Native freshwater fish and crayfish species are being given a helping hand by scientists and community groups, who are collaborating to restore their habitat.

Murdoch University scientists Dr Stephen Beatty and Associate Professor David Morgan are surveying the heavily modified lower Harvey River in South-West Western Australia to determine where more native-friendly habitats can be created.

The scientists from Murdoch’s Centre for Sustainable Aquatic Ecosystems are working with the Harvey River Restoration Taskforce, Greening Australia, the Peel-Harvey Catchment Council, the Water Corporation and the wider community on the restoration project.

The partners are aiming to restore degraded sites to boost the ecosystem health and recreational fishing opportunities.

Environmental pressures

One of species this work will benefit is the smooth marron - endemic to the South-West region and considered a culinary delicacy.

Fishing for them in the wild is heavily restricted. Environmental pressures including the destruction of riverbank vegetation, increasing salinity, climate change and reduced river flow have seen their range and number reduced.

Dr Beatty said changes to rivers in the South-West to improve irrigation for agriculture had created unfavourable conditions for native fish and crayfish, and enabled invasive species to dominate.

“Recent advances in irrigation practices have provided the opportunity to restore the deep refuge pools with a variety of vegetation preferred by marron,” Dr Beatty said.

“Our first survey a few months ago revealed there are still thousands of juvenile native fishes in certain sites in spring, which is a very promising finding.

“But they are unlikely to survive in those habitats in summer as they are very shallow and devoid of complex habitat. If we can create permanent refuge pools and restore the vegetation along the river banks it will enable them to continue to use these areas of the river year-round.

“This will not only provide benefit to the ecosystems, but also to people living near these rivers as South-West freshwater fishes consume pest mosquito and midges.”

Jennifer Stringer, Community Chair of the Harvey River Restoration Taskforce said the Harvey River was highly valued by the local community for its ecological, economic, social, recreational and cultural services. 

“We hope through this project to engage the local community with activities to improve habitat within the river system to ensure this water resource is available to future generations to enjoy,” Ms Stringer said.

The project is funded by Greening Australia via the Alcoa Foundation, the Peel Harvey Catchment Council via Royalties for Regions Community Services Fund, and the State Natural Resource Management Program.

Free community and school citizen science events will be held at Harvey River in February and March 2019 during the second round of sampling. To get involved please email c.allen@greeningaustralia.org.au.