Indicator: IW-30 Macroinvertebrate condition
Data
| Total length of reach (km) in each category and percentage of total in parentheses | Percentage of total length with data | ||||
|---|---|---|---|---|---|
| Reference | Significantly impaired | Severely impaired | Extremely impaired | ||
| Queensland | 9 334 (80) | 1 997 (17) | 250 (2) | 16 (1) | 16 |
| New South Wales | 11 366 (50) | 7 551 (34) | 2 801 (13) | 690 (3) | 38 |
| Australian Capital Territory | 169 (64) | 76 (29) | 17 (7) | 0 (0) | 97 |
| Victoria | 9 347 (76) | 2 447 (20) | 344 (3) | 49 (1) | 77 |
| Tasmania | 4 248 (75) | 1 097 (20) | 142 (3) | 100 (2) | 100 |
| South Australia | 7 866 (83) | 1 098 (12) | 124 (1) | 389 (4) | 98 |
| Western Australia | 4 401 (64) | 1 977 (29) | 419 (6) | 31 (1) | 27 |
| Northern Territory | 2 063 (88) | 247 (10) | 47 (2) | 0 (0) | 11 |
| Total | 48 793 (69) | 16 490 (23) | 4 144 (6) | 1 275 (2) | 34 |
Source: National Land and Water Resources Audit 2001, Australian Catchment, River and Estuary Assessment 2002, Volumes 1 and 2, Land and Water Australia, Canberra, viewed 15 Nov 2005, http://audit.ea.gov.au/ANRA/coasts/docs/estuary_assessment/River_Findings.cfm.
River condition, Queensland
Source: Department of Natural Resources and Mines 2004, Priorities in Progress report 2003-4: A clean, liveable and healthy environment, Queensland Treasury, viewed 23 Nov 2005, http://www.treasury.qld.gov.au/office/knowledge/docs/priorities/2003-04/subsections/clean_livable_healthy.pdf.
| Number of sites at each level of diversity compared with reference sites | ||||||
|---|---|---|---|---|---|---|
| Period of assessment | More diverse | Similar to reference condition | Significantly impaired | Substantially impaired | Severely impaired | Total number of test sites |
| 1990-2004 | 195 | 2 465 | 1 556 | 433 | 56 | 4 705 |
| 1994-99 (in SoE2001 ) | 154 | 1 702 | 963 | 254 | 39 | 3 112 |
Source: Department of the Environment and Heritage 2003, Australian River Assessment System ( AusRivAS), National River Health Database, Department of the Environemnt and Heritage.
Interim Indicator: River Health River Condition - Sites per AusRivAS Band (Interim NRHP River Health Assessment, all states and territories, 1990 - 2004)
Source: Australian River Assessment System (AusRivAS) 2005, National River Health Database, viewed 23 Nov 2005.
What the data mean
One-third (21 909 km) of river length is impaired to some degree (has lost between 20% and 100% of the various kinds of aquatic invertebrates that should live there). New South Wales has the poorest aquatic biota condition; approximately 50% of river length has impaired aquatic biota
In Queensland, the percentage of sites considered to be in a condition similar to reference decreased from 2001 to 2002, while the percentage of sites considered to be significantly impaired has increased.
The national Australian River Assessment System (AusRivAS) data show a significant number of sites that are more impaired than the reference sites.
Data Limitations
Assessment results are underestimates of change in some parts of the country, including the lowland rivers of the Murray-Darling Basin and Western Australia, where reference sites used as benchmarks have already been modified to some extent since European settlement.
Many of the sites sampled in Queensland in the two years are different and therefore the results may reflect differences between catchments and climatic variability between years.
The error margin or confidence intervals for AusRivAS indices have not as yet been precisely quantified.
All data are presumed to be correct as received from data providers. AusRivAS results depict only the most recent combined season score furthest from reference condition, where available (or the single season habitat score furthest from reference condition where a combined season score is not available) recorded during the assessment period.
Issues for which this is an indicator and why
Inland Waters - Response of biota - Macroinvertebrates
As well as being an indicator of river condition, macroinvertebrate populations are an important aspect of freshwater biodiversity in their own right. Their condition is readily measured because they are widespread, easy to sample and relatively immobile.
Other indicators for this issue:
Inland Waters - Habitat scale influences - In-stream habitat - woody debris and sand slugs
Macroinvertebrates are widespread, easy to sample, relatively immobile, and most importantly, their composition reflects the historical impact of environmental changes on the stream ecosystem for up to several months before sampling. They therefore provide an ‘integrated’ indicator of human impact on the stream ecosystem.
Other indicators for this issue:
- IW-13 Catchment sediment load
- IW-18 Exceedance of suspended solids water quality triggers
- IW-24 Extent of sedimentation (incl sand slugs)
- IW-25 Number and extent of re-snagging programs
Biodiversity - Species, habitats and ecological communities - Conservation status of species and ecological communities
Aquatic macroinvertebrates are a diverse group of animals that include a range of insect, crustacean and molluscan groups such as snails, water boatmen, dragonflies, stoneflies, mayflies and aquatic worms. As well as being an indicator of river condition, macroinvertebrate populations are an important aspect of freshwater biodiversity and ecological communities in their own right. Their condition is readily measured because they are widespread, easy to sample and relatively immobile.
Other indicators for this issue:
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
- BD-04 Listed threatened species or ecological communities for which recovery action is showing stable or increasing populations
- IW-31 Fish - Abundance and distribution
- IW-32 Frogs - Abundance and distribution
- IW-33 Abundance and distribution of waterbirds
- CO-01 Trends in selected groups of coastal and marine species and habitats
- CO-02 Number of marine species that are endangered or threatened and changes in population/ distribution of selected threatened species
- CO-16 Status of Australian fisheries
- LD-01 The proportion and area of native vegetation and changes over time
- AAT-08 Plankton populations
- AAT-09 Seabird populations
- AAT-10 seal populations
- AAT-11 Whale populations
- AAT-12 Changes in colonies of plants on Heard Island
Biodiversity - Species, habitats and ecological communities - Condition of freshwater biodiversity
Aquatic macroinvertebrates are a diverse group of animals that include a range of insect, crustacean and molluscan groups such as snails, water boatmen, dragonflies, stoneflies, mayflies and aquatic worms. Their composition reflects the historical impact of environmental changes on the stream ecosystem for up to several months before sampling. They therefore provide an ‘integrated’ indicator of human impact on the stream ecosystem.
Other indicators for this issue:
- IW-11 Number of licences dams, weirs, regulators and levees
- IW-27 Extent of significant wetlands (incl. Ramsar)
- IW-28 Number of effective fishways
- IW-29 Blue Green Algae
- IW-31 Fish - Abundance and distribution
- IW-32 Frogs - Abundance and distribution
- IW-33 Abundance and distribution of waterbirds
- IW-34 Examples of deterioration of condition of wetland vegetation
Further Information
- Australian Catchment, River and Estuary Assessment 2002
- Status of River Health in the Murray-Darling Basin
Key
Links to another web site
Links to data in the DRS
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