Coastal environments provide critical ecosystem services to support biodiversity for a variety of organisms through transitions between marine, freshwater and land habitats. However, these systems are threatened by climate change and human development, especially regarding densely populated regions such as Australia’s eastern coastline of New South Wales (NSW). This area contains 184 estuaries, including Closed and Open Lakes and Lagoons (ICOLLS) which provide critical habitats for these species. Amphibians are heavily understudied in the context of coastal environment despite the threats from habitat loss, pollution and chytrid fungus. This study investigates the relationship between salinity, water level and frog call intensity of the endangered green and golden bell frog (Litoria aurea) in brackish coastal wetlands, using Avoca Lagoon (NSW) as a case example. Data from collecting audio recordings and water parameter measurements determined significant negative correlations between frog call intensity, salinity, and water level, with a notable interaction effect. It was found that optimal breeding conditions occurred within a range for salinities (5.34–6.96 ppt) and water levels (1.24–1.33 mAHD), highlighting the importance of interdisciplinary monitoring techniques. This study provides insight into managing highly dynamic coastal systems to enhance habitat suitability for species such as the green and golden bell frog, ensuring their resilience in the face of future challenges.