Lindsay Creek, Eringa Waterhole
2012 Aquatic Ecosystem Condition Report
- Permanently wet, non-flowing, waterhole when sampled in autumn 2012
- Moderately diverse macroinvertebrate community with several regionally rare and sensitive species collected
- Water was very fresh, clear and moderately enriched with nutrients
- Riparian vegetation consisted of native trees and shrubs and at least one aquatic plant
About the location
Lindsay Creek is a small stream that rises just inside the South Australian border in the Far North of the State and flows in a south-easterly direction, before discharging into Stevenson Creek. Further downstream, Stevenson Creek merges with Hamilton Creek and then Alberga River to form the Macumba River, which eventually discharges into the northern part of Lake Eyre North during very wet years. The major land use in catchment is cattle grazing. The monitoring site was located off a track from Oodnadatta to Albminga, about 22 km south-west from Albminga and 160 km north from Oodnadatta.
The creek was given a Good rating because the site sampled showed evidence of relatively minor changes in ecosystem structure and function. There was evidence of human disturbance including slight nutrient enrichment effects but the waterhole provides habitat for a number of rare and sensitive aquatic macroinvertebrates, a submerged plant and up to four native fish species.
A moderately diverse community of at least 16 species of macroinvertebrates was collected from the non-flowing, isolated waterhole, 50 m wide and over 1 m deep, in autumn 2012. The community was dominated by large numbers of waterbugs (Micronecta gracilis) and baetid mayflies (Cloeon), and included smaller numbers of mites (Unionicola), freshwater prawns (Macrobrachium), chironomids (Coelopynia, Larsia, Nanocladius, Cladotanytarsus, Tanytarsus, Parachironomus, Polypedilum and Dicrotendipes), caddisflies (Triplectides australis and Oecetis), dytiscid beetles (Necterosoma dispar) and a waterbug (Agraptocorixa parvipunctata). Several species are regionally significant because they are either rare (e.g. the mite Unionicola and midge Coelopynia), restricted to freshwater habitats (e.g. the beetle Necterosoma dispar and midges such as Larsia and Nanocladius) or considered to be sensitive but widely distributed species (e.g. Cloeon). The only typical riverine species collected were the prawns whereas the other species generally frequent still-water pool habitats. Adult dragonflies were seen at the site but no larval stages were collected from the waterhole. Large numbers of zooplankton were recorded, including both copepods and cladocerans. A few hardyhead fish (presumably Lake Eyre Hardyhead) were also collected from the waterhole.
The water was very fresh (salinity of 52 mg/L) and similar to rainwater salinity, well oxygenated (102% saturation), clear, and with generally moderate concentrations of nutrients such as nitrogen (0.7 mg/L) and phosphorus (0.04 mg/L).
The sediments were dominated by clay and detritus, with smaller amounts of silt, algae and sand also present; samples taken from below the surface were anaerobic grey clays and silts that are probably lacking in oxygen when the waterhole is drawing down due to evaporative losses over summer. Past flood damage has caused bank erosion over about 10% of the site but there was no evidence of any recent damage caused by cattle accessing the waterhole. The waterhole has, however, obviously been regularly visited by campers in the past due to presence of tracks on the banks in places.
A moderate to large growth of phytoplankton was present (chlorophyll a 12.6 Âµg/L) which included a small amount of blue-green algae or cyanobacteria (chlorophyll b 1.2 Âµg/L). Over 10% of the shallow margins of the waterhole were covered by a filamentous alga (Cladophora) and a similar area was covered by a submerged aquatic plant (Myriophyllum). The riparian vegetation was dominated by gum trees and acacias on the poorly vegetated banks (25-49% vegetative cover). The surrounding vegetation at the site comprised gums, acacias and scattered native shrubs and grasses.
Special environmental features
Eringa Waterhole provides an important refuge habitat for many regionally significant aquatic species of macroinvertebrates, at least one native fish species, and supports a near natural vegetation assemblage that includes at least one submerged native plant based on the sampling carried out in autumn 2012. An additional three native fish species (e.g. Desert Rainbowfish, Bony Bream and Spangled Perch) were also recently collected from the waterhole during fish surveys carried out in December 2011 and March 2012 as part of the Lake Eyre Basin Rivers Assessment (Cockayne et al. 2013), indicating that the waterhole supports a rich fish community in the upper reaches of the Macumba River catchment. This waterhole is probably one of the most natural stream environments in the region and should be listed as a significant environmental asset.
Pressures and management responses
|Livestock in the catchment are exerting some grazing pressure on vegetation and adding nutrients to the watercourse.||The SA Arid Lands Natural Resources Management Board recognizes that both direct and diffuse impacts on aquatic ecosystem condition can occur through direct stock access and excessive grazing pressure from stock and feral herbivores. Technical advice and incentives are offered to land managers in the region, as funding permits, to address these impacts through appropriate activities suitable for the context. In addition, projects are underway across the region to identify, prioritise and address impacts at key aquatic sites.|
|Recreational camping near the waterhole may be causing erosion, contributing to litter and weed dispersal.||The SA Arid Lands Natural Resources Management Board acknowledges the impact of uncontrolled tourism on private lands in the region, particularly where priority aquatic are subject to frequent camping visits. A trial is currently underway for an assessment tool which describes cultural, ecological and social features associated with aquatic sites as well as identifying impacts and prioritising management interventions, such as fencing and interpretive signage. In addition, an education program targeting the tourism industry is being planned, funding dependent, to help improve understanding of ecological impacts and to raise awareness about more appropriate, lower-impact behaviours|