Cell Descriptions - South East Natural Resources Management Board

SE2 – Port MacDonnell
Landforms
This is a low lying undulating coastal plain with swamp muds and beach ridges over limestone.
There are a series of small open embayments, between reefs and low headlands; there is little
onshore sand storage in a narrow low Holocene beach ridge system. Beaches are narrow, with
low foredunes, and wave energy is medium to low, gradually decreasing from E to W along the
cell shoreline. Beach sands are fine to medium, with some shingle; the narrow beach ridges
contain shingle ridges. There are also some coarse sand beaches at the western end of the cell.
At Cape Northumberland aeolianite forms a low undulating plateau, with 20m cliffs and stranded
cliff top dunes. There are extensive shore platforms and nearshore limestone reef that (together
with the large breakwater) shelter Port MacDonald immediately to the east.
Port MacDonnell. Photograph Coast Protection Board 2003.
Benthic Habitat
There is inshore bare sand in Riddoch Bay, west to Stony Point and adjacent headlands where
low profile platform reef extends to the shore. Macdonnell Bay again has inshore bare sand with
patches of low platform reef. There is dense seagrass mapped to 200m off Port Macdonnell; then
bare sand to near Cape Northumberland, where heavy limestone/ calcarenite reef is found
inshore.
Biota
There are 3 flora survey sites, 16 Herbarium record sites, and 57 opportune fauna survey sites.
There is 140 ha of remnant vegetation, i.e. 15.5% of the cell.
The main associations are Leucopogon parviflorus tall shrubland on stranded dunes near Cape
Northumberland; Leptospermum lanigerum tall shrubland on coastal swamps; Eucalyptus obliqua
woodland on hills and slopes.
Recorded fauna species include 215 birds, 21 butterflies, 16 mammals, 12 reptiles and 5
amphibians. Listed species include the EPBC critically endangered Orange-bellied Parrot
Limestone Coast and Coorong Coastal Action Plan 219