In line with strengthening climate science action under the Queensland Climate Adaptation Strategy (Q-CAS), a wetlands conservation project is being led by the Department of Environment and Science (DES) for the Coombabah Lake and Creek wetland system on the Gold Coast. DES is set to collaborate with the council of the City of the Gold Coast and to involve key stakeholders and partners for project input, including Jabree Limited.
The estuarine wetland system comprises of both Coombabah Lake and Coombabah Creek and has been classified as having international significance under the Ramsar Convention (part of the Moreton Bay Ramsar site). The system has also been declared a marine national park zone under the Marine Parks (Moreton Bay) Zoning Plan 2019, along with a Fish Habitat Area. The catchment area is quite small, and the lake (approximately 460 Ha in size) extends 15km from its Nerang State Forest headwaters.
Concerns about the decline of the conservation values of the lake and creek have been voiced, following significant past modification of the lake’s catchment zone over time. Specifically, the concerns raised have been in relation to the possible accumulation of sediments and narrowing and shallowing of the creek channel downstream. It is suggested that since the Gold Coast Seaway was built in 1983, Coombabah Lake and Creek have been penetrated by an increased volume of tidal water. Confirmed sea level rising in Queensland (indicated by historical tidal gauge records) has also been observed, and it is predicted this will continue globally with the changing climate, affecting the condition of estuaries and introducing further stress within the surrounding landscape and vegetation.
The development of a climate adaptation management plan is proposed for the site, in consultation with stakeholders. Other key project objectives have been developed and this is proposed to involve the following:
- The identification and investigation of historical changes within the system such as water levels, currents and bathymetry (topography);
- The documentation of the current condition of the system;
- The investigation of vegetation pattern changes in the system; and
- The consideration of how the system and surrounding habitats will respond to the continuation of projected future climate change factors.
These objectives are envisaged to increase the understanding of the historical evolution of the Coombabah wetland system in the context of local sea level rise, changes to bathymetry and vegetation response to these changes. The development of appropriate conservation strategies to appropriately manage the wetland system and assist in its adaptation to the changing climate is also presented as a desired outcome of the project.
This information has been adapted from the DES Coombabah Lake project fact sheet, which can be viewed in further detail at https://wetlandinfo.des.qld.gov.au/resources/static/pdf/resources/fact-sheets/fs-coombabah-factsheet-19012021.pdf
Featured image: Casuarina showing stress as mangrove seedlings expand landwards (Source: Adame 2019)