Mary River Cod
Conservation in Noosa Shire
Populations of the endangered Mary River cod have declined significantly since European settlement due to land clearing, habitat loss, overfishing, invasive species and extreme weather events.
Native to the Mary River catchment, this iconic freshwater fish can be found within the Noosa Shire, residing in the upper headwaters of the Mary River Catchment. The apex predator relies on complex instream habitat such as hollow logs, undercut banks and deep pools shaded by healthy riparian vegetation. These features provide essential ambush opportunities, shelter and breeding habitat for the species.
Conservation Programs for the Mary River Cod
Noosa Shire Council has a long history of partnering with regional catchment management organisations, including the Mary River Catchment Coordinating Committee and Burnett Mary Regional Group - to deliver conservation projects for the Mary River Cod. This includes an extensive baseline survey across the Noosa Shire and wider Mary River Catchment during 2023, which surveyed populations of the endangered fish, along with assessing in-stream cod habitat and restoration sites.
Juvenile Mary River cod being measured and weighed
The Cod Hollow Log Project
In 2024, The Mary River Catchment Coordinating Committee launched the Hollow Logs for Cod Habitat Program, with a number of partnering organisations. Several weeks later, in one of the hollows in the upper Mary, a large male cod was filmed fanning a substantial number of eggs. Since then, a number of cod and many other species have been documented using the cod hollows. More information on the successful program can be found here: https://mrccc.org.au/hollow-logs-for-cod-habitat/
Noosa Council has continued our partnership in this important program through supporting the installations of around 16 cod logs within the Noosa Shire.
Noosa Shire Cod Log Installations
Mary River Cod demonstrate strong preferences for large, double entry hollow logs. Usually, such logs are carved by specialised arborists, although rare opportunities present themselves from time to time to recycle suitable hollow logs which naturally fall on roads or within road verges (requiring removal to maintain traffic safety standards).
While it is always a shame to see such mature trees fall, this is a natural process and often exacerbated by storm activity, such as the events in November 2025. Noosa Council Environment Services were fortunate to identify a few fallen trees available for use, which already contained large natural hollows. Staff and the community are always pleased to see these hollows create new opportunities for threatened species - such as the Mary River Cod.
Hollows carved from recycled logs
Monitoring
With successful occupation of the hollow logs by spawning cod already documented, Council and the Mary River Catchment Coordinating Committee will continue specialised camera monitoring programs to further document the occupation and spawning potential of this important instream habitat.