Home / Projects / Fish Emergency Recovery / Mongarlowe River, NSW

Mongarlowe River and the Macquarie Perch

At the end of 2019, prolonged drought impacts and then widespread bushfire, followed by subsequent rainfall, saw some of Australia’s most precious and unique waterways destroyed.

OzFish and Landcare Australia have joined forces to help threatened species which suffered from the Black Summer fires thanks to the Landcare Australia Aquatic Wildlife Habitat Bushfire Program.

A chance to recover

The OzFish Eurobodalla Chapter are working with a landholder to install 2.5 kilometres of fencing, which will protect more than 70 hectares of river banks from livestock trampling and grazing, giving native vegetation a chance to recover from the fires.

The property on the Mongarlowe River in Tomboye, adjacent to previous improvement works for the species, was severely degraded by the bushfires. The area of the catchment is susceptible to significant erosion. Previous works upstream of the site aimed at improving the stability of banks and sedimentation.

As part of this project, additional erosion and sedimentation control are also being implemented in gullies when required and where bank collapse has occurred to protect the important riffle habitat from a build-up of sediment.

OzFish and its volunteers from the local OzFish Eurobodalla Chapter and Landcare will also be carrying out water quality, eDNA sampling and waterbug testing during an upcoming community education day to determine the species of fish in the system, monitor the population of Macquarie Perch in the system, and determine basic metrics indicating overall health of the waterway through citizen science.

A cause for concern

The Mongarlowe River is a perennial river of the Shoalhaven catchment, located in the Southern Tablelands of NSW. It has long been known that there is a population of Macquarie perch (Macquaria australasica), an endangered fish, in the Mongarlowe River and its tributaries.

However, a prolonged low level or complete lack of recruitment has raised concern about the future of the population in the Mongarlowe River. To exacerbate matters, the viability of the Mongarlowe River population has been likely suppressed by extended droughts, and further inhibited by the 2020 Bushfires and following rainfall and flooding events.

Habitat availability

Sedimentation, or a build up of sediment, as a result of catchment erosion impacts Macquarie Perch directly, as it reduces the riffles available in the system required for spawning.

Macquarie Perch have been recently recorded a few kilometres downstream of the property, and this project has been aimed at promoting further collaboration between existing fishing and Landcare groups, such as Friends of Mongarlowe, who have previously worked together closely on Macquarie Perch projects in the catchment.

This project aims to help the populations of perch by ensuring the fish have the habitat needed to breed and thrive.

The Landcare Australia Aquatic Wildlife Habitat Bushfire Program is funded by the Australian Government’s Wildlife and Habitat Bushfire Recovery program.