Environmental flows to support Murray cod spawning in the lower Darling River 2017

About the document

• In 2017–18, ~25 gigalitres of water for the environment was delivered to support Murray cod spawning and the survival of Murray cod and golden perch juveniles (referred to as ‘recruitment’). It aimed to build on the outcomes and experiences from flows delivered down the Darling the previous year.
• This study aimed to document the spatial and temporal dynamics of Murray cod spawning in the lower Darling River, defines the Murray cod spawning period and compares findings to patterns of spawning observed in previous years.
• The spawning response of Murray cod in 2017, gauged by the number of larvae collected, was considerably lower than that recorded in 2016.
• The number of larvae was however much higher than in 2014 when conditions in the lower Darling River were not optimised to support spawning, flows were low and oscillating.
• The abundance of Murray cod larvae recorded in 2017 was similar to that observed from other rivers and streams where stable, perennial flow regimes prevail, such as the nearby lower Murray River and Mullaroo Creek, mid-Murray and Ovens River’s and in Gunbower Creek.
• Targeted use of environmental water in 2016 and 2017 provided excellent value in supporting the Murray cod population, demonstrating that environmental managers are able to maximise spawning and recruitment opportunities for Murray cod in the lower Darling River, thus building the population’s resilience to disturbances into the future

Further information

• Environmental flows in the Darling River to support native fish populations 2016–17
• Assessment of Murray cod recruitment to the lower Darling River in response to environmental flows throughout 2016–18