Population assessment of the endangered Green and Golden Bell Frog Litoria aurea at Port Kembla, New South Wales

The Green and Golden Bell Frog Litoria aurea has declined dramatically in distribution and abundance in NSW during the last 20 years. We describe the dynamics of the population found at Port Kembla near Wollongong, New South Wales during 1994-6. This population was formerly widespread in the region but has contracted to just tour sites, all found within a distance of 5 km. We conducted detailed surveys at three of these sites and a preliminary survey at the fourth site. These surveys revealed that only two of the sites contained breeding habitat that may have any short-term security. One of these breeding sites (Coomaditchy Lagoon) contained high densities of the Mosquito Fish Gambusia affinis, however, tadpole survival and adult recruitment at this site appeared high. In January 1996, more than 400 metaporphlings were observed. Ten months later there was a substantial increase in the number of adult bell frogs present at the site. The other site where significant breeding occurred was within the BHP steel works. There was limited breeding at a third site which has been subjected to development for new housing. The adult frog population appeared to move amongst some sites offering breeding habitat: many residents in the area reported the presence of frogs sheltering on their properties. We provide several management options for this frog population including closer study of the fish-tadpole interaction at the lagoon site. Resolution of this anomaly offers the opportunity to not only secure many existing populations but also to manage unoccupied breeding sites that are currently unavailable to frogs due to the presence of the Mosquito Fish.