Cod find new log homes
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Artificial habitats are giving the endangered Mary River cod a fighting chance.
Griffith University researchers are testing “cod logs” - artificial nesting habitats created from natural timber - to support the critically endangered Mary River cod in Queensland's Mary River.
Severe weather has degraded the river’s banks and destroyed natural spawning areas, driving the cod population to dangerously low levels.
Experts say the cod logs have shown early success following their installation in July 2024,, with male cod using them to shelter and guard their thousands of eggs and larvae.
Dr Luke Carpenter-Bundhoo, Research Fellow at Griffith's Australian Rivers Institute, leads the project with key collaborators including the Mary River Catchment Coordinating Committee and Jinibara traditional owners.
“Mary River cod are currently listed as endangered and are at particular risk for multiple reasons,” he said.
“The long history of degradation to river banks and habitats, worsened by 2022 floods, has reduced natural spawning and shelter sites.”
The project’s cod logs represent a unique approach in freshwater conservation, following the success of bird boxes and marine artificial reefs.
Fishing also endangers cod nests, with a parent cod briefly removed by anglers often leaving eggs vulnerable to predators.
Dr Carpenter-Bundhoo's team monitors the cod logs using underwater cameras, which provide valuable new insights into cod breeding schedules in the wild.
The ‘cod in a log’ project is part of a $550,000 conservation program funded by the National Environmental Science Program’s (NESP) Resilient Landscapes Hub and Queensland Disaster Recovery arrangements.
“With this funding, we’re drawing on expertise from scientists to help guide protection of this species using methods such as artificial logs … to better protect our precious threatened species and leave nature better off for generations to come,” Environment Minister Tanya Plibersek says.
The NESP Hub, collaborating with state agencies and conservation groups, aims for cost-effective restoration strategies that strengthen natural reproduction and habitat resilience for the Mary River cod and other at-risk species across Queensland’s freshwater ecosystems.