Innovative habitat restoration in the Onkaparinga estuary

There’s no one size-fits-all approach to habitat restoration. Every habitat presents a unique mix of characteristics and challenges, often meaning innovation is required. That’s where the OzFish team and our volunteers excel. 

Our Onkaparinga Chapter demonstrated that recently when they took an innovative approach to restoring submerged habitat in the Onkaparinga River as part of our River Resnagging and Fish Hotels Program

They developed a new approach to restoring submerged wooden habitat in the Onkaparinga estuary. Wooden habitat in rivers plays an important role in healthy ecosystems as it provides shelter for juvenile fish and other aquatic species. 

Our volunteer team designed and built a new kind of modular wooden structure, called ‘frustas’ because of their stepped pyramid shape. The design and build process was driven by one Chapter member in particular, Leigh Warman. 

Constructed from recycled oak tree stakes and filled with bundles of eucalyptus sticks, the frustas were placed at strategic points along the river. So far, nine frustas have been installed. 

The team has been supported by Green Adelaide Landscape Board, Marine Parks SA, City of Onkaparinga, and Sea Scouts. 

The reintroduction of these safe places for fish is vitally important to support native species and ensure the long-term sustainability of the Onkaparinga River as a popular fishing spot. Over the years, submerged wood has been systematically removed from the river, for a variety of reasons, resulting in habitat degradation. 

The frustas, with their flat tops that sit below the water’s surface, are also proving popular with birds as places to roost at low tide. Species including cormorants, black ducks, and ibis have been seen making use of them. 

The Chapter has plans to continue working to restore wooden habitats along the Onkaparinga River, including carrying out monitoring activities using underwater cameras to determine how aquatic species are using the new structures. 

So, regardless of the shape or scale of the challenge, the OzFish movement has the expertise and determination to begin tackling it. 

If you want to get involved in supporting us to restore better habitat for better fishing, become a member today.

 


Project partners include Green Adelaide Landscape Board, Marine Parks SA, City of Onkaparinga, and Sea Scouts.