Wetland ecosystems are extensive in the Cooper GBA region and include key ecological assets such as the Ramsar-listed Coongie Lakes, DIWA-listed lakes and wetlands, as well as habitat for the grey grasswren (Amytornis barbatus barbatus) and the Australian painted snipe (Rostratula australis), and plants and animals with significant cultural and economic values for Indigenous peoples.
Wetlands are defined as swamps, marshes, billabongs, lakes, salt marshes, mudflats, mangroves, coral reefs, fens, peat bogs or bodies of water, natural or artificial, permanent or temporary. Water in wetlands can be static, flowing, fresh brackish or saline and include inland rivers and coastal or marine water to a depth of 6 m at low tide (Department of Agriculture‚ Water and the Environment, 2016). The spatial extent of the wetland vegetation extent and condition endpoint in the Cooper GBA region is 12,143 km2 (about 9%, Figure 12), of which almost half overlies areas that are prospective for unconventional gas resources ( Figure 2 ). Existing disturbance affects about 2% of wetland areas in the Cooper GBA region, including existing infrastructure (167 km2) and seismic surveys (91 km2) (Geological and Bioregional Assessment Program, 2021m).
Wetlands in the Cooper GBA region have highly variable water regimes and water quality dominated by connectivity with Cooper Creek, as well as local rainfall ( Box 8 ). Two wetland types are predominant in the Cooper GBA region: palustrine – vegetated wetlands associated with floodplain environments that include billabongs, swamps, bogs, springs and soaks – and the larger lacustrine wetlands dominated by open-water. Wetlands also occur in other landscapes, such as dune fields of the Strzelecki Desert, where water regimes are dominated by localised rainfall.
The highly variable nature of the water regimes in the region gives rise to high diversity of ecosystems (refer to the wetland vegetation extent and condition endpoint). This includes more than 90 regional ecosystems that provide habitat for thousands of species (Hobbs et al., 2017; Queensland Herbarium, 2018a). Some wetlands support significant congregations of wetland bird species with populations in excess of 20,000 birds (Jaensch, 2009; Butcher and Hale, 2011). Key ecological assets include lakes and wetlands listed in the Directory of important wetlands in Australia, and the Coongie Lakes Ramsar wetland site. Wetlands also provide habitat for the endangered grey grasswren ( Amytornis bartbatus barbatus) and the Australian painted snipe ( Rostratula australis). Like riparian areas, wetland values are culturally important for Indigenous peoples in the region, with plants and animals being significant from cultural and economic perspectives (Constable et al., 2015)
Box 8 Detecting changes to historical flooding associated with gas resource development
Paired-floods analysis (such as comparing flood characteristics of similar sized floods before and after development) suggests historic infrastructure development, including oil and gas fields, has had negligible impacts on flood characteristics. Co-analysis of streamflow data and two satellite remote sensing open water datasets from 2000 to 2020 provides estimates of the baseline frequency and extent of floodplain inundation in the Cooper GBA region (Geological and Bioregional Assessment Program, 2021k).
These baselines distinguish between inundation from floods (such as lateral inflow into the floodplain from the upper parts of the Cooper Creek catchment) and inundation caused by rainfall received on the floodplain. Future development on the floodplain, including gas extraction and associated activities, may impact flood inundation but will not impact rainfall received on the floodplain. Analysis of the 2 satellite datasets reduces uncertainty associated with spatial resolution and frequency of cloud-free observations to better understand the value of these datasets for long-term environmental monitoring.
Direct impacts from development activities are of ‘potential concern’ in up to 33% of wetland areas. Indirect impacts, such as competition and predation, ecosystem burning, and habitat degradation, fragmentation and loss, that could spread beyond development areas are of ‘potential concern’ in almost half of all mapped wetland areas. There is high confidence that direct impacts can be effectively managed on site, primarily by avoiding development in or near wetlands. However, coordinated regional responses and management plans are needed to manage indirect impacts.
Direct disturbance is of ‘potential concern’ in up to 33% of wetland areas (refer to the soil compaction , vegetation removal and vehicle movement node descriptions). Indirect impacts that could spread beyond the development area, disrupting natural processes, are of ‘potential concern’ in up to 49% of wetland areas (refer to the competition and predation , ecosystem burning , and habitat degradation fragmentation and loss node descriptions). Important wetland areas are represented in the causal network by the Coongie Lake Ramsar wetland condition , DIWA lake condition and DIWA wetland condition endpoints.
There is high confidence that development activities can be effectively managed to prevent degradation on site, primarily by avoiding development in or near wetlands. The extent of the potential development area means that direct impacts on important ecological or cultural values can be avoided through considered planning. However, to manage indirect stressors, such as introduced plants, predators and herbivores, coordinated regional responses and management plans are needed.
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- At a glance
- Explore this assessment
- Executive summary
- 1 About the assessment
- 2 About the region
- 3 Assessment, mitigation and monitoring
- 4 Potential impacts on water
- 5 Potential impacts on the environment
- 6 Potential impacts on protected fauna and flora
- 7 Conclusion
- Contributors to the Program