Drought and reduced water flows contributed to emerging signs of nutrient enrichment.
Relatively minor changes to animal and plant life.
Creek provides important habitat for many threatened fish species and significant insect species.
Area map
About the location
Tookayerta Creek rises south of Mount Compass on the Fleurieu Peninsula, and flows east where it discharges into the Finniss River. Most of the catchment is devoted to livestock grazing (60%), with some dairying (18%) and areas of forestry and native vegetation (14%) also prominant. There are also small pockets of urban development, vineyards and horticulture.
The monitoring site was located in the lower reaches, upstream from Winery Road at Currency Creek.
The creek was given a Good rating at this site because the ecosystem showed relatively minor changes to its animal and plant life. There were clear signs of nutrient enrichment as a result of reduced flows during the drought. However, it is likely this section of the creek would rate better during wetter seasons when a more diverse community of plants and animals would be expected.
Findings
The creek was a narrow, dry channel lined with tall reeds when it was inspected in December 2008. Dried green filamentous algae (Cladophora) covered the site and couch grasses and aquatic plants such as Common Reed (Phragmites australis) and Water Ribbons (Triglochin procerum) grew across more than 90% of the channel.
The sediments were mostly sands and silts; they showed no evidence of being anaerobic or sulfidic below the surface, which indicates a generally good condition, capable of supporting a wide range of species sensitive to pollution.
Extensive areas of rushes (Juncus) grew over spikerush (Eleocharis acuta) and grasses (e.g.Paspalum) in the riparian zone. There was a notable lack of trees in the swamp habitat adjacent to the waterway; in fact little original vegetation remained in the surrounding landscape, which was planted to cereal crops and vines.
Special environmental features
None detected at the site sampled from the lower reaches of the creek in 2008.
However, Tookayerta Creek is one of the few streams in South Australia that usually flows for most of the year and during the recent drought from the mid to late 2000's, flow was sustained throughout the mid reaches of the stream. This part of the catchment is particularly important because it supports at least three threatened fish species (e.g. Southern Pygmy Perch, River Blackfish, and Mountain Galaxias) and several significant macroinvertebrates, including mayflies (Tasmanophlebia and Nousia fuscula), stoneflies (Leptoperla tasmanica and Austrocerca tasmanica) and predatory caddisflies (Taschorema evansi and Ulmerochorema membrum).
Pressures and management responses
Pressures
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.
Drought (reducing ecological integrity.
The SA Murray–Darling Basin NRM Board is working with the Department for Water and the community to develop a water allocation plan and licensing system which aim to balance social, economic and environmental needs for water. The objective for providing water to the environment is to maintain and/or restore self-sustaining water-dependent ecosystems which are resilient in times of drought.