The Upper Billabong Creek catchment, surrounding Holbrook, NSW, supports one of the few remaining populations of the endangered Southern Pygmy Perch (Nannoperca australis). In January 2024, a survey to assess the diversity and abundance of fish species in this region, focusing on the Southern Pygmy Perch was conducted. The study aimed to evaluate the current status of fish communities and the effectiveness of ongoing habitat rehabilitation efforts led by Holbrook Landcare Network.
The survey encompassed 29 sites across three tributaries: Spring Creek, 10 Mile Creek, and Mountain Creek. Sampling methods included backpack electrofishing, which recorded a total of 1,188 native fish from five species and 450 non-native fish from three introduced species. Notably, compared to sampling undertaken in 2018, the Southern Pygmy Perch was the most abundant native species, indicating a positive response to habitat restoration initiatives.
The results suggest that recent wet conditions and targeted rehabilitation efforts have significantly benefited native fish populations, particularly the Southern Pygmy Perch. Ongoing and future restoration projects, such as leaky weirs, cross vane weirs, and riparian vegetation enhancement, are crucial for maintaining water in the landscape and improving aquatic biodiversity. This study underscores the value of collaborative conservation efforts in sustaining endangered species and promoting ecological resilience in the Upper Billabong Creek catchment.