Frogs act as an important indicator of environmental health due to their vulnerability to environmental stressors such as pollutants. It has been well documented that frogs are in decline both in Australia and internationally. Reasons for frog decline in Australia have been attributed to habitat removal, fragmentation or degradation; environmental pollution; climate change; increased ultraviolet-B radiation and increased salinity. In addition, predation or competition from introduced pest species including Cane Toad Bufo (rhinella) marinus and Mosquito Fish Gambusia holbrooki as well as the introduction of diseases such as chytrid fungus (Batrachochytrium) have been demonstrated as factors amphibian decline.
Wetlands in Australia utilised by a variety of taxa, including frogs, have declined over the last century. This is as a result of salinization; acidification; pollution; infill of wetlands for development and changes to inflow as a result of water diversions for agriculture and alterations in climate.
This project focuses on issues associated with habitat removal and aims to look at the benefits that creating artificial habitat through the work of a quarry can have on frogs. The study site in question is a large artificial waterbody, known as Tweed Sands Lake near Tweed Heads in far north east New South Wales, Australia. This waterbody was created by an active sand extraction facility. During site operations, rehabilitation efforts have been carried out in order to revegetate the sections of the lake. Frogs have been demonstrated to inhabit abandoned quarries, so investigation of this active quarry site may provide insight as to the early colonization of artificial waterbodies by amphibians.
This study will investigate if through the construction of the water body, Tweed Sands Lake, and associated efforts to rehabilitate the site during operations, Hanson have potentially created critical amphibian habitat. This study aims to assess whether there is greater diversity and abundance of frogs in rehabilitated or unmanaged parts of the lake, and to provide management advice on future rehabilitation works to maximise chances of colonization.