Fish stocking is an important tool used to supplement existing fisheries, create new ones and support populations of fish found in rivers, creeks and other waterways. Stocking may be done for the benefit of commercial, recreational or Cultural fishing, but may also be done for ecological conservation to restore or increase the population of threatened/endangered fish species that is pressured by prior overfishing, habitat destruction and/or competition from invasive species. Fish stocking must be done responsibility to protect biodiversity and conserve our unique Australian ecosystems.
Highlights
- Tagged Murray cod have been released in the Edward-Wakool system and in the Baaka (Darling) River in late 2023.
- If you catch one, please contact the NSW DPI on 1800 185 027 or scan the QR code on signs installed at several boat ramps, campgrounds and locations along the Darling River between Bourke and Louth
Usually, Murray cod stocking is done primarily with fingerlings (40-50 mm long cod), however exciting things are happening in the Baaka (Darling) River – approximately 500 “advanced size” Murray Cod are being released. The Department of Primary Industry Fisheries (DPI-Fisheries) is trialling this new method to aid fish recovery after natural disasters. This innovative project is a direct response to the recent fish kills and is being delivered with the help of recreational and Aboriginal cultural fishers.
500 tagged Murray cod averaging 350 mm long and 650 g were released in the Edward-Wakool system in April of 2023 (Figure 1). A similar number of fish were released in the Baaka (Darling) River in November 2023. Both regions will also be stocked with up to 50,000 Murray Cod fingerlings (40-50 mm) during the entire 2023-24 season.
All fish will have external T-bar tags fitted, with 50 of the fish stocked to the Baaka (Darling) River also fitted with surgically implanted acoustic tags. The acoustic tags will allow monitoring of individual fish’s movement and habitat use for tens to hundreds of kilometres up and down the river. The external tags will also allow recreational and Aboriginal cultural fishers to report any catches and inform fishery managers and scientists of fish movement and growth.
The trial stocking of Murray cod fingerlings/sub-adults is designed to complement planned mass stockings of “standard” fingerlings (30-40mm). DPI researchers will assess this method as a future option to aid and/or fast track fishery recovery following natural disasters including floods, droughts and bushfires. The trial will consider risks associated with the increased occurrence and severity of these events as a result of climate change and will assess targeted stocking of advanced sized fish as part of a suite of management responses to safeguard fisheries resources and opportunities. The evaluation will focus on the initial habitat use, movements and survival of stocked larger juveniles/sub-adults.
In addition to the collection of data from acoustic and external tags, targeted electrofishing sampling in the rivers near the stocking sites will add to the whole extensive monitoring program.
Keep a look out for these signs which are installed at several boat ramps, campgrounds and locations along the Darling River between Bourke and Louth (in the vicinity of where these fish were stocked).
How can I help?
The stocking sites are located in the Edward-Wakool system in south-western NSW and the Baaka (Darling) River between Bourke and Louth in western NSW. All fish will have external tags fitted which are most commonly anchored in the muscle of the dorsal fin with metal wires or plastic anchors.
If you catch one, please follow the instructions and let fishery managers know. This will contribute to the vital research.
Where has stocking occurred?
You can find a detailed map of the past stocking events across NSW on the NSW DPI website. Most states require a permit to release fish into public waterways, you can find more information here.
Original publication prepared by 2org
Can ‘Advanced’ Murray Cod Stocking Fast Track River Recovery?
Featured image: Murray cod.
Photo credit: Gunther Schmida
