Cell Descriptions - South East Natural Resources Management Board

SE11 – Guichen Bay
Landforms
This cell is entirely a low, nearly flat coastal plain, of 82 dune ridges and a beach of fine to
medium sands. The landforms around Guichen Bay provide a significant record of late Holocene
to Recent coastal sedimentation (Short & Hesp 1984, p.73). Lower levels of the Robe Range and
possible breaching, allowed the rising late Holocene seas to flood the inter-range depression in
front of the Woakwine Range. Large quantities of sand were swept into this depression and low
energy shoaling waves constructed a series of low beach ridges, dated between 7,000 and 3,000
BP, (Thom et al, 1981). This the largest sediment trap of marine sands on the South East coast,
and 86% of this cell is classified coastal dune. The current foredune is stable, with small scale
storm blowouts and human damage. Between the dune ridges and the Woakwine Range, small
backbarrier swamps, such as Dawson Swamp and McInnes Wetland, are trapped.
Beaches are reflective to intermediate around Guichen Bay, with low beachface angles and
fine/medium carbonate sands. Energy is lowest at the two ends of the bay; at Robe the pattern of
refracted swell slowly drives sand past small indentations to create minor beach management
problems.
Beach ridges Guichen Bay. Photograph Coast Protection Board 2003.
Biota
There are 8 flora survey sites, 13 Herbarium record sites, 3 fauna survey sites, and 41 opportune
fauna survey sites. 19.7% of the cell is vegetated, a total of 1084ha.
The partly grazed dunes are clothed in shrubs and grasses: tall to medium shrubland of Leucopogon
parviflorus, Acacia longiflora var.sophorae, Olearia axillaris+/- Myoporum insulare. Lepidosperma gladiatum
and Isolepsis nodosa is common in the interdune swales. McInnes Swamp retains Leptospermum
lanigerum shrubland. Stands of Eucalyptus diversifolia and Melaleuca halmaturorum are found near the
outlet of drain L.
151 fauna species have been recorded in the cell including 125 birds, 7 butterflies, 8 mammals, 4
reptiles and 7 amphibians. Listed threatened species include the State endangered White-bellied
Limestone Coast and Coorong Coastal Action Plan 402