Goulburn Broken CMA has been working to improve habitat on Hughes Creek for Macquarie Perch, a threatened species across the region. In 2015, trial works occurred at three sites to reinstate depth and shelter. Trials to stabilise in-channel sand with sedge and rush planting have also been undertaken. Pre and post monitoring has been established to evaluate the success of these works and to help inform further project investment on the Hughes Creek and other sand affected Macquarie perch refuge streams. To help us to learn more about the project, two interactive story maps have been created. They contain simple instructional tips to help people navigate and access all the available data. We encourage you to explore them below.
Macquarie perch Monitoring: Fish survey records for Macquarie perch in the Hughes Creek
Only eleven Macquarie perch populations remain in Victoria, seven of which are found in the Goulburn Broken catchment. The populations that remain are fragmented and vulnerable as a result of overfishing, vegetation loss and introduced fish, among other things. Drought and climate change further increase the pressures on their survival. Since 2006, fish surveys have been undertaken at the seven sites of Macquarie perch populations in the Goulburn Broken catchment to gain an understanding of the current range of the Macquarie perch population and to collect information on their general health, size distribution and recruitment potential. Instream woody habitat was also assessed at three sites this year.
This monitoring has provided many insights that will help to both plan future works and monitor progress and outcomes over time. The survey results show that at three of the sites, works can be targeted to increase population size and range, increase connectivity between suitable habitat and improve aquatic habitat and spawning areas.
Have a look at the story map for Hughes Creek below for some fabulous photos and informative maps, as well as to find out more about the conditions that Macquarie perch require to prosper, and the details of the survey results. The Hughes Creek results closely resemble successful recruitment years across all streams surveyed for Macquarie perch.
(click on photo below to access story map)
In-stream habitat works trial for Macquarie perch in the Hughes Creek
Investigations have confirmed that Hughes Creek is slowly recovering from a build-up of sand within the stream channel, causing it be more uniform and shallow. However, this does not provide the conditions that Macquarie perch require to prosper. They require:
- Deep pools to reside in with overhanging vegetation or structure for shelter, which are critical refuges throughout periods of low to no flow.
- Connection to riffle sections above which Macquarie perch spawn. Fertile eggs must settle into cavities between rocks and gravel to develop.
- Warming water in the Spring to trigger spawning.
More than 50 structures were installed in May 2015 to enhance stream depth. Other work has been done to establish vegetation, stabilise sand deposits, enhance instream habitat and connectivity, and protect vital habitat that currently exists.
In January 2016 there was a minor flood, in which there was a rapid rise in flow, similar to what was experience in the major flood event of September 2010. This provided an opportunity to assess how the structures would cope with this sort of event. Unfortunately many structures were damaged, however wood that was secured by being partly buried into the bank remained in place, as did rock that was used. As a result, twelve structures were reconstructed, while others that remained were reinforced to ensure that they will remain if a similar event occurs.
Details about habitat structures that have been installed, monitoring that has taken place and other trials that have taken place are available in the story map below.
More information about the Hughes Creek project to restore habitat for Macquarie perch is available on the Goulburn Broken CMA website.