Water quality Information Sheet
Aquatic ecosystem condition reports
2014 panel assessment of creeks and drains from the South East NRM region
Issued July 2015
EPA 1073/15: This information sheet describes the outcome of the panel assessment of creeks and drains from the South East Natural Resources Management (NRM) region, sampled during autumn and spring 2014.
Introduction
The Environment Protection Authority (EPA) coordinates a monitoring, evaluation and reporting (MER) program on the aquatic ecosystem condition of South Australian creeks and rivers. This MER program is designed to meet several objectives:
• Providing a statewide monitoring framework for creeks and rivers that revolves through the NRM regions with sufficient frequency to allow for state-of-the-environment reporting.
• Describing aquatic ecosystem condition for broad general public understanding.
• Identifying the key pressures and management responses to those pressures.
• Providing a useful reporting format that supports environmental decision making within government, community and industry.
This information sheet provides a summary of the scientific work used in assessing monitoring data from drains, creeks and rivers. Aquatic ecosystem science is not always rigid and precise; it is often open to different interpretations in several respects. Therefore, the EPA has decided that the best way to assess the condition of streams is through an expert panel deliberation that uses a consistent descriptive modelling approach. The panel members comprised an environmental consultant and two biologists from the EPA (the authors of this assessment). All have at least 15 years’ experience in monitoring and assessing a range of streams across South Australia.
The panel members were:
• Peter Goonan, EPA
• Tracy Corbin, EPA
• Chris Madden, Freshwater Macroinvertebrates.
This information sheet is a technical document that contains relatively sophisticated concepts and content. It summarises the scientific assessment of data collected from creeks and drains found in the South East during 2014.
Environment Protection Authority
Aquatic ecosystem condition reports
Site selection
A total of 40 sites were sampled during autumn and spring 2014. Sites were largely selected from a list of previously sampled (fixed) sites throughout the region to ensure that the spatial extent of the stream network (mostly drains and a smaller number of creeks) accessible by roads was sampled. A new site was included from the lower reach of Drain M on request from the South East Wetlands Group, comprised of a consultative group of government representatives with an interest in wetland management, to extend the knowledge of a section of the drain where endangered Yarra Pygmy Perch occur.
This sampling design provides targeted information about the fixed sample sites and only gives an indication of the general condition of waters in each region. The lack of randomly selected sites limits the ability for this design to provide a statistically valid assessment of all waters in a region with some measure of known error (Stevens and Olsen 2004). The EPA has developed a reach database for South Australia (Catchment Simulations Solution 2011) which can be used to generate random sites from the stream network but this was not used to select sites from the South East in 2014.
The assessment
Members of the expert panel individually rated each site using a descriptive model for interpreting change in aquatic ecosystems in relation to increasing levels of disturbance (Davies and Jackson 2006). The assumption in this assessment is that biological (ecological) condition deteriorates as the degree of human disturbance in the catchment increases, and conversely, the best condition occurs where there is little to no human disturbance of the environment (Figure 1).
Figure 1 Human disturbance gradient showing the six different ecological condition grades or ratings ranging from Excellent (best) to Very Poor (worst) with a brief definition of each condition.
The process used to grade or rate sites involved the following steps:
1 A conceptual model describing the ecological responses to a general disturbance gradient was developed, reviewed and updated by the panel (Table 1).
2 Species lists were compiled which described the expected biotic assemblage for up to six potential condition ratings, based on the data collected in 2014 (Table 2).
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3 Each site was given a rating based on the macroinvertebrate communities, vegetation assemblages, water chemistry and sediment features that were recorded during the autumn and spring sampling periods. For sites that were consistently dry, only the vegetation data, sediment and habitat features were used to provide a rating; during wetter periods, at least some of these sites would probably rate differently but the assessment was based on the conditions that occurred during 2014.
4 The individual ratings derived by the panel members were combined to produce an overall, or final, rating for each site (Table 3).
The final reported ratings were derived by determining the mode rating (most common rating from the panel ratings for each site). In cases where the panel members disagreed and recommended three possible ratings, the final rating was determined by omitting the best and worst rating and selecting the middle rating. In the interests of being open and transparent about the final ratings derived in this process, all results have been included in Table 3 to show where the panel agreed or showed some difference in opinion.
The ratings in the model range from Excellent to Very Poor. However, given the extent of artificial drainage works and landuse modification that have occurred throughout most of the South East since European settlement, the panel considered that the Excellent and Very Good ratings probably no longer occur and were certainly not evident from the sites sampled in 2014.
2014 results
The overall condition rating for each site sampled in 2014 is in the table below.
Condition rating Total number of sites % sites
Excellent 0 0
Very Good 0 0
Good 2 5
Fair 16 40
Poor 21 52.5
Very Poor 1 2.5
TOTAL 40 100
The sites that were assigned with a Good rating included Eight Mile Creek and Piccaninnie Blue Lake Outlet; both are located in the lower South East between Port MacDonell and the Victorian border. They are permanently flowing, freshwater streams that provide habitat for many of rarer and more sensitive aquatic macroinvertebrates found in the region. They also support threatened fish and a wide range of aquatic plant species. Both streams showed the early signs of nutrient enrichment, including high nitrogen concentrations and presence of obvious growths of filamentous algae; Piccaninnie Blue Lake Outlet also had what appears to be an excessive growth of aquatic plants over more than 65% of the channel. It is possible that these streams, which are clearly significant biological refuges for the South East, may be damaged in the future if the high nitrogen loads recorded in 2014 are maintained or increased in the future, particularly if this coincides with any reduction on regional groundwater baseflows due to climatic drying events or water extractions in the supplying aquifers.
The Fair sites were mostly from the smaller coastal drains and creeks in the region. They included Picks Swamp Outlet Drain, Deep Creek and Jerusalem Creek in the Port MacDonnell area, several sites from Reedy Creek drain north from Millicent, sites from the lower reaches of Drain M near Beachport, Bray Drain and Drain L near Robe, and Henry Creek in
3 Aquatic ecosystem condition reports the upper South East near Tilley Swamp Conservation Park. All showed evidence of moderate nutrient enrichment, dominated by tolerant and generalist species and provided habitat for a few rare and sensitive species.
The Poor sites were located from the more salinised and ephemeral catchments throughout the drier inland and some coastal drains in the region. They included Hitchcox Drain in the Port MacDonnell area, drains that flow into Lake Bonney SE, Lake Frome North Drain and Narrow Neck Drain near Rendelsham, upper Drain M and Mosquito Creek, Blackford Drain inland from Kingston SE, Marcollat Watercourse and Didicoolum Drain in the upper South East, and sites from Naracoorte, Nalang and Tatiara creeks inland in the Naracoorte to Bordertown area. All showed evidence of gross nutrient enrichment, comprised tolerant and generalist aquatic species, and many were also affected by high salinity.
The only Very Poor site was Drain 57 downstream from the discharge from the paper and pulp mill. It was characterised by excessive nutrient enrichment, poor riparian and aquatic habitats, and presence of a sparse macroinvertebrate community, despite the presence of permanently flowing fresh water in this constructed drain. The biota and water chemistry were so different from that found from other streams in the region to warrant the rating for the site sampled in 2014.
Variability in panel member ratings
The results in Table 3 show that the expert panel members assigned the same condition rating to 20 sites (ie 50%) sampled from the region and the remaining sites only differed by one condition rating of each other. This indicates that there was considerable consistency for rating the sites using this approach and that the conceptual models provided an accurate representation of the range of stream types that occurred in the region in 2014.
It is important to note that it would be unrealistic to expect to obtain complete agreement in rating sites using an expert panel approach, or indeed any other means of integrating and reporting on measures of stream condition (eg classifying sites using indices or models using the reference-based concept, gradient analysis, comparisons against guidelines). This is due to the problems associated with separating groups along a continuum of possible groups, using environmental data that is inherently highly variable.
Multivariate analysis of the macroinvertebrate family level data from the wet sites sampled in 2009 and 2014 using canonical analysis of principal coordinates (CAP) showed a 90% agreement in the classification of sites by the final panel assigned ratings (EPA, unpublished data). Future assessments will incorporate more independent assessments of the data as part of the final expert panel means of rating site condition in a particular year.
Water chemistry of South Australian streams
Table 4 provides a statistical summary of the major chemistry and algal biomass (estimated using chlorophyll measurements) parameters taken at each of the wet sites in autumn and spring 2014.
The general water quality of streams and drains in the region based on median values indicated they were enriched with nitrogen, had moderate amounts of phosphorus, and were moderately fresh, well oxygenated and alkaline. Most parameters measured showed that the median and mean values were markedly different, indicating the data was strongly skewed by a small number of samples with particularly high chlorophyll, oxidised nitrogen, total phosphorus and conductivity concentrations.
The major difference between autumn and spring samples appeared to relate to the higher temperatures, conductivity and dissolved oxygen recorded in the warmer months when algal and plant productivity was high and flows had slowed or ceased in the majority of drains and streams in the area.
The South East lacks any undisturbed streams covered in remnant native vegetation that can provide a benchmark for the water quality that occurred in the region, prior to extensive changes to the drainage and natural vegetation and subsequent landuse modifications implemented across most of the landscape post European settlement. A complex network of straight artificial drains have been constructed to provide sufficient dry land for agricultural development to occur in the region.
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The only streams with natural channels are probably restricted to parts of several streams that drain into the state from western Victoria (eg Tatiara, Nalang, Morambro, Naracoorte, Yelloch and Mosquito creeks) and Henry Creek that ultimately drains into the southern Coorong but all have been significantly modified by their surrounding agricultural lands. Only Piccaninnie Blue Lake Outlet occurs entirely within a conservation park and Stony Creek, Lake Frome North Drain, drains in the Reedy Creek catchment and Mosquito Creek have part of their catchments within conservation parks; Eight Mile Creek also rises within the Ewens Pond Conservation Park but then flows through dairy grazing properties before discharging into the Southern Ocean. Several of the other streams sampled have patches of native vegetation in their catchments, including Picks Swamp Outlet Drain and Marcollat Watercourse but grazing and cropping are the dominate landuses.
To overcome the lack of suitable reference sites to indicate none to low levels of human disturbance affecting streams in an area, the USEPA (2000) has advocated using the 25th percentile of all data from a region to set water quality thresholds. These values are expected to represent the approximate tipping points where streams are likely to be at increased risk of being degraded by excess nutrients and other contaminants of interest. Using this approach, the data provided in Table 4 shows that the major water chemistry and algal biomass thresholds for the South East are likely to be:
Nutrients: Total nitrogen (TN) 0.9 mg/L Total phosphorus TP) 0.02 mg/L
Algal biomass: Chlorophyll a 2 µg/L
Stressors: Conductivity 1,005 µS/cm Dissolved oxygen 6.6 mg/L pH 8
Complementary analyses of a class of attached benthic algae called diatoms that were sampled from the same sites in autumn and spring 2014 showed that diatom species changes appeared to occur around a Total Phosphorus concentration of about 0.05 mg/L (Tibby et al 2015). It was however difficult to separate the effects of individual nutrients on diatom community structure because they co-varied with salinity and each other in the datasets generated in 2014. Further analyses will be carried out of the diatom and invertebrate data and compared against previously collected data from the region, in order to strengthen any possible water quality thresholds that show a significant shift in environmental condition and which could ultimately be used as targets for any watercourse rehabilitation works in the future.
Note that the 25th percentile values given above are comparable to the trigger values that were recently proposed for the protection of sensitive mayflies and stoneflies from South Australian waters (Corbin and Goonan 2010): TN 0.5 mg/L, TP 0.02 mg/L and conductivity 1,000 µS/cm. The nutrient concentrations are also similar to those listed in the scientific literature using the same statistical criterion (eg Chambers et al 2012 and Smucker et al 2013). Consequently, it is likely that future water quality targets aimed at enhancing aquatic inland waters will be comparable to the same general scale of nutrient and salinity thresholds described above.
Conceptual models
A central assumption of the conceptual model was that the high levels of nutrients (nitrogen and phosphorus) recorded from South Australian waterways originated from human activities in each catchment, rather than from some unknown natural source (eg NLWRA 2001). This is consistent with the general poor nutrient status of ancient Australian soils and the need for native plants to conserve and recycle nutrients, rather than allow the regular export of nitrogen and phosphorus from the land into streams, where the nutrients may eventually be deposited many kilometres away.
Consequently, it was assumed that historical and present animal grazing landuses and cropping activities since European settlement have contributed towards the nutrient enrichment that is now evident in most drains and streams in the region. This may be evident through measuring higher than expected concentrations of nutrients in water samples (eg TN> 0.9 mg/L or TP> 0.02-0.05 mg/L) and/or noting signs of enrichment due to the presence of particularly large growths of phytoplankton, filamentous algae and aquatic plants or presence of anaerobic sediments due to the oversupply of
5 Aquatic ecosystem condition reports organic matter. Under such conditions, a generalist assemblage of aquatic macroinvertebrates typically dominates because they are capable of exploiting the high plant productivity and tolerating occasional poor water quality that often occur in such waters. In contrast, few if any of the regionally rare, sensitive and/or habitat specialists would be expected to occur in such streams or drains, and never in large numbers. These types of enrichment responses have subsequently been incorporated into the conceptual model to represent the major biological and chemical patterns that occur in streams throughout South Australia and have been described in the scientific literature for well over 100 years.
Similarly, another assumption of the conceptual model is that the very high salinity of some inland streams has been caused, or at least exacerbated, by the extent of native vegetation clearance and its replacement by cropping and grazing practices, which has promoted the secondary salinisation of streams due to the inflow of shallow saline groundwater. High salinity has been recognised as a major factor for the loss of salt-sensitive species and creation of habitats that favour only the more salt-tolerant species to be able to colonise and complete their life-cycles.
Recent research indicates that most freshwater species are generally replaced by salt tolerant species when salinities exceed about 5,000−10,000 mg/L, and that different threshold effects are evident with different taxonomic groups (eg Nielsen et al 2008, Kefford et al 2011).
While it is possible that some natural watercourses that existed prior to European settlement and modification may have approached or exceeded this salinity range, particularly when drying, it was assumed as part of this assessment that the extensive landuse changes brought about by farming and drainage have mobilised more salt into each affected stream than would have occurred if the landscape had remained unchanged. Waters with a salinity at or above 5,000 mg/L represent a highly disturbed state in the conceptual model.
Dry sites
Finally, it should be noted that the ratings for dry sites in particular, may vary when water is present. This should, however, be considered within the broader context of the variability that will occur in any stream in response to differences in the frequency and timing of floods and droughts, differences in the distribution and abundance of stock and feral animals accessing stream reaches, and the many other biological, chemical and physical habitat changes that undoubtedly occur over time. Despite this, the ratings assigned in this report provide what are expected to be an accurate condition assessment of those sites sampled in 2014 using the conceptual model that was specifically developed for the South East.
Comparison against broad-scale condition assessment based on risk factors
While the above results describe the actual condition of sampled sites based on data collected in 2014, it is also possible to estimate the likely condition of streams based on existing map-based datasets. Appendix 1 outlines the Iier 1 expected condition rating for each site by examining a range of landuse, topographic and google map images which is based on the risk rating approached described by Bryce et al (1999).
The results from the Tier 1 assessment indicated that one site is expected to be in Very Good condition (Piccaninnie Blue Lake Outlet), 12 sites in Fair condition, 24 sites in Poor condition, and three sites in Very Poor condition (Drains 31 and 57, and Naracoorte Creek). Comparison against the actual condition scores showed that 60% of sites were the same as the expected rating and 40% differed.
References
Bryce SA, Larsen DP, Hughes RM and P Kaufmann 1999, ‘Assessing relative risks to aquatic ecosystems: A mid Appalachian case study’, Journal of the American Water Resources Association 35: 23−36.
Catchment Simulations Solutions 2011, Spatially balanced sampling site selection for streams in South Australia: Pilot project for Adelaide and Mount Lofty Ranges region, unpublished report to the EPA, Revision 2, May 2011.
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Chambers PA, McGoldrick DJ, Brua RB, Vis C, Culp JM and GA Benoy 2012, ‘Development of environmental thresholds for nitrogen and phosphorus in streams’, Journal of Environmental Quality 41: 7−10.
Corbin TA and PM Goonan 2010, ‘Habitat and water quality preferences of mayflies and stoneflies from South Australian streams’, Transactions of the Royal Society of South Australia 134: 5−18.
Davies SP and SK Jackson 2006, ‘The biological condition gradient: a descriptive model for interpreting change in aquatic ecosystems’, Ecological Applications 16: 1251−1266.
Kefford BJ, Marchant R, Schafer RB, Metzeling L, Dunlop JE, Choy SC and P Goonan 2011, ‘The definition of species richness used by species sensitivity distributions approximates observed effects of salinity on stream macroinvertebrates’, Environmental Pollution 159: 302−310.
National Land and Water Resources Audit 2001, Nutrient balance in regional farming systems and soil nutrient status, Final report NLWRA, September 2001.
Nielsen DL, Brock MA, Vogel M and R Petrie 2008, ‘From fresh to saline: a comparison of zooplankton and plant communities developing under a gradient of salinity with communities developing under constant salinity levels’, Marine and Freshwater Research 59: 549−559.
Smucker NJ, Becker M, Detenbeck NE and AC Morrison 2013, ‘Using algal metrics and biomass to evaluate multiple ways of defining concentration-based nutrient criteria in streams and their ecological relevance’, Ecological Indicators 32: 51−61.
Stevens DL Jr and AR Olsen 2004, ‘Spatially balanced sampling of natural resources’, Journal of the American Statistical Association, 99: 262–278.
Tibby J, Barr C and J Fluin 2015, Diatom composition of south-east South Australian creeks and drains. Unpublished report to the Environment Protection Authority, South Australia, March 2015.
USEPA 2000, Ambient water quality criteria recommendations, information supporting the development of state and tribal nutrient criteria, rivers and streams in nutrient ecoregion XIV, EPA_822-B-00-002, Office of Science and Technology, Office of Water, US Environmental Protection Agency, Washington DC.
Further information
Online legislation is freely available. Copies of legislation are available for purchase from:
Service SA Government Legislation Outlet Adelaide Service SA Centre 108 North Terrace Adelaide SA 5000
Telephone: 13 23 24 Facsimile: (08) 8204 1909 Website:
General information
Environment Protection Authority GPO Box 2607 Adelaide SA 5001
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Telephone: (08) 8204 2004 Facsimile: (08) 8124 4670 Freecall: 1800 623 445 (country) Website:
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Table 1 Conceptual model of ecological responses to a disturbance gradient in the South East NRM region
Rating Excellent Very Good Good Fair Poor Very Poor
Stressor As naturally occurs; Least impacted; also Best condition sites Moderate nutrient Gross nutrient Severely altered: description probably no longer probably no longer showing initial signs of enrichment: commonly enrichment: commonly downstream from present in the South present in the South enrichment: not common occuring in the South occuring in the South industrial discharges, East due to the East due to the extent of in the South East where East where many East where many recently constructed extent of wetland wetland drainage and constructed drains and drains and agricultural drains and agricultural drains and urban drainage and associated construction only a few natural creeks show creeks show high drains which provide associated of earthen drains, as well streams are located in enrichment effects. levels of enrichment limited habitat and construction of as the degree of an agricultural effects. poor water quality for
earthen drains, as vegetation clearance landscape. Most likely to ecosystem values to well as the degree of and modification from occur in small coastal be supported or to vegetation clearance widespread agricultural creeks and drains in the have established. and modification landuse. However, small lower South East. from widespread coastal creeks and agricultural landuse. drains in the lower South East with extensive catchments of native vegetation may demonstrate this condition on some occasions.
Biological Native assemblages Best of ‘what is left, least Typical assemblages for Impaired Degraded Severely degraded assemblages of plants and disturbed’ assemblages; least impacted streams; assemblages; assemblages; tolerant assemblages with few animals; usually with high richness; intolerants good richness; generalist generalists and and generalist species taxa and generally low many rare or and specialist taxa assemblage that tolerant taxa dominate dominate but numbers abundances; may sensitive species dominate abundances; includes at least some numbers which usually usually reduced, have large numbers of present; typically may include some rare and sensitive includes some very although 1−2 one tolerant taxon high Ephemeroptera, introduced species species; emerging abundant taxa; generalist taxa may be such as worms, Plecoptera and symptoms of stress in sensitive and rare present in high mosquito larvae, Trichoptera (EPT) relation to nutrients and taxa, if present, abundances; only 1−2 amphipods 9 Aquatic ecosystem condition reports
Rating Excellent Very Good Good Fair Poor Very Poor richness; no present in low fine sediments; at least present in very low rare or sensitive (Austrochiltonia) or symptoms of stress abundances. some remnant native numbers; usual species present in low midges (eg or introduced aquatic vegetation present in the absence of some taxa abundances or absent; Chironomus,
species present. catchment and near the expected for the often only few or 1−2 Procladius or Note that temporary watercourse. available habitats scattered trees in the Tanytarsus); can and ephemeral present; at least some catchment and on the include organic habitats may have a trees present in the banks. feeders from highly low EPT assemblage local catchment and polluted waters such but provide habitat on the banks. as rat-tailed larvae; for a rich group of vegetation often colonising insects entirely comprised (eg beetles, introduced species waterbugs and with little to no dipterans), with remnant native abundances of all vegetation. species generally low.
Water As naturally occurs; Best condition sites with Largely unremarkable Fair water quality with Poor water quality with Very poor water chemistry no human sources of associated water quality; water quality with at least generally saturated generally saturated quality with at least conditions contaminants high proportion natural some nutrients present dissolved oxygen dissolved oxygen one parameter at a present and pest features means waters at higher than expected (when sampled during (when sampled during toxicant concentration species not are well oxygenated and concentrations, coupled the day), at least one the day), nutrients that is likely to limit the impacting on water low in nutrients and with at least one plant nutrient present at high present at high aquatic diversity of a quality (eg nutrient turbidity. indicator showing concentrations and concentrations and stream; often very low enrichment, deposits emerging signs of high algal and higher high plant productivity dissolved oxygen and of waste with high enrichment effects (eg plant growths (eg evident at the site (eg may be saline and levels of hormones). chlorophyll a >10 ug/L, chlorophyll a >10 ug/L, usually chlorophyll a enriched in nutrients filamentous algae >10% filamentous algae >10 ug/L, filamentous but algal and plant cover and/or >10% cover and/or algae >10% cover and growth limited. macrophytes >35% macrophytes >35% macrophytes >35% cover) but site not cover) evident on cover most of the overwhelmed. occasions. time).
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Rating Excellent Very Good Good Fair Poor Very Poor
Physical Natural habitat and Near natural habitat and Good habitat structure Fair habitat structure Poor habitat structure Severe modifications habitat and flow patterns; no flow regimes; mostly well and flow patterns that and flow patterns that and flow patterns that to physical habitat and flow patterns extractions into farm vegetated catchments may include channelised may include artificial may include artificial flow patterns; un- dams or other uses; with few dams present; drains and/or coastal drains and modified drains and temporary natural flow patterns range of sediment range of sediment types streams; human channels of some streams; catchment due to abstraction or types present and present and not always activities have not coastal creeks; modifications likely to discharges; little to no not always anaerobic. caused an obvious loss catchment affect flow patterns; remnant native anaerobic. of riffle (flowing) habitats; development and anaerobic fine vegetation remaining; range of sediment types landuses likely to sediments usually cleared agricultural or present and not always affect flow patterns; present, except when urban sites; anaerobic anaerobic. anaerobic fine large algal growths fine sediments, rip-rap sediments usually occur and oxygenate or alien sediments present, except when the sediments. often dominate on the large algal growths margins of these occur and oxygenate drains or channelised the sediments. streams.
Human No obvious human No significant human Effects of human Point and diffuse Obvious point and/or Severe point and/or activities and disturbances but disturbances but may disturbance becoming source enrichment diffuse source diffuse source effects sources in the may include roads include some rural obvious; point sources effects evident; enrichment effects that may include catchment and sparse rural housing and roads; no may be present but do riparian zone not present; unbuffered toxicant responses; housing; no point point source discharges not dominate flows; good effective at mitigating channel with effects dominate water sources and diffuse and diffuse pollution not buffer zones and/or nutrients and fine ineffective or no quality and biological pollution not obviously affecting the riparian vegetation sediment typically riparian vegetation response with little detectable, largely aquatic ecosystem due present that help to entering these remaining other than signs of the original due to the extent of to the extent of native mitigate diffuse pollution streams. introduced grasses; waterway evident; un- vegetation vegetation surrounding effects from surrounding major changes to buffered channel that surrounding each each stream. landuses. catchment landuse has undergone stream. with little remnant extreme modifications vegetation remaining in an agricultural or and agriculture and/or urban setting. urban uses dominate.
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Table 2 List of biota expected to occur for each rating in the South East NRM region
Note: Excellent and Very Good grades are not expected to occur given the extent of drainage and landuse modification in the region; any Very Good site would be expected to have most of the species found from Good sites but also include a wide range of mayflies, caddisflies and probably a few stoneflies as well. Attributes listed follow the sequence described by Davies & Jackson (2006).
Attributes Good Fair Poor Very Poor
Attribute 1 Amphipoda Paracalliopidae; Amphipoda Paracalliopidae; Decapoda Geocharax; Fish None present Rare and/or Decapoda Euastacus bispinosus Decapoda Euastacus bispinosus and Galaxiella pusilla (Dwarf Galaxias) regionally endemic and Geocharax ; Fish Nannoperca Geocharax; Fish Galaxiella pusilla variegata (Ewens Pond Pygmy (Dwarf Galaxias) Perch)
Attribute 2 Ephemeroptera Offadens, Ephemeroptera Offadens, Ephemeroptera Atalophlebia; Fish None present Sensitive, rare or Thraulophlebia, Atalophlebia; Thraulophlebia, Atalophlebia; Southern Pygmy Perch vulnerable specialist Trichoptera Lingora and Trichoptera Lingora and taxa with narrow Taschorema; Diptera Taschorema; Diptera environmental Austrosimulium and Apsectrotanypus; Fish Southern requirements Apsectrotanypus; Fish Yarra Pygmy Pygmy Perch Perch, Southern Pygmy Perch
Attribute 3 Acarina Oxus; Mollusca Angrobia; Acarina Oxus; Mollusca Angrobia; Hemiptera Diplonychus None present Sensitive, Amphipoda Austrogammarus; Amphipoda Austrogammarus; ubiquitous taxa Decapoda Paratya; Diptera Decapoda Paratya; Hemiptera Dixidae; Coleoptera Aulonogyrus Diplonychus; Diptera Dixidae; Coleoptera Aulonogyrus
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Attributes Good Fair Poor Very Poor
Attribute 4 Mollusca Glyptophysa; Acarina Acarina Arrenurus, Piona, Eylais, Acarina Arrenurus, Piona, Eylais, Diptera Chironomidae Opportunistic or Arrenurus, Piona, Eylais, Oribatida; Oribatida; Mollusca Glyptophysa; Oribatida; Mollusca Glyptophysa; [Procladius, Chironomus (often in generalist taxa Decapoda Amarinus; Decapoda Amarinus; Ephemeroptera Cloeon, large nos)]; Coleoptera Ephemeroptera Cloeon, Ephemeroptera Cloeon, Tasmanocoenis; Trichoptera Necterosoma Tasmanocoenis; Trichoptera Tasmanocoenis; Trichoptera Notalina, Oecetis, Triplectides, Notalina, Oecetis, Triplectides, Notalina, Oecetis, Triplectides, Hellyethira; Odonata Hellyethira; Odonata Hellyethira, Ecnomus; Odonata Coenagrionidae (Ischnura), Coenagrionidae (Ischnura and Coenagrionidae (Ischnura and Lestidae (Austrolestes), Xanthagrion), Lestidae Xanthagrion), Lestidae Hemicordulia and Hemianax; (Austrolestes), Libellulidae (Austrolestes), Libellulidae Diptera Simulium and (Orthetrum, Diplacodes), (Orthetrum, Diplacodes), Chironomidae (Cricotopus, Hemicordulia and Hemianax; Hemicordulia and Hemianax; Diptera Procladius, Corynoneura, Diptera Simulium and Simulium and Chironomidae Chironomus, Tanytarsus, Chironomidae (Cricotopus, (Cricotopus, Cladotanytarsus, Dicrotendipes, Polypedilum); Thienemaniella, Cladotanytarsus, Procladius, Corynoneura, Hemiptera Naucoris congrex, Rheotanytarsus); Coleoptera Chironomus, Tanytarsus, Paraplea; Coleoptera Sternopriscus, Limnoxenus Dicrotendipes); Hemiptera Naucoris Sternopriscus, Necterosoma, congrex, Paraplea; Coleoptera Limnoxenus, Onychohydrus
Sternopriscus, Limnoxenus, Onychohydrus
Attribute 5 Turbellaria; Oligochaeta; Turbellaria; Oligochaeta; Mollusca Turbellaria; Oligochaeta; Oligochaeta (often in large nos); Tolerant taxa Decapoda Cherax; Amphipoda Coxiella; Decapoda Cherax; Mollusca Coxiella, Hydrobiidae; Amphipoda Austrochiltonia; Austrochiltonia; Diptera Anopheles, Amphipoda Austrochiltonia; Decapoda Cherax; Amphipoda Collembola Hypogastruridae; Culex; Hemiptera Microvelia Collembola Hypogastruridae, Austrochiltonia; Collembola Diptera Anopheles, Culex, Aedes, Isotomidae; Diptera Anopheles, Hypogastruridae, Isotomidae; Ceratopogonidae; Hemiptera Culex; Hemiptera Micronecta, Diptera Anopheles, Culex, Micronecta, Anisops Sigara, Anisops, Microvelia; Fish Ceratopogonidae and Ephydridae; Philypnodon grandiceps (Flathead Hemiptera Micronecta, Sigara, Gudgeon) Anisops, Enithares, Agraptocorixa, Microvelia; Fish Philypnodon grandiceps (Flathead Gudgeon)
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Attributes Good Fair Poor Very Poor
Attribute 6 Mollusca Physa, Potamopyrgus in Mollusca Physa, Potamopyrgus; Mollusca Physa, Potamopyrgus; Mollusca Physa; Fish Gambusia Non-endemic or low nos. Fish Gambusia. Fish Gambusia (rarely due to poor water quality). introduced taxa
Attribute 7 Initial enrichment patterns becoming Moderate enrichment patterns Gross enrichment patterns Algal and aquatic plant growth Ecosystem function evident and often extending over becoming evident with high algal and becoming evident with very high minimal due to poor water quality much of the watercourse. Usually aquatic plant growths extending over algal and aquatic plant growth and possibly a toxicant effect; low
TKN concentration high and either much of the watercourse; filamentous extending widely throughout productivity and high chlorophyll biomass over 10 ug/L, algae covers over 35% of the watercourse; filamentous algae decomposition rates evident; macrophytes or filamentous algae benthos on occasion; sediments covers much of the benthos on typically saline, water highly over 10% cover at the site, but not usually well aerated except when occasion; sediments well aerated enriched in nutrients; often overwhelmed by nutrient effects primary production periodically when plant growth high but when ephemeral waters. In exceptional (yet). declines following floods; water crashes occur may become circumstances when concentrated column nutrient concentrations sulphidic due to organic breakdown; sewage effluent enters waters the usually high. typically high nutrient phytoplankton biomass may be concentrations in the water despite very high but does not persist in high primary productivity. the receiving environment.
Summary of Moderate to high taxa richness due Moderate to high taxa richness due to Moderate to low species richness Low species richness and usually biological patterns to large numbers of tolerant and large number of generalist taxa and and usually at least one tolerant low abundances, although may evident for rating sensitive taxa. Vegetation usually includes some rare and taxon present in 100's to 1000's. In- get large nos of one pollution assemblages provide habitat sensitive species in low numbers. stream vegetation provides major tolerant taxa on occasion.
opportunities for many adult insects Scattered trees near water provide habitat complexity for adult insects Absence of in-stream and riparian to utilise. some limited habitat for adult insects to utilise. vegetation means no significant to utilise. habitat opportunities for many types of adult insect stages to utilise.
*Other taxa previously collected from region include rare and sensitive specialist species such as: • Ephemeroptera (mayflies): Atalophebia aurata from Bakers Range Drain in 1977; Ulmerophlebia pipinna from Cress Ck, Hitchcock Drain, Eight Mile Ck and Nousia fuscula from Eight Mile Ck in 1994−1995. • Plecoptera (stoneflies): Dinotoperla brevipennis from Eight Mile Ck; Dinotoperla evansi from a few locations in the region in the 1990s; Leptoperla primitiva from Eight Mile Ck; and Austrocerca tasmanica from Naracoorte Ck and Mosquito Ck in the 1990s. Note that stoneflies have not been collected from the region in 2009 or 2014.
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Table 3 Condition ratings given by each panel member and final overall rating for each of the 40 sites monitored in the South East NRM region during 2014
Note: Site codes indicate the year sampled. NRM region followed by the site number. Refer to the EPA website
1 denotes the habitats at each site eg dry sites, or if edge (E) or both edge and riffle (ER) aquatic habitats were present; results for each autumn and spring sampling period were separated by comma, so E, ER means edge was sampled in autumn and both edge and riffle were sampled in spring.
Site code Site name Habitats1 Very Good Fair Poor Very Final Good Poor rating
2014.SE34 Baker Range Drain, near Dry, Dry − − 3 − − Fair Mount Burr
2014.SE15 Benara Creek, Lake Bonney E, E − − − 3 − Poor SE
2014.SE02 Blackford Drain, near Kingston E, E − − − 3 − Poor SE
2014.SE17 Blackford Drain, near Mount E, E − − 1 2 − Poor Scott Conservation Park
2014.SE01 Bray Drain, near Lake Hawdon E, E − − 2 1 − Fair South
2014.SE30 Butchers Gap Drain, near E, E − − 1 2 − Poor Butchers Gap Conservation Park
2014.SE03 Deep Creek, near Riddock Bay E, E - 1 2 − − Fair
2014.SE33 Didicoolum Drain, near E, E − − − 3 − Poor Marcollat Hall
2014.SE29 Drain 31, Millicent E, E − − 1 2 − Poor
2014.SE11 Drain 44, near northern end of ER, ER − − 1 2 − Poor Lake Bonney SE
2014.SE19 Drain 57, near Snuggery E, E − − − − 3 Very Poor
2014.SE25 Drain at Bevilaqua Ford, south E, E − − 1 2 − Poor from Rendelsham
2014.SE32 Drain E, near Lochaber Dry, Dry − − − 3 − Poor
2014.SE40 Drain K, between Lucindale E, E − 1 2 − − Fair and Robe
2014.SE18 Drain L, near Robe E, E − − 2 1 − Fair
2014.SE23 Drain M, near Beachport E, E − − 2 1 − Fair
2014.SE08 Drain M, near Callendale Dry, Dry − − − 3 − Poor
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Site code Site name Habitats1 Very Good Fair Poor Very Final Good Poor rating
2014.SE39 Drain M, north-east from E, E − 1 2 − − Fair Beachport
2014.SE04 Eight Mile Creek, Riddock Bay E, E − 2 1 − − Good
2014.SE26 Glencoe Drain, south from E, E − − 2 1 − Fair Kalangadoo
2014.SE31 Henry Creek, south from the E, E − − 3 − − Fair Tilley Swamp Conservation Park
2014.SE35 Hitchcox Main Drain, near E, E − − 1 2 − Poor Brown Bay
2014.SE27 Jacky White Drain, near E, E − − − 3 − Poor Avenue Flat
2014.SE21 Jerusalem Creek, east from E, E − − 3 − − Fair Port MacDonnell
2014.SE20 Kingston Main Drain, south- Dry, Dry − − - 3 − Poor east from Kingston SE
2014.SE36 Lake Frome North Drain, near E, E − − 1 2 − Poor Southend
2014.SE28 Marcollat Watercourse at Jip E, E − − 1 2 − Poor Jip Waterhole, near Jip Jip
Conservation Park
2014.SE14 Marcollat Watercourse, near Dry, Dry − − 3 − − Fair Bimbimbi Swamp
2014.SE09 Mosquito Creek, Struan E, Dry − − - 3 − Poor
2014.SE12 Nalang Creek, near Olive Bank Dry, Dry − − 1 2 − Poor
2014.SE13 Naracoorte Creek, Naracoorte E, E − − − 3 − Poor
2014.SE37 Narrow Neck Drain, near E, E − − 1 2 − Poor Rendelsham
2014.SE05 Piccaninnie Blue Lake Outlet, E, E 1 2 − − − Good Piccaninnie Ponds Conservation Park
2014.SE38 Picks Swamp Outlet Drain, E, E − − 3 − − Fair west from Piccaninnie Ponds Conservation Park
2014.SE07 Reedy Creek−Mount Hope E, E − − 3 − − Fair Drain, near Hogan’s Lane Regulator
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Site code Site name Habitats1 Very Good Fair Poor Very Final Good Poor rating
2014.SE06 Reedy Creek−Mount Hope E, E − − 2 1 − Fair Drain, near Mullins Swamp
2014.SE24 Reedy Creek−Wilmot Drain, Dry, Dry − − 3 − − Fair near Reedy Creek Conservation Park
2014.SE10 Stony Creek, near eastern ER, ER − − 3 − − Fair edge of Lake Bonney SE
2014.SE22 Sutherland Drain, near E, E − − − 3 − Poor Beachport
2014.SE16 Tatiara Creek, east from Dry, E − − − 3 − Poor Bordertown
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Table 4 Water chemistry and algal summary statistics from sites sampled from each region during 2014 (units given are mg/L unless otherwise indicated)
Autumn (n=33 wet sites) Spring (n=32 wet sites) Combined Autumn + Spring (n=65 wet sites both seasons combined) Parameter
mean 25th 50th 75th mean 25th 50th 75th mean 25th 50th 75th percentile percentile percentile percentile percentile percentile percentile percentile percentile
Chlorophyll a 38.2 1.9 4.4 11.8 11.7 2.2 4.5 7.8 25.2 1.9 4.3 7.5 (ug/L)
Chlorophyll b 1.6 0.1 0.1 0.9 1.6 0.1 0.2 0.9 1.6 0.1 0.1 0.8 (ug/L)
Oxidised N (NOx) 0.7 0.0 0.1 0.6 0.6 0.0 0.0 0.3 0.7 0.0 0.0 0.6
Total Nitrogen 2.2 0.8 1.6 2.3 1.8 1.0 1.3 2.8 2.0 0.9 1.5 2.8
Total Phosphorus 0.11 0.02 0.03 0.10 0.20 0.02 0.03 0.04 0.16 0.02 0.03 0.06
Water 11.6 10.7 11.6 12.3 20.1 16.8 20.1 24.1 15.8 11.5 14.4 20.1 Temperature (ºC)
Conductivity 2,352 949 1,401 2,268 3,842 1,034 1,545 3149 3,085 1,005 1,471 2,793 (uS/cm)
Dissolved Oxygen 8.7 6.9 7.9 10.0 9.4 5.6 10.0 12.0 9.0 6.6 9.1 11.5
pH (pH units) 8.3 8.1 8.3 8.8 8.3 8.0 8.1 8.7 8.3 8.0 8.3 8.8
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Appendix 1 Tier 1 broad-scale assessment of relative risks from major stressors to rivers and creeks in South Australia
Introduction
The activities and actions of humans have altered the structure and function of most aquatic ecosystems in many different ways but particularly through landuse changes to the natural environment. Assessing the ecological condition of waters is a complex task and invariably involves an evaluation of the biota and environmental factors that have direct and indirect effects on biota (eg Fleeger et al 2003) at a scale relevant for the living organisms inhabiting waters and for people to be able to use for water management purposes.
In the past, most studies have generally focused on assessing the condition of the biota (eg Karr 1981, Karr and Chu 1997) while others have assessed individual stressors (eg nutrients cited in numerous publications by the US Geological Survey and USEPA since the 1990s onwards) or issues [eg cattle impacts by Silla (2005) or wider landuse impacts by Sponseller et al (2001)]. Integrative methods that provide an indication of the general condition of streams have not been widely used despite the obvious value in providing a rapid assessment of large numbers of stream reaches or catchments in a region or state.
Bryce et al (1999) proposed a process to provide a simple assessment of numerous catchments and classify them along a human disturbance gradient using coarse-scale data from a range of GIS layers, topographic maps, aerial photographs and previous data collected during site-based studies in the past. The results can be summarised into risk ratings that describe the likely type and degree of disturbance from human activities in the catchment area upstream from specific reaches and sites. This approach assumed that stream biota in a catchment with few disturbances was considered at low risk of impairment whereas biota in a watershed subject to multiple disturbances over larger areas was considered to be at high risk. Implicit in this assumption was that the lower risk sites had few signs of human use and occupation, changes subject to agriculture and pastoral grazing were at an intermediate level of disturbance (Miserendino et al 2011) and that the high-risk sites were from urbanised streams or streams receiving point source discharges from industry.
Using a modified version of the example described by Bryce et al (1999), this report describes the development of a stressor matrix for each region and the way different criteria were used to assign a broad-scale (Tier 1) assessment of the likely condition of sampled sites using remotely collected data.
Methods
Sites and their watersheds covering the entire catchment upstream from the GPS sampling point on each waterway were delineated using GIS. A range of data was then compiled for each site using topographic maps, satellite and aerial photograph images available on Google maps, and landuse data summarised into areal estimates for each upstream catchment to confirm the probable presence of major human stressors (eg houses, roads and mines) relating to catchment landuses. Some disturbance measures such as road density and landuse statistics were based on quantitative data whereas others such as the presence of houses and mines were visually estimated from either satellite, topographic maps or based on previous field studies and experience from sampling in each region.
The approach of Bryce et al (1999) was modified to include the major risk attributes relevant to the South Australian landscape and focused on rating those activities that influenced or altered natural vegetative cover, channel morphology, sedimentation and chemical loading of streams found in each respective region.
For the southern part of the State (eg Mount Lofty Ranges, Murraylands, Fleurieu Peninsula, Kangaroo Island, South East and Eyre Peninsula) the major human landuses include large areas of agricultural cropping and grazing, residential development in rural and urban settings, vineyards, irrigated crops and some native and pine plantation forestry. Many streams in these areas have been incised and channelised due to historical vegetation clearance and the effects from urbanisation and stormwater flows. Only a few retain more than 50% of the original native vegetative cover; the latter all lie in conservation parks or largely inaccessible coastal areas that were unsuitable for clearing and subsequent cropping or grazing uses.
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The South East is unusual because there are naturally only a few streams that occur in a region that has been artificially dried by a large network of drains installed in the past. The few natural streams include four that originate in western Victoria and discharge to swamps and drains in the Bordertown to Naracoorte area, and a few coastal streams in the Port MacDonnell to Glenelg River area that have also been subjected to variable degrees of channelisation and modification to help support largely dairy grazing practices in the local area.
For the more arid parts of South Australia which include the Flinders Ranges and Lake Eyre Basin the extent of human uses of the landscape are more diffuse, and most towns and settlements are located on major road networks well away from streams. A range of cropping activities occurs in the southern Flinders Ranges, largely in the Willochra catchment but elsewhere the major landuse involves grazing natural vegetation. Sheep and cattle are grazed in the Flinders Ranges with pastoral cattle grazing dominating in the Far North around the Lake Eyre Basin.
The most notable towns or settlements situated near named creeks in the Far North include Crystal Brook, Gladstone, Melrose, Pekina, Quorn, Wilpena, Leigh Creek and Arkaroola in the Flinders Ranges and Oodnadatta from the Western Lake Eyre Basin and Innamincka from the Eastern Lake Eyre Basin. A number of abandoned mines occur in the region, particularly throughout the Flinders Ranges, but the most significant mines that are currently being worked and are located near regularly flowing streams occur in the vicinity of Leigh Creek. Otherwise, numerous rural houses are widely distributed across the region from the limited road network that occurs within the Flinders Ranges and both sides of the Lake Eyre Basin. The western part of the State lacks surface streams and only a few intermittent streams are located in the Mann and Musgrave ranges in the northwest of South Australia.
Scoring the stream sites
The information and data collected from each site in each sampled region was used to assign a risk index score that ranged from A = excellent to F = Very Poor, to correspond to the gradient from minimal to highest risk of disturbance or impairment used for other reporting purposes. Each score was an integration of information from the regional, catchment and reach scales that summarised the type and degree of disturbance upstream from the sample sites that were subsequently evaluated in the field.
Climate, geological, geomorphic and soil features were included, where appropriate, to provide a broad characterisation of the effects of temperature, rainfall, flow and sediment properties on the stream network present in the regions of interest. Particular attention was placed on the climatic patterns when sampling occurred, to allow some consideration of average, below or above average rainfall and subsequent flow patterns on stream sites to be assessed in any particular year. The number and intensity of upstream and streamside landuses were then considered relative to the expected conditions in each region. The expectation was that aquatic biota in catchments with few disturbances were likely to be at a low risk of impairment whereas biota in catchments subjected to many disturbances over large areas were considered to be at a high risk.
The stressor matrix derived for each year, dating from 2008−2014, shows how the criteria were used to assign scores to sampled sites and their catchments, which due to the large spatial scale sampled invariably represented the full disturbance gradient that was expected in each region. The risk attributes are aligned in rows on the left side of the matrix and were ranked from lowest to most severe when moving from the top to the bottom of the matrix. The complete list of sites and their Tier 1 risk scores for each year are reported as part of the Aquatic Ecosystems Condition Reporting program; the results from the 40 sites included in the South East in 2014 are provided in Table 1.
The process of deriving the Tier 1 risk ratings involved assessing the presence of positive risk attributes (naturalness features, limited human disturbance), zero attributes for ‘swing’ features that can alter a score from an A to a B, or an E to a D, and minus attributes that indicate significant human activities in a catchment. Consequently, sites located in protected areas with no human disturbance and only + attributes were rated A; sites with mostly + and a few 0 scores were rated B; those with mostly + and 0 scores and perhaps a – score were rated C; sites with mostly 0 and a few – scores were rated D; sites with mostly – and a few 0 scores rated E; and the worst rating of F was given to highly disturbed sites with only – scores. Not all attribute categories were relevant to all sites, so only those that related to each specific site and its’ catchment were considered.
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Summary
This coarse assessment can be made from any site planned to be sampled and is designed to provide a pragmatic first- cut assessment of the likely condition of a stream given the landuse modifications that have occurred over the last 170 years since European settlement. The expectation is that much of the landscape has been changed over time due to the extent of agricultural development that has occurred in what is essentially a flat and undulating terrain, so few streams would retain their completely original natural characteristics. Indeed, given the extent of cropping and grazing landuses throughout much of South Australia, few streams would be expected to be assigned to the A and B ratings, and most would show variable evidence of nutrient enrichment and fine sediment impacts which would place them in the C−E ratings on a six-scale rating system. Only the most heavily polluted and disturbed streams should be assigned to the poorest F rating, and would generally be expected to occur in major urban streams or downstream from an industrial point-source discharge.
These broad patterns are captured by this stage of the assessment to provide an expected condition score using remotely collected data. The results are then compared against the actual ratings from detailed sampling of the biology, chemistry and physical properties of stream sites using data collected during autumn and spring surveys to confirm whether the observed condition matches the expected condition, or is markedly different and subsequently requires further work to understand why any discrepancy exists. Both the condition ratings from the expected (Tier 1) and observed (Tier 2) assessments are reported against, and more detailed studies of specific catchments or water quality issues are reported separately as part of a Tier 3 program.
References
Bryce SA, Larsen DP, Hughes RM & PR Kaufmann 1999, ‘Assessing relative risks to aquatic ecosystems: A mid- Appalachian case study’, Journal of the American Water Resources Association 35: 23−36.
Fleeger JW, Carman KR & RM Nisbet 2003, ‘Indirect effects of contaminants in aquatic ecosystems’, The Science of the Total Environment 317: 207−233.
Karr JR 1981, ‘Assessment of biotic integrity using fish communities’, Fisheries 6: 21−27.
Karr JR & EW Chu 1997, Biological monitoring and assessment: using multimetric indexes effectively, EPA/235/R97/001, University of Washington, Seattle, Washington.
Miserendino ML., Casaux R, Archangelsky M, Di Prinzio CY, Brand C & AM Kutschker 2011, ‘Assessing landuse effects on water quality, in-stream habitat, riparian ecosystems and biodiversity in Patagonian northwest streams’, Science of the Total Environment 409: 612−624.
Silla A 2005, Effect of cattle grazing on benthic macroinvertebrate communities in the Kalgan River System, south-west Western Australia, Summary report of BSc Honours Thesis from the University of Western Australia, Department of Water, Western Australia.
Sponseller RA, Benfield EF & HM Valett 2001, ‘Relationships between landuses, spatial scale and stream macroinvertebrate communities’, Freshwater Biology 46: 1409−1424.
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