S. Af. J. Aquatic Sci.
,
20
(
1
):
1
24
.
Wadeson, R.A.
1995
.
The development of the hydraulic biotope concept within a catchment based hierarchical geomorphological model
,
Grahamstown, , South Africa
:
Rhodes University
.
Ph.D. thesis
Wadeson, R.A. and Rowntree, K.M.
Classification of rivers, and environmental health indicators
.
Proceedings of a joint SA-Australian workshop
.
February 7–14 1994
.
A hierarchical geomorphological model for the classification of South African river systems
, Edited by: Uys, M.C.
Cape Town, , South Africa
Water Research Commission Report no. TT63/94
White, P.S. and Pickett, S.T.A.
1985
. “
Natural disturbance and patch dynamics: an introduction
”. In
The Ecology of Natural Disturbance and Patch Dynamics
, Edited by: White, P.S. and Pickett, S.T.A.
3
13
.
New York
:
Academic Press
.
In