5.2 Wetland ecosystems

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)

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.