Lake Eliza

 lake  Add category

 Upload a photo

Lake Eliza is a shallow hypersaline coastal lake in south-east South Australia, a region of winter rainfall and summer drought. It belongs to a series of coastal saline lakes (including Robe, St Clair and George) which have probably been formed as marine lagoons isolated from the sea by the formation of beachdune systems associated with the emerging coastline. Lake Eliza is below mean sea level and therefore acts as a local sink for groundwater. The groundwater flows from the surrounding dunes as well as from the underlying regional carbonate aquifer systems. There is an input of freshwater from the Robe Range aquifer to the east, but it is uncertain whether there is also an input from subsurface invasion of seawater. Natural springs and private drains flow into the lake with water only being removed through evaporation. The lake has a maximum depth of 1.4m which varies according to freshwater inflows, evaporation levels and possible sea water intrusion. Consequently the Lake is extremely saline, with salinities rising from three times that of seawater in winter to six times that of seawater in summer, with an accompanying fall in lake level. In autumn 1964 Lake Eliza dried up completely. Several small dune islands, composed of cemented sand size grains of limestone, occur in the southern section of the Lake. The shoreline of Lake Eliza consists of a salt marsh about 100m wide supporting an association of salt-loving plants. This area is inundated by high winter lake levels. Further away from the lake edges are highly modified introduced pastures interspersed with occasional clumps of rushes, sedges and saltwater tea tree. Several species of aquatic flowering plants, charophytes, green algae and blue-green algae are present. Invertebrate fauna in Lake Eliza include insects, crustaceans and molluscs. Waterbirds use the Lake at times, with the most common species being a variety of waders and ducks.

Statement of Significance:
The broad coastal plain of south-east South Australia and particularly the Lake Eliza region, provides an excellent location for the study of well preserved stratigraphic units formed by changes in sea level and coastal emergence. The group of saline lakes in the Beachport-Robe series (of which Lake Eliza is one) is also part of a larger selection of saline lakes in south-east Australia that are unusual in terms of accessibility, lake numbers and ranges of salinity. Lake Eliza itself is significant for a number of geological and faunal values. Halite precipitation and gypsum and carbonate formation are occurring, while the lakebed contains unique gelatinous sediments from the deposition of algae and fossilised mussel and oyster beds, formed during marine incursion. Also, algal mats have formed around the margins of springs on the lakebed, with evidence of formation of laminar structures similar to stromatolites. Information about the growth, morphology and constructing micro-organisms of these algal mats is of value to the understanding and interpretation of stromatolites and their habitats. The orange bellied parrot (NEOPHEMA CHRYSOGASTER) occurs on the edge of Lake Eliza and the Lake surrounds provide suitable habitat for this Nationally endangered species. The swamp antechinus (ANTECHINUS MINIMUS) has been recorded from near Lake Eliza and there are recent records from nearby Little Dip Conservation Park. The vegetation fringing Lake Eliza contains suitable habitat for this species which is listed as rare in South Australia. Lake Eliza has been the site of considerable geological research, as well as research into the chemical and faunal composition of its waters. The series of saline lakes to which Lake Eliza belongs has also been studied by tertiary and post-graduate limnology students.

It is possible that cultural values, both indigenous and non-indigenous, of National Estate significance may exist in this place. As yet, the Australian Heritage Commission has not identified, documented or assessed these values.