The successful re-introduction of the Southern Pygmy Perch at a new home along the Pudman Creek in New South Wales has strengthened efforts to increase the spread and survival of this threatened native fish. The Southern Pygmy Perch (Nannoperca australis), is a small, attractive native fish, once found in most areas of the Murray and lower Murrumbidgee catchments in NSW. During the past 25 years they have disappeared from most of their natural range in response to habitat degradation, particularly the loss of aquatic vegetation and associated macroinvertebrates.
Only three populations are known to exist in NSW, one of which was recently discovered in a tributary to the Lachlan River north of Yass. During the height of the drought, this creek ceased to flow and many of the pools containing Pygmy Perch were becoming low and drying out. In a bid to save this isolated population, some of the fish were taken to the Narrandera Fisheries Centre, NSW, with the aim of returning them to the creek once the drought had passed. Obviously happy in their new home, the fish bred, and concurrent surveys at their original home on the creek indicated fish numbers were still high. As a result it was decided an alternative site could be used for the release of the Pygmy Perch and their progeny, to further distribute and protect the species.
New home for native fish
The Pudman Creek, located in an adjacent catchment in the Upper Lachlan, was identified as suitable due to its unusually high abundance and diversity of water plants (one of the main habitat requirements for the Perch), and a characteristic missing from many of our river and creek systems. In addition, there are no introduced fish species in the creek which is a rarity in the Lachlan Catchment. Landholders along the Pudman Creek had long decided there were no fish in the creek except for a few trout which died out in the drought. After being told there were good populations of small native fish they agreed to work with the project, but were not interested because the fish were too small to catch.
Since then, and through the implementation of a partnership project titled ‘Pygmy Perch in the Pudman’, landholders along the creek have learnt to appreciate the small fish and are enthusiastic about protecting their special fish. The project is part of the Boorowa River Recovery – a large scale riparian rehabilitation program which rehabilitated 80 kilometres (654 hectares) of riparian zone within the Boorowa catchment. Approximately 20kms of streams in the Pudman Creek catchment have been rehabilitated (fenced and revegetated using locally native species), with a focus on linking riparian remnant vegetation and reducing sedimentation.
A community fish survey using electrofishing and bait traps was carried out in 2010 with Department of Primary Industries Fisheries and members of the Boorowa Landcare Group, and 12 Pygmy Perch were found in the creek, along with other native fish such as the Flathead Gudgeon. Surveys in 2012 showed the Pygmy Perch are surviving well in their new home, but surveys in locations downstream did not show evidence of them spreading. Riparian habitat along the Pudman Creek is fragmented and revegetation is likely to take many years to reach maturity and ecological complexity. This is why working with landholders to protect existing riparian remnants is a priority.
Further monitoring of fish populations is planned for the next few years to provide a better picture of native fish populations, and the survival and spread of the Pygmy Perch. The community are central to this work and have shown significant enthusiasm to protect their creek not only for the fish but for biodiversity, water quality and the whole ecosystem. The Boorowa River Recovery program work is also expected to continue with the recent announcement of funding from the Australian Government’s Biodiversity Fund Rivers of Carbon project. Rivers of Carbon is being managed by the Australian River Restoration Centre in partnership with Greening Australia.
Acknowledgements: Pygmy Perch in the Pudman is a partnership project between Greening Australia, Lachlan Catchment Management Authority, Boorowa Landcare, NSW Department of Primary Industry Fisheries and local landholders. It was funded through the NSW Environmental Trust and TransGrid.