Locations
Fourteen sites were sampled from the Eastern Mount Lofty Ranges in autumn and spring 2015. These sites were located throughout the region between the Marne River in the north and the Finniss Creek catchment in the south; no sites were located on the largely saline Burra Creek in the northernmost part of the region. Rainfall patterns are dominated by winter rains and annual averages range from over 700 mm in the eastern hills and southern areas (e.g. Mount Barker, Kuitpo Forest, Mount Compass) to less than 300 mm on the plains near the River Murray (e.g. Black Hill). Land use is dominated by agriculture (grazing and dryland cropping) and also includes areas of irrigated vines and orchards, dairying, forests, urban areas, mines and remnant native vegetation. The generally low hills and flat plains of the Mount Lofty Ranges have been extensively cleared since European settlement, and only about 15% of the original vegetation remains (Environment Protection Authority 2008). The Eastern Mount Lofty Ranges has been particularly targeted for cropping and grazing uses and only about 8% of the original pre-European vegetation (e.g. grassland and grassy woodland communities) remains (O’Connor et al. 2008).
Key points
- The streams monitored included streams that discharge to the River Murray (Marne River), Murray plains (e.g. Dry Creek) or into the Lower Lakes region (e.g. Finniss, Angas and Bremer Rivers and catchments).
- No site was considered to be in Excellent, Very Good or Very Poor condition but three sites were in Good condition, five were Fair and six were in Poor condition.
- The better sites were from the Finniss River catchment on the Fleurieu Peninsula and the poorer sites were from the more ephemeral or saline streams from the Angas River, Bremer River, Dry Creek and Marne Creek catchments
- A few rare and sensitive aquatic species were recorded, particularly from sites in the Finniss River catchment Most streams were affected by nutrient enrichment
- Riparian zones often lacked trees and shrubs and were dominated by introduced weeds and grasses
Findings
Sites monitored in the Eastern Mount Lofty Ranges during 2015 were considered to be in Good to Poor condition. No sites were assigned to the Excellent, Very Good or Very Poor condition classes. Of the sites assessed, 3 (21%) were considered to be in Good condition with only minor changes to animal and plant life, 5 (36%) were considered to be in Fair condition, with moderate changes to animal and plant life, and some changes to the way the ecosystems functioned and 6 (43%) were considered to be in Poor condition, with evidence of major changes in the animal and plant life, and moderate changes to the way the ecosystems functioned.
The sites in Good condition included Finniss River near Yundi, Blackfellows Creek near Kyeema Conservation Park and Ti Tree Creek near McHarg Creek, all within the Finniss River catchment on the Fleurieu Peninsula. They all retained a high diversity of aquatic species and included some rare and sensitive species but showed signs of slight nutrient enrichment and some degraded vegetation within the riparian zone. The sites assessed in Fair condition included Deep Creek (Currency Creek catchment), Meadows Creek near Meadows (Finniss River catchment), and the Bremer River near Callington, Rodwell Creek west from Woodchester and Mount Barker Creek near Salem (all from the Bremer River catchment). These streams had a reduced range of aquatic species, had few rare or sensitive species and showed signs of moderate nutrient enrichment and degraded riparian zones. The Poor sites included the Marne River, near Cambrai, Dry Creek, near Monarto Zoo, and sites from the Angas River (Paris and Gould creeks) and Bremer River (Nairne and Western Flat creeks) catchments. These streams were located among agricultural and urban landscapes and were characterized by sparse to moderately diverse aquatic communities, obvious signs of gross nutrient enrichment and usually degraded riparian zones.
Most sites throughout the region showed evidence of nutrient enrichment (e.g. high concentrations of nitrogen and phosphorus recorded from each stream) either by the presence of large growths of filamentous algae, phytoplankton, and/or reeds and other types of aquatic plants. Many of the creeks and rivers had significantly disturbed riparian zones with cropping or other introduced grasses and weeds often being the dominant vegetation on the streambanks. Agricultural runoff carrying nutrients, and both sediment and bank erosion from stock damage, were also significant stressors affecting the condition of many streams in the region.
The aquatic macroinvertebrate communities of most streams were usually dominated by tolerant species such as an amphipod crustacean (Austrochiltonia), snails (introduced Physiella and Potamopyrgus, and native Glyptophysa), waterbugs (Micronecta, Microvelia and Anisops) and chironomids (Chironomus, Larsia, Paramerina, Tanytarsus and Dicrotendipes). Few rare and sensitive species were found in the region in 2015 but most were only recorded from the Finniss River catchment. They included mayflies (Atalophlebia australasica, Atalophlebia australis and Thraulophlebia inconspicua), stoneflies (Austrocerca tasmanicum, Riekoperla evansi, and probably small Dinotoperla evansi), caddisflies (Triplectides similis) and blackflies (Austrosimulium furiosum).
Special environmental features
A larger range of species was recorded from the region in 2010, when detailed assessments of 43 sites was carried out, and included rare and sensitive taxa that were not recorded in 2015 such as: an oniscigastrid mayfly from two sites on Tookayerta Creek, which only occurs in permanently flowing, sandy, freshwater streams on the Fleurieu Peninsula; a baetid mayfly (Offadens), blackfly (Paracnephia), chironomid (Eukiefferiella), waterbug (Hydrometra), damselfly (Nososticta solida), dytiscid beetles (Laccophilus sharpi and Limbodessus), stoneflies (Illiesoperla mayi and Leptoperla tasmanica), and several caddisflies (Taschorema, Ulmerochorema, Ethochorema hesperium, Orthotrichia bishopi, Atriplectides dubius, Notalina fulva, Lingora and Triplectides volda).
Previous sampling of streams from the Eastern Mount Lofty Ranges from the mid- 1990-2000’s collected a number of additional rare, sensitive and uncommon species that have not been recorded in the region during the past decade. They include a mite (Rhynchaustrobates bandus); beetles (Sclerocyphon and Simsonia); mayflies (Centroptilum elongatum and Nousia fuscula); stonefly (Newmanoperla thoreyi); caddisflies (Apsilochorema, Maydenoptila rupina, Hydroptila calcara, Hydroptila losida, Hydroptila scamandra, Oxyethira columba and Triaenodes); chironomids (Podonomopsis, Podonomus, Aphroteniella, Coelopynia pruinosa, Rheocricotopus, Gymnometriocnemus, Stempellina and Xenochironomus); dragonflies (Austrogomphus australis and Austrogomphus guerini); lacewing (Austroneurorthus); subterranean crustacean from the Family Parabathynellidae; and freshwater crab (Amarinus lacustris) which is more commonly found in the lower River Murray main channel, Lower Lakes and many coastal lakes in the South East.
The only threatened species of fish recorded during 2015 was the Mountain Galaxias (Galaxias olidus) which was seen at Ti Tree Creek in autumn in large numbers. In 2010, another threatened fish called the Climbing Galaxias (Galaxias brevipinnis) was recorded from four sites in the Finniss River catchment and previous fish surveys in the region have also noted the presence of threatened Yarra Pygmy Perch (Nannoperca obscura), Southern Pygmy Perch (Nannoperca australis) and River Blackfish (Gadopsis marmoratus) (Hammer 2009).
Pressures and management responses
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Pressures
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Management responses
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Livestock having direct access to some creeks, causing sediment erosion and adding excessive nutrients (which leads to habitat disturbance, algal growth and aquatic weeds).
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Natural Resources SA Murray–Darling Basin acknowledges the significant impacts that livestock have on aquatic environments and seeks to provide free technical advice and incentives to land managers for fencing and other works as funding permits. Funding incentives are limited in value and extent and require land managers to volunteer to be involved.
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Limited riparian vegetation at some creeks, providing minimal buffer protection from catchment landuses (reducing habitat quality).
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Natural Resources SA Murray–Darling Basin recognises that the management of riparian vegetation requires a long-term, integrated approach to achieve ecosystem benefits. The NRM Board therefore provides free technical advice on a range of topics for land managers and various incentives for works as funding permits.
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Insufficient natural water flows resulting from water extraction and climate variability (reducing ecological integrity).
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A water allocation plan that guides sustainable water use in the Eastern Mount Lofty Ranges has been developed by Natural Resources SA Murray–Darling Basin , working with the community and government (particularly the Department for Environment, Water and Natural Resources (DEWNR)). The plan aims to balance social, economic and environmental water needs and is implemented through a system of water licensing and permits for water affecting activities administered by DEWNR.
A key component of the water allocation plan is to provide water to sustain the environment at an acceptable level of risk. Securing low flows for the environment is a key environmental water provision in this area, and Natural Resources SA Murray–Darling Basin is working together with DEWNR, Natural Resources Adelaide and Mount Lofty Ranges and the community to develop a program to secure low flows across the Mount Lofty Ranges. For more information on water allocation planning and associated projects go to our Water Allocation Planning web page.
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Widespread introduced trees and weeds in riparian zones (reducing habitat quality).
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Natural Resources SA Murray–Darling Basin recognises the limitations of available funds relative to the scale of the degradation caused by introduced trees and weeds. It provides free technical advice and community education to assist land managers in dealing with the integrated management of aquatic weeds. The NRM Board also has a targeted process, as directed by state government, to strictly prioritise its investment in weed control activities as funds are limited. It actively seeks funding opportunities for weed control; most opportunities are for locations where biodiversity outcomes can be achieved.
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Stormwater runoff from some urban areas causing occasional high water velocities, containing nutrients and sediments (causing habitat disturbance, algal growth and aquatic weeds).
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Natural Resources SA Murray–Darling Basin is working closely with local government through various projects including: Strengthening Basin Communities, funded under the Water for the Future Program to develop Integrated Water Management Plans; the implementation of Water Sensitive Urban Design principles in development planning and conditions; encouraging the implementation of Best Practice Stormwater Management Guidelines. The NRM Board also administers the statutory requirements of the NRM Act relating to Water Affecting Activities.
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Further information
