Kanappa Creek, near Kanappa Hill
2010 Aquatic Ecosystem Condition Report
- Dry in autumn and consisted of an isolated, freshwater pool in spring.
- Sparse macroinvertebrate community with no rare or sensitive species.
- Obvious signs of gross nutrient enrichment.
- Riparian vegetation mostly consisted of woody and herbaceous weeds.
About the location
Kanappa Creek is a very small stream in the eastern Mount Lofty Ranges. It rises near Kanappa Hill and flows in a south-easterly direction but disappears underground before joining Saunders Creek. The major land uses are sheep grazing and native vegetation.
The monitoring site was located on a track off Three Chain Road, less than one kilometre south-east of Kanappa Hill and about nine kilometres south-west of Cambrai.
The creek was given a Poor rating because the site sampled showed evidence of major changes in ecosystem structure and moderate changes to the way the ecosystem functions. There was considerable evidence of human disturbance, including nutrient enrichment, fine sediment deposition and a degraded riparian zone.
A sparse community of about 16 species of macroinvertebrates was collected from an isolated pool, six metres wide and over one metre deep in spring 2010; the site was dry in autumn. The community consisted of low numbers of a wide range of species that are typically found in temporary waters with generally poor water quality, including hydrobiid snails, worms, mites, beetles, mosquitoes, biting midges, soldierflies, chironomids, waterbugs, odonates and caddisflies. No sensitive or rare species were found.
The water was moderately fresh (salinity of 1,975 mg/L), well oxygenated (84% saturation), clear and slightly acidic (pH 6.48), with moderate to high concentrations of nutrients such as nitrogen (0.9 mg/L) and phosphorus (0.05 mg/L).
The sediments were dominated by detritus with clay, silt, sand and algae also present; samples taken from below the surface showed no indications that the sediment was lacking in oxygen. A deposit of 1–5 centimetres of silt covered the creekbed in spring.
A moderate amount of phytoplankton was present in the creek and less than 10% of the site was covered by filamentous algae (Cladophora). Over 65% of the channel was covered by submerged (Chara) and emergent aquatic plants (Juncus and Typha).
The riparian zone consisted of acacias and introduced pepper trees and willows over an understorey of introduced grasses, thistles, gorse, saltbush and sedges. The surrounding vegetation included acacias, melaleucas and pepper trees with a groundcover of introduced grasses and weeds.
Special environmental features
Pressures and management responses
|Livestock have direct access at the site and upstream, causing sediment erosion and adding excessive nutrients (which leads to habitat disturbance, algal growth and aquatic weeds).
|The SA Murray–Darling Basin NRM Board 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.
|Limited riparian vegetation at the site and upstream, providing minimal buffer protection from catchment landuses (reducing habitat quality).
|The SA Murray–Darling Basin NRM Board recognises that the management of riparian vegetation requires a long-term, integrated approach to achieve ecosystem benefits. The board therefore provides free technical advice on a range of topics for land managers and various incentives for works as funding permits.
|Widespread introduced trees and weeds in the riparian zone at the site and upstream in the catchment (reducing habitat quality).
|The SA Murray–Darling Basin NRM Board recognises the limitations of available funds relative to the scale of the degradation caused by introduced trees and weeds. The NRM Board 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. The NRM Board actively seeks funding opportunities for weed control; most opportunities are for locations where biodiversity outcomes can be achieved.