Endangered Ecological Communities in Coastal Hazard Areas within Shoalhaven LGA 2023

This vector dataset provides updated mapping of the distribution and condition of Endangered Ecological Communities in Shoalhaven City Council’s coastal hazard areas. The report and mapping also includes updated mapping of Endangered Ecological Communities within tidal inundation risk areas within the Lower Shoalhaven River, St Georges Basin, Sussex Inlet, Berrara Creek and Lake Conjola.

Ecoplanning were engaged by Shoalhaven City Council to conduct an assessment of Endangered Ecological Communities at 15 sites within the Shoalhaven Local Government Area. The sites are made up of a combination of nine Coastal Erosion sites and six Tidal Inundation sites. 

Regional vegetation mapping (Department of Planning and Environment 2013) identified that six Endangered Ecological Communities had been previously mapped within the study area including:
<ul>
<li>Bangalay Sand Forest in the Sydney Basin and South East Corner Bioregions</li>
<li>Swamp Oak Floodplain Forest on coastal floodplains of the NSW North Coast, Sydney Basin and South East Corner Bioregions.</li>
<li>Coastal Saltmarsh in the NSW North Coast Sydney Basin and South East Corner Bioregions.</li>
<li>Swamp Sclerophyll Forest on Coastal Floodplains of the NSW North Coast, Sydney Basin and South East Corner Bioregions.</li>
<li>Freshwater Wetlands on Coastal Floodplains of the NSW North Coast, Sydney Basin and South East Corner Bioregions.</li>
<li>Littoral Rainforest in the NSW North Coast, Sydney Basin and South East Corner Bioregions.</li>
</ul>

With the exception of Littoral Rainforest, the remainder of these coastal Endangered Ecological Communities were recorded within the study area. A total of 105.53 ha of the study area was identified as supporting Endangered Ecological Communities, including 87.02 ha in the Tidal Inundation study area and 18.51 ha in the Coastal Erosion study area. Bangalay Sand Forest and Swamp Oak Floodplain Forest were the most widespread communities, accounting for 91.39 ha of the 105.53 ha of endangered ecological community (EEC) vegetation recorded respectively. Generally, the mapping produced from field survey conforms reasonably closely to existing vegetation mapping. 

A total of 23 Biodiversity Assessment Method (2020) plots were completed to assess the Endangered Ecological Communities present in a standardised and robust way. These plots determined that the vegetation within the Coastal Erosion and Tidal Inundation study areas was in moderate to good condition with Vegetation Integrity scores ranging from VI 32.8 to VI 70.1. 

Whilst systematic threatened species surveys were beyond the scope of this assessment, one threatened flora species was incidentally recorded during field survey. Approximately 40 Melaleuca biconvexa plants were observed in vegetation to the north of St Georges Basin Sports Ground, south of The Wool Road. It is anticipated that the population size would be higher, and potentially significantly higher, if parallel field traverses were conducted. 

Based on the higher cover and diversity of High Threat Exotic (HTE) species present within Bangalay Sand Forest, compared to Swamp Oak Floodplain Forest, it is recommended that the former be prioritised for weed management activities. Likewise, it was noted that the Coastal Erosion sites (containing Bangalay Sand Forest) had a higher cover of HTEs than the Tidal Inundation sites, therefore the former should also be prioritised for weed management actions.

Note that this dataset contains topology errors (41 overlapped polygons) so should be not used for analysis or area hectare reporting.

Tags: Coastal Hazards, Shoalhaven
Organization: Shoalhaven City Council