Murray Cod is the largest solely freshwater fish in Australia. It occurs throughout most of the Murray–Darling system, except for the upper reaches of some tributaries in Victoria, the Australian Capital Territory and southern New South Wales. Investigation of the genetic structure in the Murray–Darling Basin has demonstrated that, where there is connectivity between catchments, one large genetically panmictic biological stock exists throughout most of its distribution1. However, genetically distinct populations have been identified in the more isolated Lachlan, Macquarie and Gwydir catchments1. This separation appears to be the result of restricted gene flow due to isolated catchments, but may also be influenced by stocking programs1. Although genetic studies suggest the existence of one biological stock, there are differences in management arrangements and available information in the various jurisdictions.
Here, assessment of stock status is presented at the jurisdictional level—Australian Capital Territory, Queensland, New South Wales, Victoria and South Australia