AUSRIVAS- Australia’s in-stream
biological health 2003-2010
DECEMBER 2011
PRODUCED BY Evan Harrison, Susan Nichols, Bernd Gruber, Fiona Dyer, Alica Tschierschke
and Richard Norris, Institute for Applied Ecology, University of Canberra
FOR the Department of Sustainability, Environment, Water, Population and Communities
ON BEHALF OF the State of the Environment 2011 Committee
Citation:
Harrison E., Nichols S., Gruber B., Dyer F, Tschierschke A and Norris R. AUSRIVAS- Australia’s in-stream
biological health 2003-2010. Report prepared for the Australian Government Department of Sustainability,
Environment, Water, Population and Communities on behalf of the State of the Environment 2011 Committee.
Canberra: DSEWPaC, 2011.
Produced by:
Institute for Applied Ecology
University of Canberra, ACT 2601
Telephone:
(02) 6201 5839
Facsimile:
(02) 6201 5651
Website: www.appliedecology.edu.au
ABN: 81 633 873 422
Inquiries regarding information in this document should be addressed to:
Dr Evan Harrison
Phone: 02 6201 2080
Email: Evan.Harrison@canberra.edu.au
Fax: 02 6201 5651
© Commonwealth of Australia 2011
This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be
reproduced by any process without prior written permission from the Commonwealth. Requests and enquiries
concerning reproduction and rights should be addressed to Department of Sustainability, Environment, Water,
Populations and Communities, Public Affairs, GPO Box 787 Canberra ACT 2601 or email
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Disclaimer
The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those
of the Australian Government or the Minister for Sustainability, Environment, Water, Population and
Communities or the 2011 State of the Environment Committee or the state governments.
While reasonable efforts have been made to ensure that the contents of this publication are factually correct, the
Commonwealth, State or the 2011 State of the Environment Committee do not accept responsibility for the
accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned
directly or indirectly through the use of, or reliance on, the contents of this publication.
This product is based on data provided by: the ACT Department of Territory and Municipal Services; ACTEW
AGL; ALS Water Resources Group; the Department of Environment and Conservation, Western Australia; the
Department of Environment and Resource Management, Queensland; the Department of Natural Resources
Environment & the Arts, Northern Territory; the Department of Primary Industries, Parks, Water and
Environment, Tasmania; Environment Protection Authority, South Australia; EPA Victoria; Kosciuszko
Thredbo Ltd; New South Wales Department of Environment and Climate Change, and New South Wales
National Parks and Wildlife.
These groups s give no warranty in relation to the data (including accuracy, reliability, completeness, currency
or suitability) and accepts no liability (including without limitation, liability in negligence) for any loss, damage
or costs (including consequential damage) relating to any use of the data.
Cover image
Cadjeput Waterhole on the Fitzroy River, WA
Photo by Nick Rains
Australia ■ State of the Environment 2011 Supplementary information
i
Preface
This report was commissioned by the Department of Sustainability, Environment, Water,
Population and Communities to help inform the Australia State of the Environment (SoE)
2011 report. As part of ensuring its scientific credibility, this report has been independently
peer reviewed.
The Minister for Environment is required, under the Environment Protection and Biodiversity
Conservation Act 1999, to table a report in Parliament every five years on the State of the
Environment.
The Australia State of the Environment (SoE) 2011 report is a substantive, hardcopy report
compiled by an independent committee appointed by the Minister for Environment. The
report is an assessment of the current condition of the Australian environment, the pressures
on it and the drivers of those pressures. It details management initiatives in place to address
environmental concerns and the effectiveness of those initiatives.
The main purpose of SoE 2011 is to provide relevant and useful information on
environmental issues to the public and decision-makers, in order to raise awareness and
support more informed environmental management decisions that lead to more sustainable
use and effective conservation of environmental assets.
The 2011 SoE report, commissioned technical reports and other supplementary products are
available online at www.environment.gov.au/soe.
Australia ■ State of the Environment 2011 Supplementary information
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Contents
ACKNOWLEDGEMENTS ................................................................................................ 1
KEY FINDINGS .............................................................................................................. 2
1 INTRODUCTION ......................................................................................................... 3
1.2 Using AUSRIVAS to measure in-stream biological health ...................................................... 3
1.2 2003-2010 State of the Environment (SoE) reporting of in-stream biological health ........... 4
2 DATA ANALYSIS......................................................................................................... 6
2.1 AUSRIVAS data ................................................................................................................... 6
2.2 Mapping AUSRIVAS data .................................................................................................... 6
2.3 Macroinvertebrate taxonomic richness ............................................................................. 6
2.4 Data analysis limitations ..................................................................................................... 7
3 RESULTS AND INTERPRETATION ................................................................................ 7
3.1 National .................................................................................................................................. 7
3.1.2 Comparison with 2001 and 2006 SoE results ................................................................ 10
3.2 State and Territory ............................................................................................................... 11
3.2.1 Queensland.................................................................................................................... 11
3.2.2 New South Wales .......................................................................................................... 16
3.2.3 Australian Capital Territory ........................................................................................... 20
3.2.4 Victoria .......................................................................................................................... 25
3.2.5 Tasmania........................................................................................................................ 29
3.2.6 Northern Territory ......................................................................................................... 34
3.2.7 South Australia .............................................................................................................. 39
3.2.7 Western Australia .......................................................................................................... 44
Australia ■ State of the Environment 2011 Supplementary information
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List of tables
Table 1. Definitions of terms used in AUSRIVAS assessment. .......................................................... 3
Table 2. O:E score bands, description and interpretations used for AUSRIVAS reporting .............. 5
Table 3. Number of AUSRIVAS macroinvertebrate bioassessment reference site O:E scores
classed within each band of biological condition (all states and territories 2003-2010). ...................... 8
Table 4. Number of AUSRIVAS macroinvertebrate bioassessment test site O:E scores classed
within each band of biological condition (all states and territories 2003-2010).................................... 8
Table 5. Comparison of test sites assessed using AUSRIVAS macroinvertebrate bioassessment
within each AUSRIVAS OE score band for SoE 2011, SoE 2006 and SoE 2001. .................................... 10
Australia ■ State of the Environment 2011 Supplementary information
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List of figures
Figure 1. Proportion of reference sites across Australia within each AUSRIVAS O:E score band of
biological condition 2003-2010.. ............................................................................................................ 9
Figure 2. Proportion of test sites across Australia within each AUSRIVAS O:E score band of
biological condition 2003-2010. ............................................................................................................. 9
Figure 3. Summary of AUSRIVAS O:E scores for all river sites surveyed in Queensland (numbers
refer to Australian Water Resources Council [AWRC] basins). ............................................................. 12
Figure 4. Number of visits per reference site within Queensland 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 13
Figure 5. Number of visits per test site within Queensland 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 13
Figure 6. Proportion of reference sites in Queensland within each AUSRIVAS O:E score band
2003-2010. ............................................................................................................................................ 14
Figure 7. Proportion of test sites in Queensland within each AUSRIVAS O:E score band 2003-2010
.............................................................................................................................................................. 14
Figure 8. Percentage of sites sampled within each habitat and season in Queensland for each
macroinvertebrate taxonomic richness category. ................................................................................ 15
Figure 9. Summary of AUSRIVAS O:E scores for all river sites surveyed in New South Wales during
2003-2010 (numbers refer to AWRC basins). ....................................................................................... 16
Figure 10. Number of visits per reference site within New South Wales 2003-2010 (visits per site
are categorized as 1-5, 6-10,11-15 etc). ............................................................................................... 17
Figure 11. Number of visits per test site within New South Wales 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 17
Figure 12. Proportion of reference sites in New South Wales within each AUSRIVAS O:E score
band 2003-2010. ................................................................................................................................... 18
Figure 13. Proportion of test sites in New South Wales within each AUSRIVAS O:E score band
2003-2010. ............................................................................................................................................ 18
Figure 14. Percentage of sites sampled within each habitat and season in New South Wales for
each macroinvertebrate taxonomic richness category. ....................................................................... 19
Figure 15. Summary of site assessments based on AUSRIVAS O:E scores for all river sites sampled
in the Australian Capital Territory and upper Murrumbidgee Catchment (numbers refer to AWRC
basins) during 2003-2010. .................................................................................................................... 21
Figure 16. Number of visits per reference site within the Australian Capital Territory and upper
Murrumbidgee Catchment 2003-2010 (visits per site are categorized as 1-5, 6-10,11-15 etc). .......... 22
Australia ■ State of the Environment 2011 Supplementary information
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Figure 17. Number of visits per test site within the Australian Capital Territory and upper
Murrumbidgee Catchment 2003-2010 (visits per site are categorized as 1-5, 6-10,11-15 etc). .......... 22
Figure 18. Proportion of reference sites in the Australian Capital Territory within each AUSRIVAS
O:E score band 2003-2010. ................................................................................................................... 23
Figure 19. Proportion of test sites in the Australian Capital Territory within each AUSRIVAS O:E
score band 2003-2010. ......................................................................................................................... 23
Figure 20. Percentage of sites sampled within each habitat and season in the Australian Capital
Territory and upper Murrumbidgee Catchment for each macroinvertebrate taxonomic richness
category. ............................................................................................................................................... 24
Figure 21. Summary of AUSRIVAS assessments based on O:E scores for all river sites sampled in
Victoria (numbers refer to AWRC basins). ............................................................................................ 25
Figure 22. Number of visits per reference site within Victoria 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 26
Figure 23. Number of visits per test site within Victoria 2003-2010 (visits per site are categorized
as 1-5, 6-10,11-15 etc). ......................................................................................................................... 26
Figure 24. Proportion of reference sites in Victoria within each AUSRIVAS O:E score band 20032010. ..................................................................................................................................................... 27
Figure 25. Proportion of test sites in Victoria within each AUSRIVAS O:E score band 2003-2010.27
Figure 26. Percentage of sites sampled within each habitat and season in Victoria for each
macroinvertebrate taxonomic richness category. ................................................................................ 28
Figure 27. Summary of AUSRIVAS O:E scores for all river sites surveyed in Tasmania (numbers
refer to AWRC basins). .......................................................................................................................... 30
Figure 28. Number of visits per reference site within Tasmania 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 31
Figure 29. Number of visits per test site within Tasmania 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 31
Figure 30. Proportion of reference sites in Tasmania within each AUSRIVAS O:E score band 20032010. ..................................................................................................................................................... 32
Figure 31. Proportion of test sites in Tasmania within each AUSRIVAS O:E score band 20032010…………………………………………………………………………………………………………………………………………………32
Figure 32. Percentage of sites sampled within each habitat and season in Tasmania for each
macroinvertebrate taxonomic richness category. ................................................................................ 33
Figure 33. Summary of AUSRIVAS O:E scores for all river sites surveyed in the Northern Territory
(numbers refer to AWRC basins). ......................................................................................................... 35
Figure 34. Number of visits per reference site within the Northern Territory 2003-2010 (visits per
site are categorized as 1-5, 6-10,11-15 etc).......................................................................................... 36
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Figure 35. Number of visits per test site within the Northern Territory 2003-2010 (visits per site
are categorized as 1-5, 6-10,11-15 etc). ............................................................................................... 36
Figure 36. Proportion of reference sites in the Northern Territory within each AUSRIVAS O:E
score band 2003-2010. ......................................................................................................................... 37
Figure 37. Proportion of test sites in the Northern Territory within each AUSRIVAS O:E score
band 2003-2010. ................................................................................................................................... 37
Figure 38. Percentage of sites sampled within each habitat and season in the Northern Territory
for each macroinvertebrate taxonomic richness category................................................................... 38
Figure 39. Summary of AUSRIVAS O:E scores for all river sites surveyed in South Australia
(numbers refer to AWRC basins). ......................................................................................................... 40
Figure 40. Number of visits per reference site within South Australia 2003-2010 (visits per site
are categorized as 1-5, 6-10,11-15 etc). ............................................................................................... 41
Figure 41. Number of visits per test site within South Australia 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 41
Figure 42. Proportion of reference sites in South Australia within each AUSRIVAS O:E score band
2003-2010. ............................................................................................................................................ 42
Figure 43. Proportion of test sites in South Australia within each AUSRIVAS O:E score band 20032010. ..................................................................................................................................................... 42
Figure 44. Percentage of sites sampled within each habitat and season in South Australia for
each macroinvertebrate taxonomic richness category. ....................................................................... 43
Figure 45. Summary of AUSRIVAS O:E scores for all river sites surveyed in Western Australia
(numbers refer to AWRC basins). ......................................................................................................... 44
Figure 46. Number of visits per reference site within Western Australia 2003-2010 (visits per site
are categorized as 1-5, 6-10,11-15 etc). ............................................................................................... 45
Figure 47. Number of visits per test site within Western Australia 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc). ..................................................................................................... 45
Figure 48. Proportion of reference sites in Western Australia within each AUSRIVAS O:E score
band 2003-2010.. .................................................................................................................................. 46
Figure 49. Proportion of test sites in Western Australia within each AUSRIVAS O:E score band
2003-2010. ............................................................................................................................................ 46
Figure 50. Percentage of sites sampled within each habitat and season in Western Australia for
each macroinvertebrate taxonomic richness category. ....................................................................... 47
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Acknowledgements
The authors, project officers at the Department of Sustainability, Environment, Water, Population
and Communities and 2011 State of the Environment Committee thank the following organisations
for contribution of AUSRIVAS data to this project:
ACT Department of Territory and Municipal Services
ActewAGL
ALS Water Resources Group
Department of Environment and Conservation, Western Australia
Department of Environment and Resource Management, Queensland
Department of Natural Resources Environment & the Arts, Northern Territory
Department of Primary Industries, Parks, Water and Environment, Tasmania
Environment Protection Authority, South Australia
EPA Victoria
Kosciuszko Thredbo Ltd
New South Wales Department of Environment and Climate Change, and
New South Wales National Parks and Wildlife
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Key Findings

Over two thirds (68%) of reference sites assessed using the Australian River Assessment
System (AUSRIVAS) were assessed as more biologically diverse than reference condition
or had similar biological diversity to reference condition, and were therefore likely to be
to still be minimally disturbed and in reference condition. However, 32% of reference
sites sampled were significantly impaired or severely impaired. It is expected that <10%
of reference sites will be significantly impaired. Therefore it needs to be investigated
whether many of these significantly and severely impaired reference sites are still
suitable reference sites for AUSRIVAS assessments.

Just over half (54%) of the test sites assessed using AUSRIVAS were either more
biologically diverse or had similar biological diversity to reference condition, and were
therefore likely to be in good ecological condition or ‘health’. The results also show that
the remaining test sites had lost between 15 and 100% of macroinvertebrate taxa
expected to occur under undisturbed or natural conditions. This indicates that many test
sites are showing the effects of human and environmental pressures.

The number of visits to individual reference and test sites varied nationally In
Queensland, New South Wales, Victoria and the Northern Territory the majority of
reference and test sites were assessed between 1 and 5 times during 2003-2010.
Whereas in the Australian Capital Territory, Tasmania, South Australia and Western
Australia more than half or all of the reference sites and test sites (only in Western
Australia) were assessed six or more times during 2003-2010.

Compared to the 2006 and 2001 State of The Environment (SoE) assessments the
percentage of significantly impaired sites has increased from 31% in 2001 and 33 % in
2006 to 40% in this report. Severely impaired sites decreased slightly to 6% from 9% in
2006. It should be noted that AUSRIVAS results between reporting cannot be strictly
quantitatively compared because of variations in the locations and rationale for site
locations between reporting periods.

Within each state and territory there was evidence of human and environmental
pressures on macroinvertebrate communities at test sites sampled during 2003-2010.
The percentage of impaired test sites across all states and territories ranged from 25% to
75%. Queensland (25%) and the Northern Territory (30%) had the lowest percentage of
impaired sites. While Victoria (60%) and the Australian Capital Territory (75%) had the
highest percentage of impaired sites.

Queensland, New South Wales, Victoria, Tasmania and the Northern Territory collected
more macroinvertebrate taxa at sites during this assessment period than the Australian
Capital Territory, South Australia and Western Australia. This result may indicate that
relatively more sites sampled in this assessment period in the Australian Capital
Territory, South Australia and Western Australia were under greater pressures from
human activity, fire and/or drought than in other states. Alternatively, the differences
between states and territories in taxonomic richness may result from the different
reasons for targeted sampling of certain locations and the various objectives for the
states and territory assessment programs.

This assessment uses data from non-randomly selected sites that were sampled during
2003-2010 and often selected for targeted sampling. Thus, the sampling is not fully
spatially representative of the condition of river networks, but rather of the set of river
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
reaches of interest to the state and territory agencies at the time of sampling. This
sampling bias is substantially less for some areas (e.g. Victoria and The Murray Darling
Basin) than others.

In some regions the proportion of the sites sampled during 2003-2010 for the 2011 SoE
differs from earlier SoE reporting periods. Therefore, the results are not truly
representative of changes in condition through time. There is a clear need for a national
standardised spatially randomised sampling framework if AUSRIVAS assessments are to
be truly representative of changes and condition at a national scale through time. A
spatially randomised sampling framework that is representative at the catchment scale
is currently only operating in the Murray Darling Basin and Victoria.
1 Introduction
1.2 Using AUSRIVAS to measure in-stream biological health
AUSRIVAS (Australian River Assessment System) uses riverine aquatic macroinvertebrate data to
provide information about river health using nationally standardised methods and analysis
protocols. Aquatic macroinvertebrates are a diverse range of insects, crustaceans and mollusks,
which include snails, water boatmen, dragonflies, stoneflies, mayflies and aquatic worms. They are
generally visible to the naked eye, are an important source of food for fish and platypus and are
involved in ecosystem processes such as nutrient cycling. They are also widespread, easy to sample,
relatively immobile, and most importantly, the number and type of macroinvertebrates at a site can
reflect environmental changes that influence the stream ecosystem during several months before
sampling. Therefore, they provide an ‘integrated’ indicator of human effects on the stream
ecosystem.
The definitions of terms commonly used in AUSRIVAS assessment are given in Table 1.
Table 1. Definitions of terms used in AUSRIVAS assessment.
Term
Site
Test site
Reference site
Reference condition
O:E score
Taxonomic richness
Definition
A location of a river where macroinvertebrate sampling takes place in a
habitat (e.g. edge or riffle). For AUSRIVAS this is a river reach defined as
10 times bankfull width (minimum length 100m). Except Victoria where a
reach is defined as 10 times the average stream width, to a maximum of
150m (minimum length 50m).
An AUSRIVAS sampling site of unknown condition that may be subject to
human disturbance (e.g. water quality degradation, habitat degradation
or altered flow regimes).
An AUSRIVAS sampling site that is minimally disturbed by humans.
In-stream health expected to occur under undisturbed conditions
The number of expected macroinvertebrate taxa collected (observed)
divided by the number expected to occur at a site.
The number of different types of macroinvertebrates (mostly at family
level) collected in a sample.
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
AUSRIVAS river health assessment scores, referred to as the Observed:Expected score (O:E score),
are based on comparing the number of aquatic macroinvertebrate taxa observed at test sites to the
number expected to occur at the sites if they were undisturbed (i.e. in reference condition). The
number of macroinvertebrate taxa (identified to family level except worms and mites, which are
identified to class) expected at a site are predicted from data collected at a large set of ‘least
disturbed’ reference river sites with similar geographic and physical features to the test sites. The
value of the O:E score can range from zero (indicating that none of the expected taxa were found at
the site) to around one, with values close to one indicating that the site has a macroinvertebrate
community composition similar to that expected if the site was in reference condition and minimally
disturbed.
The O:E scores are assigned to bands that describe different levels of biological condition, ranging
from ‘richer than reference’ condition (containing more families than expected) to ‘extremely
impaired’ (containing very few of the expected families) (Table 2). These bands can be used to
provide a summary report of the overall condition and severity of impacts for various sites. The
AUSRIVAS bands, to which the O:E scores are assigned, can provide a nationally comparable instream health indicator that is responsive to a variety of impacts, including water quality
degradation, habitat destruction, and altered flow regimes.
1.2 2003-2010 State of The Environment (SoE) reporting of in-stream biological health
This 2011 SoE report provides an assessment of in-stream biological health that summarizes the
analysis and interpretation of the AUSRIVAS data, which:
1. Maps the AUSRIVAS O:E score band for sites within Australian river basins in each state and
territory;
2. Assesses macroinvertebrate taxonomic richness for those sites within each state and
territory;
3. Tabulates and graphs AUSRIVAS band classification for all sites assessed in each
state/territory and Australia;
4. Analyses and illustrates sampling intensity over time (from 2003) for each state and
territory;
5. Interprets results and identifies potential problem areas; and
6. Compares results with the 2001 and 2006 SoE reports on in-stream health using AUSRIVAS
data.
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Table 2. O:E score bands, description and interpretations used for AUSRIVAS reporting
Band
Band description O:E score interpretations
X
A
B
C
D
MORE
BIOLOGICALLY
DIVERSE THAN
REFERENCE
More families found than
expected. Potential biodiversity
hot-spot. Possible mild organic
enrichment.
SIMILAR TO
REFERENCE
Most/all of the expected families
found. Water quality and/or
habitat condition roughly
equivalent to reference sites.
Impact on water quality and
habitat condition does not result
in a loss of macroinvertebrate
diversity at the family taxonomic
level.
SIGNIFICANTLY
IMPAIRED
Fewer families than expected.
Potential impact either on water
quality or habitat quality or both,
resulting in loss of families.
Possibly lost up to 40% of
families.
SEVERELY
IMPAIRED
Many fewer families than
expected. Loss of
macroinvertebrate biodiversity
due to substantial impacts on
water and/or habitat quality.
Possibly lost up to 70% of
families.
EXTREMELY
IMPAIRED
Few of the expected families
remain. Extremely poor water
and/or habitat quality. Highly
degraded. Possibly lost up to
100% of families.
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
2 Data analysis
2.1 AUSRIVAS data
AUSRIVAS data collected between 2003-2010 by state and territory agencies was used to provide an
assessment of in-stream biological health for the 2011 SoE Report. Note that there are some
differences in sampling methods between states and territories, which may affect the
macroinvertebrate data and O:E scores.
The data provided included:
1. O:E scores for all sites sampled.
2. Macroinvertebrate taxa collected at sites.
3. Site locations (latitudes and longitudes)
4. Sampling dates and season
5. Classification of site as a reference or test site
6. Habitat sampled
Analysis has been conducted assuming that all data are correct as received from data providers.
For the analysis and mapping of the AUSRIVAS O:E scores, the reference sites were separated
from test sites, because otherwise it may be assumed that all sites were test sites, which would give
the impression that a high percentage of test sites are similar to reference condition (Band A). This
also enabled an assessment of reference sites, which should by definition be in a condition similar to
reference (Band A). Deviations from Band A may indicate a change in the reference
macroinvertebrate community and bring into question the suitability of the site as an ongoing
reference site .
2.2 Mapping AUSRIVAS data
AUSRIVAS data is typically collected across different seasons (e.g. autumn and spring) and from
different habitats (e.g. edge and riffle) to account for changes in macroinvertebrate communities
with season and within different habitats in a river. AUSRIVAS O:E scores can be calculated for single
seasons and also from combined seasons (to account for seasonal variability) for each individual
habitat. The AUSRIVAS O:E scores mapped in this report were calculated as an average for the entire
assessment period (2003-2010). Combined season O:E scores were used where available or if not
available the single season O:E scores were used. Where two habitats were sampled at a site (e.g.
edge and riffle) a conservative approach was used where the habitat with the O:E score furthest
from reference condition was used for the AUSRIVAS site assessment (i.e. worst case scenario). Sites
were mapped according to their AUSRIVAS biological-condition band classification (e.g. X, A, B, C, D).
2.3 Macroinvertebrate taxonomic richness
Macroinvertebrate taxonomic richness was analysed as the proportion of sites within defined
taxonomic richness categories (low taxonomic richness: 0-5 and 6-10 taxa; medium taxonomic
richness: 11-15 and 16-20 taxa; high taxonomic richness: 21-25 and >25 taxa) for each habitat and
season sampled within each state and territory.Taxonomic richness was analysed at all sites for each
habitat sample from each season to avoid any duplication if the data were aggregated and to
account for any seasonal patterns.
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
2.4 Data analysis limitations
Changes in AUSRIVAS O:E score, sampling intensity and macroinvertebrate taxonomic richness
over time throughout the assessment period were outside of the scope of this project and not
examined. Therefore, there is no interpretation provided on temporal changes in stream biological
condition or sampling intensity during the assessment period. Future analysis could examine trends
throughout the assessment period.
The selection of macroinvertebrate sampling site locations are not randomised or standardised
between SoE reporting periods which prevents quantitative comparisons with the 2001 and 2006
SoE Report AUSRIVAS results. Greater power would be obtained in the analysis of trends over time,
if direct comparisons were made between the results from the same sites in each sampling period.
Since the previous SoE reports, some of the AUSRIVAS models (e.g. some Victorian, Northern
Territory and Western Australian models) were updated to improve their sensitivity for detecting
impairment. The implication is that the interpretation of trend analysis between SoE assessments for
O:E scores could be confounded. For example, an improved model may now better detect
impairment, where the previously used, less sensitive, model may have assessed the site as similar
to reference (Band A). Thus, changes in the proportion of sites assessed as impaired and assigned to
the various bands of biological condition may simply be indicative of improved assessment ability
rather than a real change in river condition.
Mapping of AUSRIVAS O:E scores has only previously occurred in the 2001 SoE Report. Therefore,
mapping results are only compared with the 2001 SoE Report. Reference site condition also has not
been investigated by the 2001 and 2006 SoE assessments. Thus, changes in reference site condition
between assessment periods cannot be investigated.
Comparisons of macroinvertebrate taxonomic richness could not be made between SoE reporting
years because this analysis was not undertaken for previous SoE Reports. There is also no analysis of
the types of taxa occurring at sites, thus no diagnostic ability is possible regarding the sensitivity of
different taxa to particular disturbances (i.e. sensitivities of taxa to poor habitat and water quality).
3 Results and Interpretation
3.1 National
At a national scale, 460 reference sites and 3526 test sites were sampled from 2003 to 2010
(Tables 3 and 4).
AUSRIVAS assessments classed <1% of the reference sites as more biologically diverse than
reference (Band X), while approximately 68 % of the sites had macroinvertebrate diversity similar to
reference condition (Band A), 31% were significantly impaired (Band B) and 1% were severely
impaired (Band C) (Table 3; Figure 1). This result shows that, approximately 68% of reference sites
can still be considered to be minimally disturbed and in reference condition. However, 32% of the
reference sites sampled are no longer minimally disturbed and in reference condition. In AUSRIVAS
assessments it is expected that <10% of reference sites will be significantly impaired. It needs to be
investigated whether many of these significantly and severely impaired reference sites are still
suitable reference sites for AUSRIVAS assessments.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
AUSRIVAS assessments classed 3% of the test sites as more biologically diverse than reference
(Band X), while just more than half of the sites (51%) had macroinvertebrate diversity similar to
reference condition (Band A), 39% were significantly impaired (Band B), 6% were severely impaired
(Band C) and just 1% were extremely impaired (Band D) (Table 4; Figure 2). While over half of the
assessed sites were either more biologically diverse or had similar biological diversity to reference
condition the remaining sites have lost between 15 and 100% of the macroinvertebrate taxa that
were expected if the sites were in undisturbed or natural conditions.
Queensland, New South Wales, Victoria, Tasmania and the Northern Territory had the greatest
proportion of sites with medium to high macroinvertebrate taxonomic richness. The remaining
states (WA and SA) and territory (ACT) had a greater proportion of sites with low to medium
taxonomic richness (Figures 8, 14,26,32 and 38). This result may indicate greater human, fire or
drought pressures on a greater proportion sites that were sampled within this assessment period in
the Australian Capital Territory, South Australia and Western Australia (Figures 20, 44 and 50). The
differences between states and territories in taxonomic richness results may also reflect differences
between the states and territories in the reasons for sampling certain locations in stream systems.
The number of visits to individual reference and test sites varied nationally. In Queensland, New
South Wales, Victoria and the Northern Territory the majority of reference and test sites were
assessed between 1 and 5 times during 2003-2010 (see Section 3.2; Figures 4, 5, 10, 11, 22, 23, 34,
35). Whereas in the Australian Capital Territory, Tasmania, South Australia and Western Australia
where more than half or all of the reference sites and test sites (only in Western Australia) were
assessed six or more times during 2003-2010 (see Section 3.2; Figures 16, 17, 28,29,40,41, 46, 47).
Sites visited multiple times included those sampled for assessments in different seasons or sites that
were a part of a specific long-term regional assessment programs.
Table 3. Number of AUSRIVAS macroinvertebrate bioassessment reference site O:E scores classed
within each band of biological condition (all states and territories 2003-2010).
X
More biologically
diverse than
reference
A
Similar to
reference
condition
2
312
Number of sites per band
B
C
Significantly
Severely
impaired
impaired
141
5
D
Extremely
impaired
Total
all reference
sites
0
460
Table 4. Number of AUSRIVAS macroinvertebrate bioassessment test site O:E scores classed within each
band of biological condition (all states and territories 2003-2010).
X
More biologically
diverse than
reference
97
A
Similar to
reference
condition
1793
Number of sites per band
B
C
Significantly
Severely
impaired
impaired
1405
213
D
Extremely
impaired
Total
all test sites
18
3526
Australia ■ State of the Environment 2011 Supplementary information
8
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Australia
X
A
B
C
D
Figure 1. Proportion of reference sites across Australia within each AUSRIVAS O:E score band of biological
condition 2003-2010. Note that this figure represents sampling locations used for this report and is not
necessarily a true representation of the condition of the Australian streams as a whole. This figure also
cannot be strictly quantitatively compared to previous assessment periods because of variations in the
locations and rationale for the selection of site locations.
Australia
X
A
B
C
D
Figure 2. Proportion of test sites across Australia within each AUSRIVAS O:E score band of biological
condition 2003-2010. Note that this figure represents sampling locations used for this report and is not
necessarily a true representation of the condition of the Australian streams as a whole. This figure also
cannot be strictly quantitatively compared to previous assessment periods because of variations in the
locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
9
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.1.2 Comparison with 2001 and 2006 SoE results
The percentage of significantly impaired (Band B) test sites was 31% in SoE 2001, 33 % in SoE
2006 and 40% in SoE 2011 (Table 5). The percentage of severely impaired test sites (Band C)
decreased slightly to 6% in SoE 2011 from 9% in SoE 2006 (Table 5). The proportion of test sites
assessed as Band X, Band A and Band D was similar between the 2001, 2006 and 2011 reporting
periods (Table 5). The increase in the percentage of significantly impaired sites from SoE 2001 to SoE
2011 may indicate an increase in human pressures within catchments, or a greater focus by agencies
on targeted sampling of impaired sites for particular management purposes, or the effect of recent
fires or droughts, or a combination of all three.
Table 5. Comparison of test sites assessed using AUSRIVAS macroinvertebrate bioassessment within
each AUSRIVAS OE score band for SoE 2011, SoE 2006 and SoE 2001. Percentage (rounded to nearest whole
number) of the total number of sites for each assessment period is shown in brackets. Note that these
numbers cannot be strictly quantitatively compared because of variations in the locations and rationale for
site locations between assessment periods.
Period of
assessment
2003-2010
(SoE 2011)
1990–2004
(SoE 2006)
1994–1999
(SoE 2001)
Number of sites per band
B
C
Significantly
Severely
impaired
impaired
X
More biologically
diverse than
reference
A
Similar to
reference
condition
D
Extremely
impaired
Total
all test
sites
97 (3)
1795 (51)
1403 (40)
213 (6)
18 (1)
3526
195 (4)
2465 (52)
1556 (33)
433 (9)
56 (1)
4705
154 (4)
1702 (54)
963 (31)
254 (8)
39 (1)
3112
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2 State and Territory
3.2.1 Queensland
Throughout the assessment period 50 reference sites and 324 test sites were sampled in
Queensland (Figure 3). Sites were located in Northern Queensland, South-East Queensland coastal
catchments and in the Murray-Darling Basin catchments (Paroo, Warego, Condamine-Culgoa, Border
Rivers, Moonie River) (Figure 3). Of the reference and test sites that were sampled within the
assessment period the majority were sampled between 1-5 times (Figures 4 and 5). Two thirds (66%)
of macroinvertebrate communities sampled at reference sites in Queensland were similar to or
more biologically diverse than reference condition (Figure 6). The remaining reference sites were
reference sites were significantly impaired (32%) and severely impaired (Figure 6).More than three
quarters (80%) of macroinvertebrate communities sampled at test sites in Queensland were similar
to or more biologically diverse than reference condition (Figure 7). While approximately 20% of test
sites were either significantly or severely impaired (Figure 7). The edge habitats sampled had a
greater proportion (59% in autumn and 73% in spring) of sites with high taxonomic richness
compared to sites with riffle habitats (Figure 8).
A greater proportion of the impaired test sites were located in the South-East Queensland
coastal catchments and the Condamine-Culgoa, Border Rivers, Moonie River (Figure 3) compared
with other areas sampled in North Queensland. This may be a result of greater urban and
agricultural pressures in these areas. A comparison of results (i.e. the AUSRIVAS O:E scores) from
areas of Queensland sampled during the current SoE assessment period and the 2001 assessment
period indicates a similar assessment of in-stream biological health. Fewer sites were sampled in the
coastal and central regions of Queensland between 2003 and 2010 compared with the 2001 SoE
Report (Figure 3). Conversely, more sites have been sampled in the Paroo catchment between 2003
and 2010 compared to the 2001 SoE Report (Figure 3).
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 3. Summary of AUSRIVAS O:E scores for all river sites surveyed in Queensland (numbers refer to
Australian Water Resources Council [AWRC] basins).
Australia ■ State of the Environment 2011 Supplementary information
12
AUSRIVAS- Australia’s in-stream biological health 2003-2010
40
0
20
Number of sites
60
80
QLD
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 4. Number of visits per reference site within Queensland 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
200
150
100
0
50
Number of sites
250
300
QLD
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 5. Number of visits per test site within Queensland 2003-2010 (visits per site are categorized as 15, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
QLD
X
A
B
C
D
Figure 6. Proportion of reference sites in Queensland within each AUSRIVAS O:E score band 2003-2010. Note
that this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
QLD
X
A
B
C
D
Figure 7. Proportion of test sites in Queensland within each AUSRIVAS O:E score band 2003-2010. Note that
this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 8. Percentage of sites sampled within each habitat and season in Queensland for each macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
15
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.2 New South Wales
Throughout the assessment period 45 reference sites and 1265 test sites were sampled in New
South Wales (Figure 11). All of the reference and test sites that were sampled within the assessment
period were sampled between 1-5 times (Figures 12 and 13). Over half (58%) of macroinvertebrate
communities sampled at reference sites in New South Wales were similar to reference condition
(Figure 14). The remaining reference sites were significantly impaired (40%) and severely impaired
(2%) (Figure 14). More than half (60%) of the macroinvertebrate communities sampled at test sites
in New South Wales were similar to or more biologically diverse than reference condition (Figure
15). The remaining test sites had macroinvertebrate communities that were either significantly or
severely impaired (Figure 15). Most river systems in New South Wales showed evidence of human
pressures on macroinvertebrate communities. River systems within the highly urbanised Sydney
metropolitan area had significantly and severely impaired communities. These patterns of biological
impairment were consistent with the 2001 SoE assessment. Across all habitats and seasons sampled
>90% of sites sampled in New South Wales displayed either medium or high taxonomic richness in
summer, autumn, winter and spring (Figure 16). The alpine areas of the state in Kosciusko National
Park were also sampled in summer and winter in each year of the assessment period.
Figure 9. Summary of AUSRIVAS O:E scores for all river sites surveyed in New South Wales during 20032010 (numbers refer to AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
30
20
0
10
Number of sites
40
NSW
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 10. Number of visits per reference site within New South Wales 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
800
600
400
0
200
Number of sites
1000
1200
NSW
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 11. Number of visits per test site within New South Wales 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
NSW
X
A
B
C
D
Figure 12. Proportion of reference sites in New South Wales within each AUSRIVAS O:E score band 20032010. Note that this figure represents sampling locations used for this report and is not necessarily
representative of the whole state. This figure also cannot be strictly quantitatively compared to previous
assessment periods because of variations in the locations and rationale for the selection of site locations.
NSW
X
A
B
C
D
Figure 13. Proportion of test sites in New South Wales within each AUSRIVAS O:E score band 2003-2010.
Note that this figure represents sampling locations used for this report and is not necessarily representative
of the whole state. This figure also cannot be strictly quantitatively compared to previous assessment
periods because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 14. Percentage of sites sampled within each habitat and season in New South Wales for each macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
19
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.3 Australian Capital Territory
Throughout the assessment period, 24 reference sites and 66 test sites were sampled in and
around the Australian Capital Territory (ACT) in the upper Murrumbidgee River catchment (Figure
15). Over half of the reference sites were sampled 11 times or more with the assessment period
(Figure 16). The majority of test sites that were sampled within the assessment period were sampled
between 1-5 times (Figure 17). Over half (62%) of macroinvertebrate communities sampled at
reference sites in the Australian Capital Territory were similar to reference condition (Figure 18). The
remaining reference sites were significantly impaired (Figure 18). At approximately 75% of test sites
the macroinvertebrate communities sampled were either significantly or severely impaired (Figure
19). These test sites were located in agricultural and urban areas or on the regulated Cotter River
system. The location of sites and the degree of disturbance is reflected in the taxonomic richness,
with 40-62% of sites having low or medium taxonomic richness in both the edge and riffle habitats in
both autumn and spring (Figure 20). The low to medium taxonomic richness is more than likely the
result of agricultural, urban or regulation pressures at these sites. The AUSRIVAS assessment results
at many of the urban and agricultural sites are similar to the 2001 SoE assessment. However, in the
2001 SoE there were many more reference sites sampled as a part of the Monitoring River Health
Initiative and National River Health Program that were assessed as similar to reference condition in
the southern half of the ACT in the Namadgi National Park.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 15. Summary of site assessments based on AUSRIVAS O:E scores for all river sites sampled in the
Australian Capital Territory and upper Murrumbidgee Catchment (numbers refer to AWRC basins) during
2003-2010.
Australia ■ State of the Environment 2011 Supplementary information
21
AUSRIVAS- Australia’s in-stream biological health 2003-2010
6
4
0
2
Number of sites
8
ACT
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 16. Number of visits per reference site within the Australian Capital Territory and upper
Murrumbidgee Catchment 2003-2010 (visits per site are categorized as 1-5, 6-10,11-15 etc).
20
15
0
5
10
Number of sites
25
30
35
ACT
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 17. Number of visits per test site within the Australian Capital Territory and upper Murrumbidgee
Catchment 2003-2010 (visits per site are categorized as 1-5, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
22
AUSRIVAS- Australia’s in-stream biological health 2003-2010
ACT
X
A
B
C
D
Figure 18. Proportion of reference sites in the Australian Capital Territory within each AUSRIVAS O:E
score band 2003-2010. Note that this figure represents sampling locations used for this report and is not
necessarily representative of the whole ACT and upper Murrumbidgee catchment. This figure also cannot be
strictly quantitatively compared to previous assessment periods because of variations in the locations and
rationale for the selection of site locations.
ACT
X
A
B
C
D
Figure 19. Proportion of test sites in the Australian Capital Territory within each AUSRIVAS O:E score band
2003-2010. Note that this figure represents sampling locations used for this report and is not necessarily
representative of the whole ACT and upper Murrumbidgee catchment. This figure also cannot be strictly
quantitatively compared to previous assessment periods because of variations in the locations and rationale
for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 20. Percentage of sites sampled within each habitat and season in the Australian Capital Territory and upper Murrumbidgee Catchment for each
macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
24
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.4 Victoria
Throughout the assessment period, 265 reference sites and 1483 sites were sampled in Victoria
(Figure 21). All of the reference and test sites that were sampled within the assessment period were
sampled between 1-5 times (Figures 22 and 23). Two thirds (66%) of macroinvertebrate
communities sampled at reference sites in Victoria were similar to reference condition (Figure 24).
The remaining reference sites were significantly impaired or severely impaired (Figure 24).
Approximately 40% of macroinvertebrate communities sampled at test sites in Victoria were similar
to or more biologically diverse than reference condition (Figures 25). More than half (60%) of the
test sites sampled had macroinvertebrate communities that were either significantly (Band B),
severely (Band C) or extremely impaired (Band D) (Figure 25). Approximately 50% of all the sites
sampled had medium or high taxonomic richness in both the riffle and pool habitats in both autumn
and spring (Figure 26). Assessment of macroinvertebrate communities in central Victoria showed
some evidence of human or drought pressure with most communities being significantly impaired,
which is ssimilar to the 2001 SoE assessment (Figure 21). The less-developed river systems in the
Upper Murray, the Gippsland region and in the far west of the state showed minimal evidence of
human pressures with many sites similar to reference condition (Figure 21).
Figure 21. Summary of AUSRIVAS assessments based on O:E scores for all river sites sampled in Victoria
(numbers refer to AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
25
AUSRIVAS- Australia’s in-stream biological health 2003-2010
100
0
50
Number of sites
150
200
VIC
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 22. Number of visits per reference site within Victoria 2003-2010 (visits per site are categorized
as 1-5, 6-10,11-15 etc).
1000
500
0
Number of sites
1500
VIC
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 23. Number of visits per test site within Victoria 2003-2010 (visits per site are categorized as 1-5,
6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
26
AUSRIVAS- Australia’s in-stream biological health 2003-2010
VIC
X
A
B
C
D
Figure 24. Proportion of reference sites in Victoria within each AUSRIVAS O:E score band 2003-2010. Note
that this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
.
VIC
X
A
B
C
D
Figure 25. Proportion of test sites in Victoria within each AUSRIVAS O:E score band 2003-2010. Note that this
figure represents sampling locations used for this report and is not necessarily representative of the whole
state. This figure also cannot be strictly quantitatively compared to previous assessment periods because of
variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
27
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 26. Percentage of sites sampled within each habitat and season in Victoria for each macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
28
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.5 Tasmania
Throughout the assessment period, 41 reference sites and 204 test sites were sampled in
Tasmania (Figure 27). Half of the reference sites were sampled 21 times or more (Figure 28). While,
the majority of test sites that were sampled within the assessment period were sampled between 15 times (Figure 29). More than three quarters (84%) of macroinvertebrate communities sampled at
reference sites in Tasmania were similar to reference condition or more biologically diverse than
reference (Figure 30). The remaining reference sites reference sites were significantly impaired (12
%) and severely impaired (4%)(Figure 30).Approximately 50% of the macroinvertebrate communities
sampled at test sites in Tasmania were similar to or more biologically diverse than reference
condition (Figure 31). Conversely, the other 50% of test sites showed that macroinvertebrate
communities were either significantly, severely or extremely impaired (Figure 31). Approximately 6080% of the sites assessed had medium to high taxonomic richness in both the edge and riffle
habitats in autumn and spring (Figure 32). Similar to the 2001 SoE assessment in most river systems
assessed in Tasmania, the macroinvertebrate communities at 50% of sites showed some evidence of
human impacts with significantly and severely impaired macroinvertebrate communities. The northeast corner of the state has many sites assessed as similar to reference condition, especially in the
Piper and Ringarooma River catchments (Figure 27).
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 27. Summary of AUSRIVAS O:E scores for all river sites surveyed in Tasmania (numbers refer to
AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
30
AUSRIVAS- Australia’s in-stream biological health 2003-2010
15
10
0
5
Number of sites
20
TAS
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 28. Number of visits per reference site within Tasmania 2003-2010 (visits per site are categorized
as 1-5, 6-10,11-15 etc).
100
50
0
Number of sites
150
TAS
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 29. Number of visits per test site within Tasmania 2003-2010 (visits per site are categorized as 15, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
31
AUSRIVAS- Australia’s in-stream biological health 2003-2010
TAS
X
A
B
C
D
Figure 30. Proportion of reference sites in Tasmania within each AUSRIVAS O:E score band 2003-2010. Note
that this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
TAS
X
A
B
C
D
Figure 31. Proportion of test sites in Tasmania within each AUSRIVAS O:E score band 2003-2010. Note that
this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
32
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 32. Percentage of sites sampled within each habitat and season in Tasmania for each macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
33
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.6 Northern Territory
Throughout the assessment period, 16 reference sites and 57 test sites were sampled in the
Northern Territory (Figure 33). Data were only available for a few north-western river systems
(Elizabeth/Howard, Darwin/ Blackmore, Finness, Daly and Adelaide Rivers) (Figure 33). In these
north-western river systems the majority of test and reference sites were sampled 1-5 times (Figures
34 and 35). Almost all (94%) of macroinvertebrate communities sampled at reference sites in the
Northern Territory were similar to reference condition (Figure 36). Approximately 6% of reference
sites were significantly impaired (Figure 36). More than two thirds (70%) of test sites had
macroinvertebrate communities that were similar to or more biologically diverse than reference
condition (Figure 37). More than two thirds (70%) of all sites also had a high taxonomic richness
(Figure 38). The AUSRIVAS results and location of the sites for this assessment period was similar to
the 2001 SoE. In both 2001 and this assessment period the majority of sites sampled in the
Elizabeth/Howard, Darwin/Blackmore, Finness and Daly River catchments showed minimal effects of
human disturbance. In the assessment period for this SoE report only one site was sampled in the
Adelaide River catchment (in the south catchment) and it was significantly impaired (Figure 33). In
the 2001 SoE report many sites in the Adelaide River catchment were similar to reference condition.
With only one site collected for this assessment period there is insufficient information to assess if
the Adelaide River catchment has improved in condition since 2001.
Australia ■ State of the Environment 2011 Supplementary information
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AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 33. Summary of AUSRIVAS O:E scores for all river sites surveyed in the Northern Territory
(numbers refer to AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
35
AUSRIVAS- Australia’s in-stream biological health 2003-2010
8
6
0
2
4
Number of sites
10
12
NT
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 34. Number of visits per reference site within the Northern Territory 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
30
20
0
10
Number of sites
40
50
NT
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 35. Number of visits per test site within the Northern Territory 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
36
AUSRIVAS- Australia’s in-stream biological health 2003-2010
NT
X
A
B
C
D
Figure 36. Proportion of reference sites in the Northern Territory within each AUSRIVAS O:E score band
2003-2010. Note that this figure represents sampling locations used for this report and is not necessarily
representative of the whole territory. This figure also cannot be strictly quantitatively compared to previous
assessment periods because of variations in the locations and rationale for the selection of site locations.
NT
X
A
B
C
D
Figure 37. Proportion of test sites in the Northern Territory within each AUSRIVAS O:E score band 20032010. Note that this figure represents sampling locations used for this report and is not necessarily
representative of the whole territory. This figure also cannot be strictly quantitatively compared to previous
assessment periods because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
37
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 38. Percentage of sites sampled within each habitat and season in the Northern Territory for each
macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
38
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.7 South Australia
Throughout the assessment period, 49 reference sites and 46 test sites were sampled in South
Australia (Figure 39).River health was unable to be assessed in many South Australian catchments
using the AUSRIVAS protocol as many rivers are dry and ephemeral. Over half of the reference sites
were sampled 6 times or more within the assessment period (Figure 40). While the majority of test
sites that were sampled within the assessment period were sampled between 1-5 times (Figure 41).
More than two thirds (73%) of macroinvertebrate communities sampled at reference sites in South
Australia were similar to reference condition (Figure 42). Approximately 23% of macroinvertebrate
communities at reference sites were significantly impaired, 4% were severely impaired and more
biologically diverse than reference condition (Figure 42). More than half (55%) of the
macroinvertebrate communities sampled in South Australia were similar to or more diverse than
reference condition (Figure 43). The remaining sites had macroinvertebrate communities that were
either significantly or severely impaired (Figure 43). More than half (50-60%) of the sites sampled
had a medium taxonomic richness for both the edge and riffle habitats in autumn and spring (Figure
44). Eight sites sampled for this SoE assessment in the Murray Darling Basin were similar to
reference condition in this assessment (Figure 39). River systems with impaired macroinvertebrate
communities include, Diamantina River and Spencer Gulf Catchments as was found in the 2001 SoE
assessment (Figure 39). Recent drought may be a major factor causing the impaired conditions.
It should be noted that the current AUSRIVAS models used in South Australia need review and
possibly updating because some of the reference sites used to create the South Australian models
may have been more than minimally disturbed. Thus, the band representing ‘similar to reference’
condition is wide for the South Australian models. The implication for this is that the models may be
less sensitive than desired and may be detecting only gross disturbances, while more subtle
impairment may not be identified. As a result the overall assessment will produce too many sites
similar to reference condition (Band A). Currently, only the heavily disturbed sites or arid streams are
highlighted as impaired by the existing models.
Australia ■ State of the Environment 2011 Supplementary information
39
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 39. Summary of AUSRIVAS O:E scores for all river sites surveyed in South Australia (numbers refer
to AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
40
AUSRIVAS- Australia’s in-stream biological health 2003-2010
15
10
0
5
Number of sites
20
SA
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 40. Number of visits per reference site within South Australia 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
20
15
0
5
10
Number of sites
25
30
SA
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 41. Number of visits per test site within South Australia 2003-2010 (visits per site are categorized
as 1-5, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
41
AUSRIVAS- Australia’s in-stream biological health 2003-2010
SA
X
A
B
C
D
Figure 42. Proportion of reference sites in South Australia within each AUSRIVAS O:E score band 2003-2010.
Note that this figure represents sampling locations used for this report and is not necessarily representative
of the whole state. This figure also cannot be strictly quantitatively compared to previous assessment
periods because of variations in the locations and rationale for the selection of site locations.
SA
X
A
B
C
D
Figure 43. Proportion of test sites in South Australia within each AUSRIVAS O:E score band 2003-2010. Note
that this figure represents sampling locations used for this report and is not necessarily representative of the
whole state. This figure also cannot be strictly quantitatively compared to previous assessment periods
because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
42
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 44. Percentage of sites sampled within each habitat and season in South Australia for each macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
43
AUSRIVAS- Australia’s in-stream biological health 2003-2010
3.2.7 Western Australia
Throughout the assessment period, 12 reference sites and 39 test sites were sampled in
Western Australia (Figure 45). Data were only available for rivers in the South Western corner of the
state, and only from the channel habitat in spring. All test and reference sites sampled within the
assessment period were sampled between 6-10 times (Figures 46 and 47). Two thirds (66%) of
macroinvertebrate communities sampled at reference sites in Western Australia were similar to
reference condition (Figure 49).The remaining reference sites were significantly impaired (Figure 48).
Approximately 52% of macroinvertebrate communities sampled at test sites were similar to or more
diverse than reference condition (Figure 49). The remaining sites (48%) had macroinvertebrate
communities that were significantly impaired (Figure 49). Three quarters (75%) of all sites sampled
had a medium macroinvertebrate taxonomic richness (Figure 50). River systems that were affected
by human disturbance with significantly impaired sites include the Swan Coast, Murray River, Collie
River, Frankland River, Shannon River, Warren River, Donnelly River and Blackwood River.
Significantly, severely and extremely impaired sites were observed in many of these river systems in
the 2001 SoE assessment.
Figure 45. Summary of AUSRIVAS O:E scores for all river sites surveyed in Western Australia (numbers
refer to AWRC basins).
Australia ■ State of the Environment 2011 Supplementary information
44
AUSRIVAS- Australia’s in-stream biological health 2003-2010
8
6
4
0
2
Number of sites
10
12
WA
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 46. Number of visits per reference site within Western Australia 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
20
0
10
Number of sites
30
40
WA
0
5
10
15
20
25
30
35
40
45
50
55
Visits per site
Figure 47. Number of visits per test site within Western Australia 2003-2010 (visits per site are
categorized as 1-5, 6-10,11-15 etc).
Australia ■ State of the Environment 2011 Supplementary information
45
AUSRIVAS- Australia’s in-stream biological health 2003-2010
WA
X
A
B
C
D
Figure 48. Proportion of reference sites in Western Australia within each AUSRIVAS O:E score band 20032010. Note that this figure represents sampling locations used for this report and is not necessarily
representative of the whole state. This figure also cannot be strictly quantitatively compared to previous
assessment periods because of variations in the locations and rationale for the selection of site locations.
WA
X
A
B
C
D
Figure 49. Proportion of test sites in Western Australia within each AUSRIVAS O:E score band 2003-2010.
Note that this figure represents sampling locations used for this report and is not necessarily representative
of the whole state. This figure also cannot be strictly quantitatively compared to previous assessment
periods because of variations in the locations and rationale for the selection of site locations.
Australia ■ State of the Environment 2011 Supplementary information
46
AUSRIVAS- Australia’s in-stream biological health 2003-2010
Figure 50. Percentage of sites sampled within each habitat and season in Western Australia for each
macroinvertebrate taxonomic richness category.
Australia ■ State of the Environment 2011 Supplementary information
47